EC 4.2.3.162     Relevance: 100%
Accepted name: (–)-α-amorphene synthase
Reaction: (2E,6E)-farnesyl diphosphate = (–)-α-amorphene + diphosphate
Glossary: (–)-α-amorphene = (1S,4aR,8aS)-4,7-dimethyl-1-(propan-2-yl)-1,2,4a,5,6,8a-hexahydronaphthalene
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase [cyclizing, (–)-α-amorphene-forming]
Comments: The enzyme, found in the bacterium Streptomyces viridochromogenes, is specific for (2E,6E)-farnesyl diphosphate and produces only (–)-α-amorphene.
References:
1.  Rabe, P. and Dickschat, J.S. Rapid chemical characterization of bacterial terpene synthases. Angew. Chem. Int. Ed. Engl. 52 (2013) 1810–1812. [PMID: 23307484]
2.  Rinkel, J., Rabe, P., Garbeva, P. and Dickschat, J.S. Lessons from 1,3-hydride shifts in sesquiterpene cyclizations. Angew. Chem. Int. Ed. Engl. 55 (2016) 13593–13596. [PMID: 27666571]
3.  Rabe, P., Schmitz, T. and Dickschat, J.S. Mechanistic investigations on six bacterial terpene cyclases. Beilstein J. Org. Chem. 12 (2016) 1839–1850. [PMID: 27829890]
[EC 4.2.3.162 created 2017]
 
 
EC 4.2.3.95     Relevance: 38.9%
Accepted name: (-)-α-cuprenene synthase
Reaction: (2E,6E)-farnesyl diphosphate = (-)-α-cuprenene + diphosphate
Other name(s): Cop6
Systematic name: (-)-α-cuprenene hydrolase [cyclizing, (-)-α-cuprenene-forming]
Comments: The enzyme from the fungus Coprinopsis cinerea produces (-)-α-cuprenene with high selectivity.
References:
1.  Lopez-Gallego, F., Agger, S.A., Abate-Pella, D., Distefano, M.D. and Schmidt-Dannert, C. Sesquiterpene synthases Cop4 and Cop6 from Coprinus cinereus: catalytic promiscuity and cyclization of farnesyl pyrophosphate geometric isomers. ChemBioChem 11 (2010) 1093–1106. [PMID: 20419721]
[EC 4.2.3.95 created 2012]
 
 
EC 4.2.3.6     Relevance: 27.1%
Accepted name: trichodiene synthase
Reaction: (2E,6E)-farnesyl diphosphate = trichodiene + diphosphate
Other name(s): trichodiene synthetase; sesquiterpene cyclase; trans,trans-farnesyl-diphosphate sesquiterpenoid-lyase
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase (cyclizing, trichodiene-forming)
References:
1.  Hohn, T.M. and Vanmiddlesworth, F. Purification and characterization of the sesquiterpene cyclase trichodiene synthetase from Fusarium sporotrichioides. Arch. Biochem. Biophys. 251 (1986) 756–761. [PMID: 3800398]
2.  Hohn, T.M. and Beremand, P.D. Isolation and nucleotide sequence of a sesquiterpene cyclase gene from the trichothecene-producing fungus Fusarium sporotrichioides. Gene 79 (1989) 131–138. [PMID: 2777086]
3.  Rynkiewicz, M.J., Cane, D.E. and Christianson, D.W. Structure of trichodiene synthase from Fusarium sporotrichioides provides mechanistic inferences on the terpene cyclization cascade. Proc. Natl. Acad. Sci. USA 98 (2001) 13543–13548. [PMID: 11698643]
[EC 4.2.3.6 created 1989 as EC 4.1.99.6, transferred 2000 to EC 4.2.3.6]
 
 
EC 2.4.1.371     Relevance: 25%
Accepted name: polymannosyl GlcNAc-diphospho-ditrans,octacis-undecaprenol 2,3-α-mannosylpolymerase
Reaction: (1) 2 GDP-α-D-mannose + [α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol = 2 GDP + α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
(2) 2 GDP-α-D-mannose + α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol = 2 GDP + [α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n+1-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbdA
Systematic name: GDP-α-D-mannose:α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol 2,3-α-mannosyltransferase (configuration-retaining)
Comments: The enzyme is involved in the biosynthesis of polymannose O-polysaccharide in the outer leaflet of the membrane of Escherichia coli serotype O9a. The enzymes consists of two domains that are responsible for the 1→2 and 1→3 linkages, respectively.
References:
1.  Greenfield, L.K., Richards, M.R., Li, J., Wakarchuk, W.W., Lowary, T.L. and Whitfield, C. Biosynthesis of the polymannose lipopolysaccharide O-antigens from Escherichia coli serotypes O8 and O9a requires a unique combination of single- and multiple-active site mannosyltransferases. J. Biol. Chem. 287 (2012) 35078–35091. [PMID: 22875852]
2.  Greenfield, L.K., Richards, M.R., Vinogradov, E., Wakarchuk, W.W., Lowary, T.L. and Whitfield, C. Domain organization of the polymerizing mannosyltransferases involved in synthesis of the Escherichia coli O8 and O9a lipopolysaccharide O-antigens. J. Biol. Chem. 287 (2012) 38135–38149. [PMID: 22989876]
3.  Liston, S.D., Clarke, B.R., Greenfield, L.K., Richards, M.R., Lowary, T.L. and Whitfield, C. Domain interactions control complex formation and polymerase specificity in the biosynthesis of the Escherichia coli O9a antigen. J. Biol. Chem. 290 (2015) 1075–1085. [PMID: 25422321]
[EC 2.4.1.371 created 2019]
 
 
EC 5.3.3.11     Relevance: 24.5%
Accepted name: isopiperitenone Δ-isomerase
Reaction: isopiperitenone = piperitenone
Systematic name: isopiperitenone Δ84-isomerase
Comments: Involved in the biosynthesis of menthol and related monoterpenes in peppermint (Mentha piperita) leaves.
References:
1.  Kjonaas, R.B., Venkatachalam, K.V. and Croteau, R. Metabolism of monoterpenes: oxidation of isopiperitenol to isopiperitenone, and subsequent isomerization to piperitenone by soluble enzyme preparations from peppermint (Mentha piperita) leaves. Arch. Biochem. Biophys. 238 (1985) 49–60. [PMID: 3885858]
[EC 5.3.3.11 created 1989]
 
 
EC 1.1.1.243     Relevance: 23.1%
Accepted name: carveol dehydrogenase
Reaction: (–)-trans-carveol + NADP+ = (–)-carvone + NADPH + H+
Other name(s): (–)-trans-carveol dehydrogenase
Systematic name: (–)-trans-carveol:NADP+ oxidoreductase
References:
1.  Gershenzon, J., Maffei, M. and Croteau, R. Biochemical and histochemical-localization of monoterpene biosynthesis in the glandular trichomes of spearmint (Mentha spicata). Plant Physiol. 89 (1989) 1351–1357. [PMID: 16666709]
[EC 1.1.1.243 created 1992]
 
 
EC 2.4.1.267     Relevance: 23%
Accepted name: dolichyl-P-Glc:Man9GlcNAc2-PP-dolichol α-1,3-glucosyltransferase
Reaction: dolichyl β-D-glucosyl phosphate + α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol + dolichyl phosphate
Other name(s): ALG6; Dol-P-Glc:Man9GlcNAc2-PP-Dol α-1,3-glucosyltransferase; dolichyl β-D-glucosyl phosphate:D-Man-α-(1→2)-D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→6)]-D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol α-1,3-glucosyltransferase
Systematic name: dolichyl β-D-glucosyl-phosphate:α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 3-α-D-glucosyltransferase (configuration-inverting)
Comments: The successive addition of three glucose residues by EC 2.4.1.267, EC 2.4.1.265 (Dol-P-Glc:Glc1Man9GlcNAc2-PP-Dol α-1,3-glucosyltransferase) and EC 2.4.1.256 (Dol-P-Glc:Glc2Man9GlcNAc2-PP-Dol α-1,2-glucosyltransferase) represents the final stage of the lipid-linked oligosaccharide assembly.
References:
1.  Reiss, G., te Heesen, S., Zimmerman, J., Robbins, P.W. and Aebi, M. Isolation of the ALG6 locus of Saccharomyces cerevisiae required for glucosylation in the N-linked glycosylation pathway. Glycobiology 6 (1996) 493–498. [PMID: 8877369]
2.  Runge, K.W., Huffaker, T.C. and Robbins, P.W. Two yeast mutations in glucosylation steps of the asparagine glycosylation pathway. J. Biol. Chem. 259 (1984) 412–417. [PMID: 6423630]
3.  Westphal, V., Xiao, M., Kwok, P.Y. and Freeze, H.H. Identification of a frequent variant in ALG6, the cause of congenital disorder of glycosylation-Ic. Hum. Mutat. 22 (2003) 420–421. [PMID: 14517965]
[EC 2.4.1.267 created 2011, modified 2012]
 
 
EC 2.7.1.181     Relevance: 23%
Accepted name: polymannosyl GlcNAc-diphospho-ditrans,octacis-undecaprenol kinase
Reaction: ATP + α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol = ADP + 3-O-phospho-α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbdD; ATP:α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Man-(1→3)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol 3-phosphotransferase
Systematic name: ATP:α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol 3-phosphotransferase
Comments: The enzyme is involved in the biosynthesis of the polymannose O-polysaccharide in the outer leaflet of the membrane of Escherichia coli serotype O9a. O-Polysaccharide structures vary extensively because of differences in the number and type of sugars in the repeat unit. The dual kinase/methylase WbdD also catalyses the methylation of 3-phospho-α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol (cf. EC 2.1.1.294, 3-O-phospho-polymannosyl GlcNAc-diphospho-ditrans,octacis-undecaprenol 3-phospho-methyltransferase).
References:
1.  Clarke, B.R., Cuthbertson, L. and Whitfield, C. Nonreducing terminal modifications determine the chain length of polymannose O antigens of Escherichia coli and couple chain termination to polymer export via an ATP-binding cassette transporter. J. Biol. Chem. 279 (2004) 35709–35718. [PMID: 15184370]
2.  Clarke, B.R., Greenfield, L.K., Bouwman, C. and Whitfield, C. Coordination of polymerization, chain termination, and export in assembly of the Escherichia coli lipopolysaccharide O9a antigen in an ATP-binding cassette transporter-dependent pathway. J. Biol. Chem. 284 (2009) 30662–30672. [PMID: 19734145]
3.  Clarke, B.R., Richards, M.R., Greenfield, L.K., Hou, D., Lowary, T.L. and Whitfield, C. In vitro reconstruction of the chain termination reaction in biosynthesis of the Escherichia coli O9a O-polysaccharide: the chain-length regulator, WbdD, catalyzes the addition of methyl phosphate to the non-reducing terminus of the growing glycan. J. Biol. Chem. 286 (2011) 41391–41401. [PMID: 21990359]
4.  Liston, S.D., Clarke, B.R., Greenfield, L.K., Richards, M.R., Lowary, T.L. and Whitfield, C. Domain interactions control complex formation and polymerase specificity in the biosynthesis of the Escherichia coli O9a antigen. J. Biol. Chem. 290 (2015) 1075–1085. [PMID: 25422321]
[EC 2.7.1.181 created 2014, modified 2017]
 
 
EC 2.4.1.265     Relevance: 22.8%
Accepted name: dolichyl-P-Glc:Glc1Man9GlcNAc2-PP-dolichol α-1,3-glucosyltransferase
Reaction: dolichyl β-D-glucosyl phosphate + α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = α-D-Glc-(1→3)-α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol + dolichyl phosphate
Other name(s): ALG8; Dol-P-Glc:Glc1Man9GlcNAc2-PP-Dol α-1,3-glucosyltransferase; dolichyl β-D-glucosyl phosphate:D-Glc-α-(1→3)-D-Man-α-(1→2)-D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→6)]-D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol α-1,3-glucosyltransferase
Systematic name: dolichyl β-D-glucosyl-phosphate:α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 3-α-D-glucosyltransferase (configuration-inverting)
Comments: The successive addition of three glucose residues by EC 2.4.1.267 (dolichyl-P-Glc:Man9GlcNAc2-PP-dolichol α-1,3-glucosyltransferase), EC 2.4.1.265 and EC 2.4.1.256 (dolichyl-P-Glc:Glc2Man9GlcNAc2-PP-dolichol α-1,2-glucosyltransferase) represents the final stage of the lipid-linked oligosaccharide assembly.
References:
1.  Stagljar, I., te Heesen, S. and Aebi, M. New phenotype of mutations deficient in glucosylation of the lipid-linked oligosaccharide: cloning of the ALG8 locus. Proc. Natl. Acad. Sci. USA 91 (1994) 5977–5981. [PMID: 8016100]
2.  Runge, K.W. and Robbins, P.W. A new yeast mutation in the glucosylation steps of the asparagine-linked glycosylation pathway. Formation of a novel asparagine-linked oligosaccharide containing two glucose residues. J. Biol. Chem. 261 (1986) 15582–15590. [PMID: 3536907]
3.  Chantret, I., Dancourt, J., Dupre, T., Delenda, C., Bucher, S., Vuillaumier-Barrot, S., Ogier de Baulny, H., Peletan, C., Danos, O., Seta, N., Durand, G., Oriol, R., Codogno, P. and Moore, S.E. A deficiency in dolichyl-P-glucose:Glc1Man9GlcNAc2-PP-dolichyl α3-glucosyltransferase defines a new subtype of congenital disorders of glycosylation. J. Biol. Chem. 278 (2003) 9962–9971. [PMID: 12480927]
[EC 2.4.1.265 created 2011, modified 2012]
 
 
EC 2.4.1.256     Relevance: 22.3%
Accepted name: dolichyl-P-Glc:Glc2Man9GlcNAc2-PP-dolichol α-1,2-glucosyltransferase
Reaction: dolichyl β-D-glucosyl phosphate + α-D-Glc-(1→3)-α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = dolichyl phosphate + α-D-Glc-(1→2)-α-D-Glc-(1→3)-α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol
Other name(s): ALG10; Dol-P-Glc:Glc2Man9GlcNAc2-PP-Dol α-1,2-glucosyltransferase; dolichyl β-D-glucosyl phosphate:D-Glc-α-(1→3)-D-Glc-α-(1→3)-D-Man-α-(1→2)-D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→6)]-D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol 2-α-D-glucosyltransferase
Systematic name: dolichyl β-D-glucosyl-phosphate:α-D-Glc-(1→3)-α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol α-1,2-glucosyltransferase (configuration-retaining)
Comments: This eukaryotic enzyme performs the final step in the synthesis of the lipid-linked oligosaccharide, attaching D-glucose in an α-1,2-linkage to the outermost D-glucose in the long branch. The lipid-linked oligosaccharide is involved in N-linked protein glycosylation of selected asparagine residues of nascent polypeptide chains in eukaryotic cells.
References:
1.  Burda, P. and Aebi, M. The ALG10 locus of Saccharomyces cerevisiae encodes the α-1,2 glucosyltransferase of the endoplasmic reticulum: the terminal glucose of the lipid-linked oligosaccharide is required for efficient N-linked glycosylation. Glycobiology 8 (1998) 455–462. [PMID: 9597543]
[EC 2.4.1.256 created 2011, modified 2012]
 
 
EC 2.4.1.378     Relevance: 22.2%
Accepted name: GDP-mannose:α-L-Rha-(1→3)-α-D-Gal-PP-Und α-1,4-mannosyltransferase
Reaction: GDP-α-D-mannose + α-L-Rha-(1→3)-α-D-Gal-PP-Und = GDP + α-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und
Glossary: α-L-Rha-(1→3)-α-D-Gal-PP-Und = α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
α-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und = α-D-mannopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaU (gene name); rfbU (gene name)
Systematic name: GDP-α-D-mannose:α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 4II-α-rhamnosyltransferase (configuration-retaining)
Comments: The enzyme from Salmonella participates in the biosynthesis of the repeat unit of O antigens produced by strains that belong to the A, B, and D1 groups.
References:
1.  Liu, D., Haase, A.M., Lindqvist, L., Lindberg, A.A. and Reeves, P.R. Glycosyl transferases of O-antigen biosynthesis in Salmonella enterica: identification and characterization of transferase genes of groups B, C2, and E1. J. Bacteriol. 175 (1993) 3408–3413. [PMID: 7684736]
[EC 2.4.1.378 created 2021]
 
 
EC 2.3.1.303     Relevance: 22.1%
Accepted name: α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und 2IV-O-acetyltransferase
Reaction: acetyl-CoA + α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = CoA + 2-O-acetyl-α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und
Glossary: α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = α-L-rhamnopyranosyl-(1→2)-α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): rfbL (gene name); wbaL (gene name)
Systematic name: acetyl-CoA:α-L-rhamnopyranosyl-(1→2)-α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 2IV-O-acetyltransferase
Comments: The enzyme, present in Salmonella strains that belong to group C2, participates in the biosynthesis of the repeat unit of O antigens produced by these strains.
References:
1.  Brown, P.K., Romana, L.K. and Reeves, P.R. Molecular analysis of the rfb gene cluster of Salmonella serovar muenchen (strain M67): the genetic basis of the polymorphism between groups C2 and B. Mol. Microbiol. 6 (1992) 1385–1394. [PMID: 1379320]
2.  Liu, D., Lindqvist, L. and Reeves, P.R. Transferases of O-antigen biosynthesis in Salmonella enterica: dideoxyhexosyltransferases of groups B and C2 and acetyltransferase of group C2. J. Bacteriol. 177 (1995) 4084–4088. [PMID: 7541787]
3.  Zhao, X., Dai, Q., Jia, R., Zhu, D., Liu, M., Wang, M., Chen, S., Sun, K., Yang, Q., Wu, Y. and Cheng, A. two novel Salmonella bivalent vaccines confer dual protection against two Salmonella serovars in mice. Front Cell Infect Microbiol 7:391 (2017). [PMID: 28929089]
[EC 2.3.1.303 created 2021]
 
 
EC 3.2.1.24     Relevance: 22.1%
Accepted name: α-mannosidase
Reaction: Hydrolysis of terminal, non-reducing α-D-mannose residues in α-D-mannosides
Other name(s): α-D-mannosidase; p-nitrophenyl-α-mannosidase; α-D-mannopyranosidase; 1,2-α-mannosidase; 1,2-α-D-mannosidase; exo-α-mannosidase
Systematic name: α-D-mannoside mannohydrolase
Comments: Also hydrolyses α-D-lyxosides and heptopyranosides with the same configuration at C-2, C-3 and C-4 as mannose.
References:
1.  Li, Y.-T. Presence of α-D-mannosidic linkage in glycoproteins. Liberation of D-mannose from various glycoproteins by α-mannosidase isolated from jack bean meal. J. Biol. Chem. 241 (1966) 1010–1012. [PMID: 5905120]
2.  Winchester, B. Role of α-D-mannosidases in the biosynthesis and catabolism of glycoproteins. Biochem. Soc. Trans. 12 (1984) 522–524. [PMID: 6428944]
[EC 3.2.1.24 created 1961]
 
 
EC 4.2.3.186     Relevance: 22.1%
Accepted name: ent-13-epi-manoyl oxide synthase
Reaction: ent-8α-hydroxylabd-13-en-15-yl diphosphate = ent-13-epi-manoyl oxide + diphosphate
Glossary: Ent-13-epi-manoyl oxide = (13R)-ent-8,13-epoxylabd-14-ene
Other name(s): SmKSL2; ent-LDPP synthase
Systematic name: ent-8α-hydroxylabd-13-en-15-yl-diphosphate diphosphate-lyase (cyclizing, ent-13-epi-manoyl-oxide-forming)
Comments: Isolated from the plant Salvia miltiorrhiza (red sage).
References:
1.  Cui, G., Duan, L., Jin, B., Qian, J., Xue, Z., Shen, G., Snyder, J.H., Song, J., Chen, S., Huang, L., Peters, R.J. and Qi, X. Functional divergence of diterpene syntheses in the medicinal plant Salvia miltiorrhiza. Plant Physiol. 169 (2015) 1607–1618. [PMID: 26077765]
[EC 4.2.3.186 created 2017]
 
 
EC 5.5.1.28     Relevance: 22%
Accepted name: (–)-kolavenyl diphosphate synthase
Reaction: geranylgeranyl diphosphate = (–)-kolavenyl diphosphate
Glossary: (–)-kolavenyl diphosphate = (2E)-5-[(1R,2S,4aS,8aS)-1,2,4a,5-tetramethyl-1,2,3,4,4a,7,8,8a-octahydronaphthalen-1-yl]-3-methylpent-2-en-1-yl diposphate
Other name(s): SdKPS; TwTPS14; TwTPS10/KPS; SdCPS2; clerodienyl diphosphate synthase; CLPP
Systematic name: (–)-kolavenyl diphosphate lyase (ring-opening)
Comments: Isolated from the hallucinogenic plant Salvia divinorum (seer’s sage) and the medicinal plant Tripterygium wilfordii (thunder god vine).
References:
1.  Hansen, N.L., Heskes, A.M., Hamberger, B., Olsen, C.E., Hallstrom, B.M., Andersen-Ranberg, J. and Hamberger, B. The terpene synthase gene family in Tripterygium wilfordii harbors a labdane-type diterpene synthase among the monoterpene synthase TPS-b subfamily. Plant J. 89 (2017) 429–441. [PMID: 27801964]
2.  Chen, X., Berim, A., Dayan, F.E. and Gang, D.R. A (–)-kolavenyl diphosphate synthase catalyzes the first step of salvinorin A biosynthesis in Salvia divinorum. J. Exp. Bot. 68 (2017) 1109–1122. [PMID: 28204567]
[EC 5.5.1.28 created 2017]
 
 
EC 2.4.1.382     Relevance: 22%
Accepted name: CDP-abequose:α-L-Rha2OAc-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und α-1,3-abequosyltransferase
Reaction: CDP-α-D-abequose + 2-O-acetyl-α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = CDP + α-D-Abe-(1→3)-2-O-acetyl-α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und
Glossary: α-L-Rha2OAc-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = 2-O-acetyl-α-L-rhamnopyranosyl-(1→2)-α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
α-D-Abe-(1→3)-2-O-acetyl-α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = α-D-abequosyl-(1→3)-2-O-acetyl-α-L-rhamnopyranosyl-(1→2)-α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaR (gene name); rfbR (gene name)
Systematic name: CDP-α-D-abequose:2-O-acetyl-α-L-rhamnopyranosyl-(1→2)-α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 3IV-α-abequosyltransferase (configuration retaining)
Comments: The enzyme, present in Salmonella strains that belong to group C2, participates in the biosynthesis of the repeat unit of O antigens produced by these strains.
References:
1.  Liu, D., Lindqvist, L. and Reeves, P.R. Transferases of O-antigen biosynthesis in Salmonella enterica: dideoxyhexosyltransferases of groups B and C2 and acetyltransferase of group C2. J. Bacteriol. 177 (1995) 4084–4088. [PMID: 7541787]
2.  Zhao, X., Dai, Q., Jia, R., Zhu, D., Liu, M., Wang, M., Chen, S., Sun, K., Yang, Q., Wu, Y. and Cheng, A. two novel Salmonella bivalent vaccines confer dual protection against two Salmonella serovars in mice. Front Cell Infect Microbiol 7:391 (2017). [PMID: 28929089]
[EC 2.4.1.382 created 2021]
 
 
EC 2.1.1.294     Relevance: 21.9%
Accepted name: 3-O-phospho-polymannosyl GlcNAc-diphospho-ditrans,octacis-undecaprenol 3-phospho-methyltransferase
Reaction: S-adenosyl-L-methionine + 3-O-phospho-α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol = S-adenosyl-L-homocysteine + 3-O-methylphospho-α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbdD; S-adenosyl-L-methionine:3-O-phospho-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Man-(1→3)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-α-diphospho-ditrans,octacis-undecaprenol 3-phospho-methyltransferase
Systematic name: S-adenosyl-L-methionine:3-O-phospho-α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol 3-phospho-methyltransferase
Comments: The enzyme is involved in the biosynthesis of the polymannose O-polysaccharide in the outer leaflet of the membrane of Escherichia coli serotype O9a. O-Polysaccharide structures vary extensively because of differences in the number and type of sugars in the repeat unit. The dual kinase/methylase WbdD also catalyses the preceding phosphorylation of α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol (cf. EC 2.7.1.181, polymannosyl GlcNAc-diphospho-ditrans,octacis-undecaprenol kinase).
References:
1.  Clarke, B.R., Cuthbertson, L. and Whitfield, C. Nonreducing terminal modifications determine the chain length of polymannose O antigens of Escherichia coli and couple chain termination to polymer export via an ATP-binding cassette transporter. J. Biol. Chem. 279 (2004) 35709–35718. [PMID: 15184370]
2.  Clarke, B.R., Greenfield, L.K., Bouwman, C. and Whitfield, C. Coordination of polymerization, chain termination, and export in assembly of the Escherichia coli lipopolysaccharide O9a antigen in an ATP-binding cassette transporter-dependent pathway. J. Biol. Chem. 284 (2009) 30662–30672. [PMID: 19734145]
3.  Clarke, B.R., Richards, M.R., Greenfield, L.K., Hou, D., Lowary, T.L. and Whitfield, C. In vitro reconstruction of the chain termination reaction in biosynthesis of the Escherichia coli O9a O-polysaccharide: the chain-length regulator, WbdD, catalyzes the addition of methyl phosphate to the non-reducing terminus of the growing glycan. J. Biol. Chem. 286 (2011) 41391–41401. [PMID: 21990359]
4.  Liston, S.D., Clarke, B.R., Greenfield, L.K., Richards, M.R., Lowary, T.L. and Whitfield, C. Domain interactions control complex formation and polymerase specificity in the biosynthesis of the Escherichia coli O9a antigen. J. Biol. Chem. 290 (2015) 1075–1085. [PMID: 25422321]
[EC 2.1.1.294 created 2014, modified 2018]
 
 
EC 5.4.99.15     Relevance: 21.8%
Accepted name: (1→4)-α-D-glucan 1-α-D-glucosylmutase
Reaction: 4-[(1→4)-α-D-glucosyl]n-1-D-glucose = 1-α-D-[(1→4)-α-D-glucosyl]n-1-α-D-glucopyranoside
Other name(s): malto-oligosyltrehalose synthase; maltodextrin α-D-glucosyltransferase
Systematic name: (1→4)-α-D-glucan 1-α-D-glucosylmutase
Comments: The enzyme from Arthrobacter sp., Sulfolobus acidocaldarius acts on (1→4)-α-D-glucans containing three or more (1→4)-α-linked D-glucose units. Not active towards maltose.
References:
1.  Maruta, K., Nakada, T., Kubota, M., Chaen, H., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Formation of trehalose from maltooligosaccharides by a novel enzymatic system. Biosci. Biotechnol. Biochem. 59 (1995) 1829–1834. [PMID: 8534970]
2.  Nakada, T., Maruta, K., Tsusaki, K., Kubota, M., Chaen, H., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Purification and properties of a novel enzyme, maltooligosyl trehalose synthase, from Arthrobacter sp. Q36. Biosci. Biotechnol. Biochem. 59 (1995) 2210–2214. [PMID: 8611744]
3.  Nakada, T., Ikegami, S., Chaen, H., Kubota, M., Fukuda, S., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Purification and characterization of thermostable maltooligosyl trehalose synthase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius. Biosci. Biotechnol. Biochem. 60 (1996) 263–266. [PMID: 9063973]
[EC 5.4.99.15 created 1999]
 
 
EC 2.4.1.380     Relevance: 21.5%
Accepted name: GDP-Man:α-D-Man-(1→3)-α-D-Gal diphosphoundecaprenol α-1,2-mannosyltransferase
Reaction: GDP-α-D-mannose + α-D-Man-(1→3)-α-D-Gal-PP-Und = GDP + α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und
Glossary: α-D-Man-(1→3)-α-D-Gal-PP-Und = α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaW (gene name); rfbW (gene name)
Systematic name: GDP-α-D-mannose:α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 2II-α-mannosyltransferase (configuration-retaining)
Comments: The enzyme, present in Salmonella strains that belong to group C2, participates in the biosynthesis of the repeat unit of O antigens produced by these strains.
References:
1.  Brown, P.K., Romana, L.K. and Reeves, P.R. Cloning of the rfb gene cluster of a group C2 Salmonella strain: comparison with the rfb regions of groups B and D. Mol. Microbiol. 5 (1991) 1873–1881. [PMID: 1722557]
2.  Brown, P.K., Romana, L.K. and Reeves, P.R. Molecular analysis of the rfb gene cluster of Salmonella serovar muenchen (strain M67): the genetic basis of the polymorphism between groups C2 and B. Mol. Microbiol. 6 (1992) 1385–1394. [PMID: 1379320]
3.  Liu, D., Haase, A.M., Lindqvist, L., Lindberg, A.A. and Reeves, P.R. Glycosyl transferases of O-antigen biosynthesis in Salmonella enterica: identification and characterization of transferase genes of groups B, C2, and E1. J. Bacteriol. 175 (1993) 3408–3413. [PMID: 7684736]
4.  Zhao, X., Dai, Q., Jia, R., Zhu, D., Liu, M., Wang, M., Chen, S., Sun, K., Yang, Q., Wu, Y. and Cheng, A. two novel Salmonella bivalent vaccines confer dual protection against two Salmonella serovars in mice. Front Cell Infect Microbiol 7:391 (2017). [PMID: 28929089]
[EC 2.4.1.380 created 2021]
 
 
EC 2.4.1.138     Relevance: 21.5%
Accepted name: mannotetraose 2-α-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-D-Man = UDP + α-D-Man-(1→3)-[α-D-GlcNAc-(1→2)]-α-D-Man-(1→2)-α-D-Man-(1→2)-D-Man
Other name(s): α-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine mannoside α1→2-αcetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:mannotetraose α-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:α-D-mannosyl-(1→3)-α-D-mannosyl-(1→2)-α-D-mannosyl-(1→2)-D-mannose α-N-acetyl-D-glucosaminyltransferase (configuration-retaining)
References:
1.  Douglas, R.H. and Ballou, C.E. Purification of an α-N-acetylglucosaminyltransferase from the yeast Kluyveromyces lactis and a study of mutants defective in this enzyme activity. Biochemistry 21 (1982) 1561–1570. [PMID: 6211189]
[EC 2.4.1.138 created 1984]
 
 
EC 2.7.8.32     Relevance: 21.4%
Accepted name: 3-O-α-D-mannopyranosyl-α-D-mannopyranose xylosylphosphotransferase
Reaction: UDP-xylose + 3-O-α-D-mannopyranosyl-α-D-mannopyranose = UMP + 3-O-(6-O-α-D-xylosylphospho-α-D-mannopyranosyl)-α-D-mannopyranose
Glossary: O-α-D-xylosylphospho-α-D-mannopyranosyl)-α-D-mannopyranose = O-α-D-xylosylphosphono-α-D-mannopyranosyl)-α-D-mannopyranose
Other name(s): XPT1
Systematic name: UDP-D-xylose:3-O-α-D-mannopyranosyl-α-D-mannopyranose xylosylphosphotransferase
Comments: Mn2+ required for activity. The enzyme is specific for mannose as an acceptor but is flexible as to the structural context of the mannosyl disaccharide.
References:
1.  Reilly, M.C., Levery, S.B., Castle, S.A., Klutts, J.S. and Doering, T.L. A novel xylosylphosphotransferase activity discovered in Cryptococcus neoformans. J. Biol. Chem. 284 (2009) 36118–36127. [PMID: 19864415]
[EC 2.7.8.32 created 2011]
 
 
EC 2.4.1.381     Relevance: 21.4%
Accepted name: dTDP-Rha:α-D-Man-(1→3)-α-D-Gal diphosphoundecaprenol α-1,2-rhamnosyltransferase
Reaction: dTDP-β-L-rhamnose + α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = dTDP + α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und
Glossary: α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
α-L-Rha-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Gal-PP-Und = α-L-rhamnopyranosyl-(1→2)-α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaQ (gene name); rfbQ (gene name)
Systematic name: dTDP-β-L-rhamnose:α-D-mannopyranosyl-(1→2)-α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 2III-α-rhamnosyltransferase (configuration-inverting)
Comments: The enzyme, present in Salmonella strains that belong to group C2, participates in the biosynthesis of the repeat unit of O antigens produced by these strains.
References:
1.  Brown, P.K., Romana, L.K. and Reeves, P.R. Cloning of the rfb gene cluster of a group C2 Salmonella strain: comparison with the rfb regions of groups B and D. Mol. Microbiol. 5 (1991) 1873–1881. [PMID: 1722557]
2.  Brown, P.K., Romana, L.K. and Reeves, P.R. Molecular analysis of the rfb gene cluster of Salmonella serovar muenchen (strain M67): the genetic basis of the polymorphism between groups C2 and B. Mol. Microbiol. 6 (1992) 1385–1394. [PMID: 1379320]
3.  Liu, D., Haase, A.M., Lindqvist, L., Lindberg, A.A. and Reeves, P.R. Glycosyl transferases of O-antigen biosynthesis in Salmonella enterica: identification and characterization of transferase genes of groups B, C2, and E1. J. Bacteriol. 175 (1993) 3408–3413. [PMID: 7684736]
4.  Zhao, X., Dai, Q., Jia, R., Zhu, D., Liu, M., Wang, M., Chen, S., Sun, K., Yang, Q., Wu, Y. and Cheng, A. two novel Salmonella bivalent vaccines confer dual protection against two Salmonella serovars in mice. Front Cell Infect Microbiol 7:391 (2017). [PMID: 28929089]
[EC 2.4.1.381 created 2021]
 
 
EC 3.2.1.198     Relevance: 21.4%
Accepted name: α-mannan endo-1,2-α-mannanase
Reaction: Hydrolysis of the terminal α-D-mannosyl-(1→3)-α-D-mannose disaccharide from α-D-mannosyl-(1→3)-α-D-mannosyl-(1→2)-α-D-mannosyl-(1→2)-α-D-mannosyl side chains in fungal cell wall α-mannans.
Systematic name: α-mannan 1,2-[α-D-mannosyl-(1→3)-α-D-mannose] hydrolase
Comments: The enzyme, characterized from the gut bacteria Bacteroides thetaiotaomicron and Bacteroides xylanisolvens, can also catalyse the reaction of EC 3.2.1.130, glycoprotein endo-α-1,2-mannosidase.
References:
1.  Hakki, Z., Thompson, A.J., Bellmaine, S., Speciale, G., Davies, G.J. and Williams, S.J. Structural and kinetic dissection of the endo-α-1,2-mannanase activity of bacterial GH99 glycoside hydrolases from Bacteroides spp. Chemistry 21 (2015) 1966–1977. [PMID: 25487964]
2.  Cuskin, F., Lowe, E.C., Temple, M.J., Zhu, Y., Cameron, E.A., Pudlo, N.A., Porter, N.T., Urs, K., Thompson, A.J., Cartmell, A., Rogowski, A., Hamilton, B.S., Chen, R., Tolbert, T.J., Piens, K., Bracke, D., Vervecken, W., Hakki, Z., Speciale, G., Munoz-Munoz, J.L., Day, A., Pena, M.J., McLean, R., Suits, M.D., Boraston, A.B., Atherly, T., Ziemer, C.J., Williams, S.J., Davies, G.J., Abbott, D.W., Martens, E.C. and Gilbert, H.J. Human gut Bacteroidetes can utilize yeast mannan through a selfish mechanism. Nature 517 (2015) 165–169. [PMID: 25567280]
[EC 3.2.1.198 created 2016]
 
 
EC 2.4.1.24     Relevance: 21.2%
Accepted name: 1,4-α-glucan 6-α-glucosyltransferase
Reaction: Transfers an α-D-glucosyl residue in a (1→4)-α-D-glucan to the primary hydroxy group of glucose, free or combined in a (1→4)-α-D-glucan
Other name(s): oligoglucan-branching glycosyltransferase; 1,4-α-D-glucan 6-α-D-glucosyltransferase; T-enzyme; D-glucosyltransferase; 1,4-α-D-glucan:1,4-α-D-glucan(D-glucose) 6-α-D-glucosyltransferase
Systematic name: (1→4)-α-D-glucan:(1→4)-α-D-glucan(D-glucose) 6-α-D-glucosyltransferase
References:
1.  Abdullah, M. and Whelan, W.J. Synthesis of α-1:6-glucosidic linkages by a transglycosylase from potato. Biochem. J. 75 (1960) 12P.
2.  Barker, S.A. and Carrington, T.R. Studies of Aspergillus niger. Part II. Transglycosidation by Aspergillus niger. J. Chem. Soc. (Lond.) (1953) 3588–3593.
3.  Saroja, K., Venkataraman, R. and Giri, K.V. Transglucosidation in Penicillium chrysogenum Q-176. Isolation and identification of the oligosaccharide. Biochem. J. 60 (1955) 399–403. [PMID: 13239572]
[EC 2.4.1.24 created 1965]
 
 
EC 3.2.1.207     Relevance: 21.1%
Accepted name: mannosyl-oligosaccharide α-1,3-glucosidase
Reaction: (1) Glc2Man9GlcNAc2-[protein] + H2O = GlcMan9GlcNAc2-[protein] + β-D-glucopyranose
(2) GlcMan9GlcNAc2-[protein] + H2O = Man9GlcNAc2-[protein] + β-D-glucopyranose
Glossary: Glc2Man9GlcNAc2-[protein] = {α-D-Glc-(1→3)-α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-N-Asn-[protein]
GlcMan9GlcNAc2-[protein] = {α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-N-Asn-[protein]
Man9GlcNAc2-[protein] = {α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-N-Asn-[protein]
Other name(s): ER glucosidase II; α-glucosidase II; trimming glucosidase II; ROT2 (gene name); GTB1 (gene name); GANAB (gene name); PRKCSH (gene name)
Systematic name: Glc2Man9GlcNAc2-[protein] 3-α-glucohydrolase (configuration-inverting)
Comments: This eukaryotic enzyme cleaves off sequentially the two α-1,3-linked glucose residues from the Glc2Man9GlcNAc2 oligosaccharide precursor of immature N-glycosylated proteins.
References:
1.  Trombetta, E.S., Simons, J.F. and Helenius, A. Endoplasmic reticulum glucosidase II is composed of a catalytic subunit, conserved from yeast to mammals, and a tightly bound noncatalytic HDEL-containing subunit. J. Biol. Chem. 271 (1996) 27509–27516. [PMID: 8910335]
2.  Ziak, M., Meier, M., Etter, K.S. and Roth, J. Two isoforms of trimming glucosidase II exist in mammalian tissues and cell lines but not in yeast and insect cells. Biochem. Biophys. Res. Commun. 280 (2001) 363–367. [PMID: 11162524]
3.  Wilkinson, B.M., Purswani, J. and Stirling, C.J. Yeast GTB1 encodes a subunit of glucosidase II required for glycoprotein processing in the endoplasmic reticulum. J. Biol. Chem. 281 (2006) 6325–6333. [PMID: 16373354]
4.  Mora-Montes, H.M., Bates, S., Netea, M.G., Diaz-Jimenez, D.F., Lopez-Romero, E., Zinker, S., Ponce-Noyola, P., Kullberg, B.J., Brown, A.J., Odds, F.C., Flores-Carreon, A. and Gow, N.A. Endoplasmic reticulum α-glycosidases of Candida albicans are required for N glycosylation, cell wall integrity, and normal host-fungus interaction. Eukaryot Cell 6 (2007) 2184–2193. [PMID: 17933909]
[EC 3.2.1.207 created 2018]
 
 
EC 3.2.1.28     Relevance: 21.1%
Accepted name: α,α-trehalase
Reaction: α,α-trehalose + H2O = β-D-glucose + α-D-glucose
Other name(s): trehalase
Systematic name: α,α-trehalose glucohydrolase
Comments: The enzyme is an anomer-inverting glucosidase that catalyses the hydrolysis of the α-glucosidic O-linkage of α,α-trehalose, releasing initially equimolar amounts of α- and β-D-glucose. It is widely distributed in microorganisms, plants, invertebrates and vertebrates.
References:
1.  Myrbäck, K. and Örtenblad, B. Trehalose und Hefe. II. Trehalasewirkung von Hefepräparaten. Biochem. Z. 291 (1937) 61–69.
2.  Kalf, G.F. and Rieder, S.V. The preparation and properties of trehalase. J. Biol. Chem. 230 (1958) 691–698. [PMID: 13525386]
3.  Hehre, E.J., Sawai, T., Brewer, C.F., Nakano, M. and Kanda, T. Trehalase: stereocomplementary hydrolytic and glucosyl transfer reactions with α- and β-D-glucosyl fluoride. Biochemistry 21 (1982) 3090–3097. [PMID: 7104311]
4.  Mori, H., Lee, J.H., Okuyama, M., Nishimoto, M., Ohguchi, M., Kim, D., Kimura, A. and Chiba, S. Catalytic reaction mechanism based on α-secondary deuterium isotope effects in hydrolysis of trehalose by European honeybee trehalase. Biosci. Biotechnol. Biochem. 73 (2009) 2466–2473. [PMID: 19897915]
[EC 3.2.1.28 created 1961, modified 2012]
 
 
EC 1.14.13.104      
Transferred entry: (+)-menthofuran synthase. Now EC 1.14.14.143, (+)-menthofuran synthase
[EC 1.14.13.104 created 2008, deleted 2018]
 
 
EC 2.3.1.122     Relevance: 20.9%
Accepted name: trehalose O-mycolyltransferase
Reaction: 2 α,α-trehalose 6-mycolate = α,α-trehalose + α,α-trehalose 6,6′-bismycolate
Other name(s): α,α’-trehalose 6-monomycolate:α,α’-trehalose mycolyltransferase; α,α’-trehalose-6-mycolate:α,α’-trehalose-6-mycolate 6′-mycolyltransferase
Systematic name: α,α-trehalose-6-mycolate:α,α-trehalose-6-mycolate 6′-mycolyltransferase
Comments: Catalyses the exchange of mycolic acid between trehalose, trehalose mycolate and trehalose bismycolate. Trehalose 6-palmitate can also act as donor.
References:
1.  Sathyamoorthy, N. and Takayama, K. Purification and characterization of a novel mycolic acid exchange enzyme from Mycobacterium smegmatis. J. Biol. Chem. 262 (1987) 13417–13423. [PMID: 3654621]
[EC 2.3.1.122 created 1990]
 
 
EC 1.3.99.25     Relevance: 20.9%
Accepted name: carvone reductase
Reaction: (1) (+)-dihydrocarvone + acceptor = (–)-carvone + reduced acceptor
(2) (–)-isodihydrocarvone + acceptor = (+)-carvone + reduced acceptor
Glossary: (+)-dihydrocarvone = (1S,4R)-menth-8-en-2-one
(+)-isodihydrocarvone = (1S,4R)-menth-8-en-2-one
(–)-carvone = (4R)-mentha-1(6),8-dien-6-one = (5R)-2-methyl-5-(prop-1-en-2-yl)cyclohex-2-en-1-one
Systematic name: (+)-dihydrocarvone:acceptor 1,6-oxidoreductase
Comments: This enzyme participates in the carveol and dihydrocarveol degradation pathway of the Gram-positive bacterium Rhodococcus erythropolis DCL14. The enzyme has not been purified, and requires an unknown cofactor, which is different from NAD+, NADP+ or a flavin.
References:
1.  van der Werf, M.J. and Boot, A.M. Metabolism of carveol and dihydrocarveol in Rhodococcus erythropolis DCL14. Microbiology 146 (2000) 1129–1141. [PMID: 10832640]
[EC 1.3.99.25 created 2008]
 
 
EC 1.1.1.296     Relevance: 20.7%
Accepted name: dihydrocarveol dehydrogenase
Reaction: menth-8-en-2-ol + NAD+ = menth-8-en-2-one + NADH + H+
Glossary: (+)-dihydrocarveol = (1S,2S,4S)-menth-8-en-2-ol
(+)-isodihydrocarveol = (1S,2S,4R)-menth-8-en-2-ol
(+)-neoisodihydrocarveol = (1S,2R,4R)-menth-8-en-2-ol
(–)-dihydrocarvone = (1S,4S)-menth-8-en-2-one
(+)-isodihydrocarvone = (1S,4R)-menth-8-en-2-one
Other name(s): carveol dehydrogenase (ambiguous)
Systematic name: menth-8-en-2-ol:NAD+ oxidoreductase
Comments: This enzyme from the Gram-positive bacterium Rhodococcus erythropolis DCL14 forms part of the carveol and dihydrocarveol degradation pathway. The enzyme accepts all eight stereoisomers of menth-8-en-2-ol as substrate, although some isomers are converted faster than others. The preferred substrates are (+)-neoisodihydrocarveol, (+)-isodihydrocarveol, (+)-dihydrocarveol and (–)-isodihydrocarveol.
References:
1.  van der Werf, M.J. and Boot, A.M. Metabolism of carveol and dihydrocarveol in Rhodococcus erythropolis DCL14. Microbiology 146 (2000) 1129–1141. [PMID: 10832640]
[EC 1.1.1.296 created 2008]
 
 
EC 2.4.1.60     Relevance: 20.6%
Accepted name: CDP-abequose:α-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und α-1,3-abequosyltransferase
Reaction: CDP-α-D-abequose + α-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und = CDP + α-D-Abe-(1→3)-α-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und
Glossary: D-abequose = 3,6-deoxy-D-xylo-hexose = 3,6-deoxy-D-galactose = 3-deoxy-D-fucose
α-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und = α-D-mannopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
α-D-Abe-(1→3)-α-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und = α-D-abequopyranosyl-(1→3)-α-D-mannopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaV (gene name); rfbV (gene name); trihexose diphospholipid abequosyltransferase; abequosyltransferase (ambiguous); CDP-α-D-abequose:Man(α1→4)Rha(α1→3)Gal(β-1)-diphospholipid D-abequosyltransferase
Systematic name: CDP-α-D-abequose:α-D-mannopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 3III-α-abequosyltransferase (configuration retaining)
Comments: The enzyme from Salmonella participates in the biosynthesis of the repeat unit of O antigens produced by strains that belong to the A, B and D1-D3 groups. The enzyme is able to transfer abequose, paratose, or tyvelose, depending on the availability of the specific dideoxyhexose in a particular strain.
References:
1.  Osborn, M.J. and Weiner, I.M. Biosynthesis of a bacterial lipopolysaccharide. VI. Mechanism of incorporation of abequose into the O-antigen of Salmonella typhimurium. J. Biol. Chem. 243 (1968) 2631–2639. [PMID: 4297268]
2.  Liu, D., Lindqvist, L. and Reeves, P.R. Transferases of O-antigen biosynthesis in Salmonella enterica: dideoxyhexosyltransferases of groups B and C2 and acetyltransferase of group C2. J. Bacteriol. 177 (1995) 4084–4088. [PMID: 7541787]
[EC 2.4.1.60 created 1972, modified 2012, modified 2021]
 
 
EC 2.4.1.387     Relevance: 20.4%
Accepted name: isomaltosyltransferase
Reaction: (1) 2 α-isomaltosyl-(1→4)-maltotriose = α-isomaltosyl-(1→3)-α-isomaltosyl-(1→4)-maltotriose + maltotriose
(2) α-isomaltosyl-(1→3)-α-isomaltosyl-(1→4)-maltotriose = cyclobis-(1→6)-α-nigerosyl + maltotriose
Systematic name: α-isomaltosyl-(1→3)-1,4-α-D-glucan:1,4-α-D-glucan 3-α-isomaltosyltransferase
Comments: The enzyme, found in bacteria that produce cyclobis-(1→6)-α-nigerosyl, acts on the products of EC 2.4.1.24, 1,4-α-glucan 6-α;-glucosyltransferase. It catalyses the α-(1→3) transfer of the isomaltosyl moiety of one substrate to another, resulting in α-isomaltosyl-(1→3)-α-isomaltosyl-α-(1→4)-glucan formation. In addition, the enzyme catalyses the intramolecular cyclization of the product, eventually generating cyclobis-(1→6)-α-nigerosyl.
References:
1.  Aga, H., Maruta, K., Yamamoto, T., Kubota, M., Fukuda, S., Kurimoto, M. and Tsujisaka, Y. Cloning and sequencing of the genes encoding cyclic tetrasaccharide-synthesizing enzymes from Bacillus globisporus C11. Biosci. Biotechnol. Biochem. 66 (2002) 1057–1068. [PMID: 12092816]
2.  Nishimoto, T., Aga, H., Mukai, K., Hashimoto, T., Watanabe, H., Kubota, M., Fukuda, S., Kurimoto, M. and Tsujisaka, Y. Purification and characterization of glucosyltransferase and glucanotransferase involved in the production of cyclic tetrasaccharide in Bacillus globisporus C11. Biosci. Biotechnol. Biochem. 66 (2002) 1806–1818. [PMID: 12400677]
3.  Kim, Y.K., Kitaoka, M., Hayashi, K., Kim, C.H. and Cote, G.L. A synergistic reaction mechanism of a cycloalternan-forming enzyme and a D-glucosyltransferase for the production of cycloalternan in Bacillus sp. NRRL B-21195. Carbohydr. Res. 338 (2003) 2213–2220. [PMID: 14553982]
[EC 2.4.1.387 created 2022]
 
 
EC 3.2.1.130     Relevance: 20.4%
Accepted name: glycoprotein endo-α-1,2-mannosidase
Reaction: GlcMan9GlcNAc2-[protein] + H2O = Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,2) + α-D-glucosyl-(1→3)-α-D-mannopyranose
Glossary: GlcMan9GlcNAc2-[protein] = {α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein]
Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,2) = {α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein]
Other name(s): glucosylmannosidase; endo-α-D-mannosidase; endo-α-mannosidase; endomannosidase; glucosyl mannosidase; MANEA (gene name); glycoprotein glucosylmannohydrolase
Systematic name: glycoprotein glucosylmannohydrolase (configuration-retaining)
Comments: The enzyme catalyses the hydrolysis of the terminal α-D-glucosyl-(1→3)-D-mannosyl unit from the GlcMan9(GlcNAc)2 oligosaccharide component of N-glucosylated proteins during their processing in the Golgi apparatus. The name for the isomer is based on a nomenclature proposed by Prien et al [7].
References:
1.  Lubas, W.A. and Spiro, R.G. Golgi endo-α-D-mannosidase from rat liver, a novel N-linked carbohydrate unit processing enzyme. J. Biol. Chem. 262 (1987) 3775–3781. [PMID: 3818665]
2.  Tulsiani, D.R.P., Coleman, V.P. and Touster, O. Asparagine-linked glycoprotein biosynthesis in rat brain: identification of glucosidase I, glucosidase II, and endomannosidase (glucosyl mannosidase). Arch. Biochem. Biophys. 277 (1990) 114–121. [PMID: 2407194]
3.  Hiraizumi, S., Spohr, U. and Spiro, R.G. Ligand affinity chromatographic purification of rat liver Golgi endomannosidase. J. Biol. Chem. 269 (1994) 4697–4700. [PMID: 8106437]
4.  Spiro, M.J., Bhoyroo, V.D. and Spiro, R.G. Molecular cloning and expression of rat liver endo-α-mannosidase, an N-linked oligosaccharide processing enzyme. J. Biol. Chem. 272 (1997) 29356–29363. [PMID: 9361017]
5.  Hamilton, S.R., Li, H., Wischnewski, H., Prasad, A., Kerley-Hamilton, J.S., Mitchell, T., Walling, A.J., Davidson, R.C., Wildt, S. and Gerngross, T.U. Intact α-1,2-endomannosidase is a typical type II membrane protein. Glycobiology 15 (2005) 615–624. [PMID: 15677381]
6.  Hardt, B., Volker, C., Mundt, S., Salska-Navarro, M., Hauptmann, M. and Bause, E. Human endo-α1,2-mannosidase is a Golgi-resident type II membrane protein. Biochimie 87 (2005) 169–179. [PMID: 15760709]
7.  Prien, J.M., Ashline, D.J., Lapadula, A.J., Zhang, H. and Reinhold, V.N. The high mannose glycans from bovine ribonuclease B isomer characterization by ion trap MS. J. Am. Soc. Mass Spectrom. 20 (2009) 539–556. [PMID: 19181540]
[EC 3.2.1.130 created 1990, modified 2017]
 
 
EC 2.4.1.261     Relevance: 20.1%
Accepted name: dolichyl-P-Man:Man8GlcNAc2-PP-dolichol α-1,2-mannosyltransferase
Reaction: dolichyl β-D-mannosyl phosphate + α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol + dolichyl phosphate
Other name(s): ALG9; ALG9 α1,2 mannosyltransferase; dolichylphosphomannose-dependent ALG9 mannosyltransferase; ALG9 mannosyltransferase; Dol-P-Man:Man8GlcNAc2-PP-Dol α-1,2-mannosyltransferase; dolichyl β-D-mannosyl phosphate:D-Man-α-(1→2)-D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→6)]-D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol 2-α-D-mannosyltransferase
Systematic name: dolichyl β-D-mannosyl-phosphate:α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 2-α-D-mannosyltransferase (configuration-inverting)
Comments: The formation of N-glycosidic linkages of glycoproteins involves the ordered assembly of the common Glc3Man9GlcNAc2 core-oligosaccharide on the lipid carrier dolichyl diphosphate. Early mannosylation steps occur on the cytoplasmic side of the endoplasmic reticulum with GDP-Man as donor, the final reactions from Man5GlcNAc2-PP-Dol to Man9Glc-NAc2-PP-Dol on the lumenal side use dolichyl β-D-mannosyl phosphate. ALG9 mannosyltransferase catalyses the addition of two different α-1,2-mannose residues: the addition of α-1,2-mannose to Man6GlcNAc2-PP-Dol (EC 2.4.1.259) and the addition of α-1,2-mannose to Man8GlcNAc2-PP-Dol (EC 2.4.1.261).
References:
1.  Vleugels, W., Keldermans, L., Jaeken, J., Butters, T.D., Michalski, J.C., Matthijs, G. and Foulquier, F. Quality control of glycoproteins bearing truncated glycans in an ALG9-defective (CDG-IL) patient. Glycobiology 19 (2009) 910–917. [PMID: 19451548]
2.  Frank, C.G. and Aebi, M. ALG9 mannosyltransferase is involved in two different steps of lipid-linked oligosaccharide biosynthesis. Glycobiology 15 (2005) 1156–1163. [PMID: 15987956]
[EC 2.4.1.261 created 1976 as EC 2.4.1.130, part transferred 2011 to EC 2.4.1.261, modified 2012]
 
 
EC 3.2.1.106     Relevance: 20.1%
Accepted name: mannosyl-oligosaccharide glucosidase
Reaction: Glc3Man9GlcNAc2-[protein] + H2O = Glc2Man9GlcNAc2-[protein] + β-D-glucopyranose
Glossary: Glc3Man9GlcNAc2 = [α-D-Glc-(1→2)-α-D-Glc-(1→3)-α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-{α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)}-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc]-N-Asn-[protein]
Glc2Man9GlcNAc2-[protein] = [α-D-Glc-(1→3)-α-D-Glc-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-{α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)}-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc]-N-Asn-[protein]
Other name(s): Glc3Man9NAc2 oligosaccharide glucosidase; trimming glucosidase I; CWH41 (gene name); MOGS (gene name); mannosyl-oligosaccharide glucohydrolase
Systematic name: Glc3Man9GlcNAc2-[protein] glucohydrolase (configuration-inverting)
Comments: This enzyme catalyses the first step in the processing of the N-glycan tetradecasaccharide precursor Glc3Man9GlcNAc2, which takes place in the endoplasmic reticulum, by removing the distal α-1,2-linked glucose residue. This and subsequent processing steps are required before complex N-glycans can be synthesized.
References:
1.  Elting, J.J., Chen, W.W. and Lennarz, J. Characterization of a glucosidase involved in an initial step in the processing of oligosaccharide chains. J. Biol. Chem. 255 (1980) 2325–2331. [PMID: 7358674]
2.  Grinna, L.S. and Robbins, P.W. Glycoprotein biosynthesis. Rat liver microsomal glucosidases which process oligosaccharides. J. Biol. Chem. 254 (1979) 8814–8818. [PMID: 479161]
3.  Kilker, R.D., Saunier, B., Tkacz, J.S. and Herscovics, A. Partial purification from Saccharomyces cerevisiae of a soluble glucosidase which removes the terminal glucose from the oligosaccharide Glc3Man9GlcNAc2. J. Biol. Chem. 256 (1981) 5299–5603. [PMID: 7014569]
4.  Grinna, L.S. and Robbins, P.W. Substrate specificities of rat liver microsomal glucosidases which process glycoproteins. J. Biol. Chem. 255 (1980) 2255–2258. [PMID: 7358666]
5.  Mark, M.J. and Kornfeld, S. Partial purification and characterization of the glucosidases involved in the processing of asparagine-linked oligosaccharides. Arch. Biochem. Biophys. 199 (1980) 249–258. [PMID: 7356331]
[EC 3.2.1.106 created 1984, modified 2018]
 
 
EC 2.4.1.383     Relevance: 20.1%
Accepted name: GDP-Man:α-L-Rha-(1→3)-α-D-Gal-PP-Und β-1,4-mannosyltransferase
Reaction: GDP-α-D-mannose + α-L-Rha-(1→3)-α-D-Gal-PP-Und = GDP + β-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und
Glossary: α-L-Rha-(1→3)-α-D-Gal-PP-Und = α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
β-D-Man-(1→4)-α-L-Rha-(1→3)-α-D-Gal-PP-Und = β-D-mannopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaO (gene name); rfbO (gene name)
Systematic name: GDP-α-D-mannose:α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 4II-β-mannosyltransferase (configuration inverting)
Comments: The enzyme participates in the biosynthesis of the O antigens produced by group E and D2 strains of the pathogenic bacterium Salmonella enterica.
References:
1.  Xiang, S.H., Hobbs, M. and Reeves, P.R. Molecular analysis of the rfb gene cluster of a group D2 Salmonella enterica strain: evidence for its origin from an insertion sequence-mediated recombination event between group E and D1 strains. J. Bacteriol. 176 (1994) 4357–4365. [PMID: 8021222]
2.  Zhao, Y., Biggins, J. B. and Thorson, J. S. Acceptor specificity of Salmonella GDP-Man:α-L-Rha-(1→3)-α-D- Gal- PP-Und β(1→4)-mannosyltransferase: A simplified assay based on unnatural acceptors. J. Am. Chem. Soc. 120 (1998) 12986–12987.
3.  Zhao, Y. and Thorson, J.S. Chemoenzymatic synthesis of the Salmonella group E1 core trisaccharide using a recombinant β-(1-→4)-mannosyltransferase. Carbohydr. Res. 319 (1999) 184–191. [PMID: 10520265]
[EC 2.4.1.383 created 2021]
 
 
EC 2.4.1.260     Relevance: 20.1%
Accepted name: dolichyl-P-Man:Man7GlcNAc2-PP-dolichol α-1,6-mannosyltransferase
Reaction: dolichyl β-D-mannosyl phosphate + α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Man-(1→6)]-β-D-Man-β-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = α-D-Man-α-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol + dolichyl phosphate
Other name(s): ALG12; ALG12 mannosyltransferase; ALG12 α1,6mannosyltransferase; dolichyl-P-mannose:Man7GlcNAc2-PP-dolichyl mannosyltransferase; dolichyl-P-Man:Man7GlcNAc2-PP-dolichyl α6-mannosyltransferase; EBS4; Dol-P-Man:Man7GlcNAc2-PP-Dol α-1,6-mannosyltransferase; dolichyl β-D-mannosyl phosphate:D-Man-α-(1→2)-D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→2)-D-Man-α-(1→3)-D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol α-1,6-mannosyltransferase
Systematic name: dolichyl β-D-mannosyl-phosphate:α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Man-(1→6)]-β-D-Man-β-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 6-α-D-mannosyltransferase (configuration-inverting)
Comments: The formation of N-glycosidic linkages of glycoproteins involves the ordered assembly of the common Glc3Man9GlcNAc2 core-oligosaccharide on the lipid carrier dolichyl diphosphate. Early mannosylation steps occur on the cytoplasmic side of the endoplasmic reticulum with GDP-Man as donor, the final reactions from Man5GlcNAc2-PP-Dol to Man9Glc-NAc2-PP-Dol on the lumenal side use dolichyl β-D-mannosyl phosphate.
References:
1.  Frank, C.G. and Aebi, M. ALG9 mannosyltransferase is involved in two different steps of lipid-linked oligosaccharide biosynthesis. Glycobiology 15 (2005) 1156–1163. [PMID: 15987956]
2.  Hong, Z., Jin, H., Fitchette, A.C., Xia, Y., Monk, A.M., Faye, L. and Li, J. Mutations of an α1,6 mannosyltransferase inhibit endoplasmic reticulum-associated degradation of defective brassinosteroid receptors in Arabidopsis. Plant Cell 21 (2009) 3792–3802. [PMID: 20023196]
3.  Cipollo, J.F. and Trimble, R.B. The Saccharomyces cerevisiae alg12δ mutant reveals a role for the middle-arm α1,2Man- and upper-arm α1,2Manα1,6Man- residues of Glc3Man9GlcNAc2-PP-Dol in regulating glycoprotein glycan processing in the endoplasmic reticulum and Golgi apparatus. Glycobiology 12 (2002) 749–762. [PMID: 12460943]
4.  Grubenmann, C.E., Frank, C.G., Kjaergaard, S., Berger, E.G., Aebi, M. and Hennet, T. ALG12 mannosyltransferase defect in congenital disorder of glycosylation type lg. Hum. Mol. Genet. 11 (2002) 2331–2339. [PMID: 12217961]
[EC 2.4.1.260 created 1976 as EC 2.4.1.130, part transferred 2011 to EC 2.4.1.160, modified 2012]
 
 
EC 1.23.1.3     Relevance: 20%
Accepted name: (–)-pinoresinol reductase
Reaction: (–)-lariciresinol + NADP+ = (–)-pinoresinol + NADPH + H+
Glossary: (–)-lariciresinol = 4-[(2R,3S,4S)-4-[(4-hydroxy-3-methoxyphenyl)methyl]-3-(hydroxymethyl)oxolan-2-yl]-2-methoxyphenol
(–)-pinoresinol = (1R,3aS,4R,6aS)-4,4′-(tetrahydro-1H,3H-furo[3,4-c]furan-1,4-diyl)bis(2-methoxyphenol)
Other name(s): pinoresinol/lariciresinol reductase; pinoresinol-lariciresinol reductases; (–)-pinoresinol-(–)-lariciresinol reductase; PLR
Systematic name: (–)-lariciresinol:NADP+ oxidoreductase
Comments: The reaction is catalysed in vivo in the opposite direction to that shown. A multifunctional enzyme that usually further reduces the product to (+)-secoisolariciresinol [EC 1.23.1.4, (–)-lariciresinol reductase]. Isolated from the plants Thuja plicata (western red cedar) [1], Linum perenne (perennial flax) [2] and Arabidopsis thaliana (thale cress) [3].
References:
1.  Fujita, M., Gang, D.R., Davin, L.B. and Lewis, N.G. Recombinant pinoresinol-lariciresinol reductases from western red cedar (Thuja plicata) catalyze opposite enantiospecific conversions. J. Biol. Chem. 274 (1999) 618–627. [PMID: 9872995]
2.  Hemmati, S., Schmidt, T.J. and Fuss, E. (+)-Pinoresinol/(-)-lariciresinol reductase from Linum perenne Himmelszelt involved in the biosynthesis of justicidin B. FEBS Lett. 581 (2007) 603–610. [PMID: 17257599]
3.  Nakatsubo, T., Mizutani, M., Suzuki, S., Hattori, T. and Umezawa, T. Characterization of Arabidopsis thaliana pinoresinol reductase, a new type of enzyme involved in lignan biosynthesis. J. Biol. Chem. 283 (2008) 15550–15557. [PMID: 18347017]
[EC 1.23.1.3 created 2013]
 
 
EC 2.4.1.309     Relevance: 20%
Accepted name: UDP-Gal:α-L-Fuc-1,2-β-Gal-1,3-α-GalNAc-1,3-α-GalNAc-diphosphoundecaprenol α-1,3-galactosyltransferase
Reaction: UDP-α-D-galactose + α-L-Fuc-(1→2)-β-D-Gal-(1→3)-α-D-GalNAc-(1→3)-α-D-GalNAc-diphospho-ditrans,octacis-undecaprenol = UDP + α-D-Gal-(1→3)-(α-L-Fuc-(1→2))-β-D-Gal-(1→3)-α-D-GalNAc-(1→3)-α-D-GalNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbnI
Systematic name: UDP-α-D-galactose:α-L-Fuc-(1→2)-β-D-Gal-(1→3)-α-D-GalNAc-(1→3)-α-D-GalNAc-diphospho-ditrans,octacis-undecaprenol α-1,3-galactosyltransferase
Comments: The enzyme is involved in the the biosynthesis of the O-polysaccharide repeating unit of the bacterium Escherichia coli serotype O86.
References:
1.  Yi, W., Shao, J., Zhu, L., Li, M., Singh, M., Lu, Y., Lin, S., Li, H., Ryu, K., Shen, J., Guo, H., Yao, Q., Bush, C.A. and Wang, P.G. Escherichia coli O86 O-antigen biosynthetic gene cluster and stepwise enzymatic synthesis of human blood group B antigen tetrasaccharide. J. Am. Chem. Soc. 127 (2005) 2040–2041. [PMID: 15713070]
2.  Yi, W., Zhu, L., Guo, H., Li, M., Li, J. and Wang, P.G. Formation of a new O-polysaccharide in Escherichia coli O86 via disruption of a glycosyltransferase gene involved in O-unit assembly. Carbohydr. Res. 341 (2006) 2254–2260. [PMID: 16839526]
3.  Woodward, R., Yi, W., Li, L., Zhao, G., Eguchi, H., Sridhar, P.R., Guo, H., Song, J.K., Motari, E., Cai, L., Kelleher, P., Liu, X., Han, W., Zhang, W., Ding, Y., Li, M. and Wang, P.G. In vitro bacterial polysaccharide biosynthesis: defining the functions of Wzy and Wzz. Nat. Chem. Biol. 6 (2010) 418–423. [PMID: 20418877]
[EC 2.4.1.309 created 2013]
 
 
EC 5.4.99.66     Relevance: 19.9%
Accepted name: α-onocerin synthase
Reaction: pre-α-onocerin = α-onocerin
Glossary: α-onocerin = 8,14-secogammacera-8(26),14(27)-diene-3β,21α-diol
pre-α-onocerin = (21S)-21,22-epoxypolypoda-8(26)-13,17-trien-3β-ol
Other name(s): LCD
Systematic name: pre-α-onocerin mutase (cyclizing, α-onocerin-forming)
Comments: Isolated from the plant Lycopodium clavatum.
References:
1.  Araki, T., Saga, Y., Marugami, M., Otaka, J., Araya, H., Saito, K., Yamazaki, M., Suzuki, H. and Kushiro, T. Onocerin biosynthesis requires two highly dedicated triterpene cyclases in a fern Lycopodium clavatum. ChemBioChem 17 (2016) 288–290. [PMID: 26663356]
[EC 5.4.99.66 created 2017]
 
 
EC 3.2.1.55     Relevance: 19.9%
Accepted name: non-reducing end α-L-arabinofuranosidase
Reaction: Hydrolysis of terminal non-reducing α-L-arabinofuranoside residues in α-L-arabinosides.
Other name(s): arabinosidase (ambiguous); α-arabinosidase; α-L-arabinosidase; α-arabinofuranosidase; polysaccharide α-L-arabinofuranosidase; α-L-arabinofuranoside hydrolase; L-arabinosidase (ambiguous); α-L-arabinanase
Systematic name: α-L-arabinofuranoside non-reducing end α-L-arabinofuranosidase
Comments: The enzyme acts on α-L-arabinofuranosides, α-L-arabinans containing (1,3)- and/or (1,5)-linkages, arabinoxylans and arabinogalactans. Some β-galactosidases (EC 3.2.1.23) and β-D-fucosidases (EC 3.2.1.38) also hydrolyse α-L-arabinosides. cf. EC 3.2.1.185, non-reducing end β-L-arabinofuranosidase.
References:
1.  Tagawa, K. and Kaji, A. Preparation of L-arabinose-containing polysaccharides and the action of an α-L-arabinofuranosidase on these polysaccharides. Carbohydr. Res. 11 (1969) 293–301.
2.  Kaji, A. and Tagawa, K. Purification, crystallization and amino acid composition of α-L-arabinofuranosidase from Aspergillus niger. Biochim. Biophys. Acta 207 (1970) 456–464. [PMID: 5452669]
3.  Kaji, A. and Yoshihara, O. Properties of purified α-L-arabinofuranosidase from Corticium rolfsii. Biochim. Biophys. Acta 250 (1971) 367–371. [PMID: 5143344]
4.  Margolles-Clark, E., Tenkanen, M., Nakari-Setala, T. and Penttila, M. Cloning of genes encoding α-L-arabinofuranosidase and β-xylosidase from Trichoderma reesei by expression in Saccharomyces cerevisiae. Appl. Environ. Microbiol. 62 (1996) 3840–3846. [PMID: 8837440]
5.  Inacio, J.M., Correia, I.L. and de Sa-Nogueira, I. Two distinct arabinofuranosidases contribute to arabino-oligosaccharide degradation in Bacillus subtilis. Microbiology 154 (2008) 2719–2729. [PMID: 18757805]
[EC 3.2.1.55 created 1972, modified 1976 (EC 3.2.1.79 created 1972, incorporated 1976), modified 2013]
 
 
EC 2.4.1.125     Relevance: 19.9%
Accepted name: sucrose—1,6-α-glucan 3(6)-α-glucosyltransferase
Reaction: (1) sucrose + [(1→6)-α-D-glucosyl]n = D-fructose + [(1→6)-α-D-glucosyl]n+1
(2) sucrose + [(1→6)-α-D-glucosyl]n = D-fructose + (1→3)-α-D-glucosyl-[(1→6)-α-D-glucosyl]n
Other name(s): water-soluble-glucan synthase (misleading); GTF-I; GTF-S; GTF-SI; sucrose-1,6-α-glucan 3(6)-α-glucosyltransferase; sucrose:1,6-α-D-glucan 3-α- and 6-α-glucosyltransferase; sucrose:1,6-, 1,3-α-D-glucan 3-α- and 6-α-D-glucosyltransferase; sucrose:1,6-α-D-glucan 3(6)-α-D-glucosyltransferase; gtfB (gene name); gtfC (gene name); gtfD (gene name)
Systematic name: sucrose:(1→6)-α-D-glucan 3(6)-α-D-glucosyltransferase
Comments: The glucansucrases transfer a D-glucosyl residue from sucrose to a glucan chain. They are classified based on the linkage by which they attach the transferred residue. In some cases, in which the enzyme forms more than one linkage type, classification relies on the relative proportion of the linkages that are generated. This enzyme extends (1→6)-α-D-glucans by both α(1→3) and α(1→6) linkages, with one of the linkage types being dominant. cf. EC 2.4.1.140, alternansucrase.
References:
1.  Mukasa, H., Shimamura, A. and Tsumori, H. Purification and characterization of basic glucosyltransferase from Streptococcus mutans serotype c. Biochim. Biophys. Acta 719 (1982) 81–89. [PMID: 6216919]
2.  Shimamura, A., Tsumori, H. and Mukasa, H. Purification and properties of Streptococcus mutans extracellular glucosyltransferase. Biochim. Biophys. Acta 702 (1982) 72–80. [PMID: 6461359]
3.  Tsumori, H., Shimamura, A. and Mukasa, H. Purification and properties of extracellular glucosyltransferase synthesizing 1,6-, 1,3-α-D-glucan from Streptococcus mutans serotype a. J. Gen. Microbiol. 131 (1985) 3347–3353. [PMID: 2937877]
4.  Fujiwara, T., Tamesada, M., Bian, Z., Kawabata, S., Kimura, S. and Hamada, S. Deletion and reintroduction of glucosyltransferase genes of Streptococcus mutans and role of their gene products in sucrose dependent cellular adherence. Microb Pathog 20 (1996) 225–233. [PMID: 8737492]
5.  Monchois, V., Willemot, R.M. and Monsan, P. Glucansucrases: mechanism of action and structure-function relationships. FEMS Microbiol. Rev. 23 (1999) 131–151. [PMID: 10234842]
6.  Ito, K., Ito, S., Shimamura, T., Weyand, S., Kawarasaki, Y., Misaka, T., Abe, K., Kobayashi, T., Cameron, A.D. and Iwata, S. Crystal structure of glucansucrase from the dental caries pathogen Streptococcus mutans. J. Mol. Biol. 408 (2011) 177–186. [PMID: 21354427]
[EC 2.4.1.125 created 1984]
 
 
EC 3.2.1.141     Relevance: 19.9%
Accepted name: 4-α-D-{(1→4)-α-D-glucano}trehalose trehalohydrolase
Reaction: hydrolysis of (1→4)-α-D-glucosidic linkage in 4-α-D-[(1→4)-α-D-glucanosyl]n trehalose to yield trehalose and (1→4)-α-D-glucan
Other name(s): malto-oligosyltrehalose trehalohydrolase
Systematic name: 4-α-D-[(1→4)-α-D-glucano]trehalose glucanohydrolase (trehalose-producing)
References:
1.  Maruta, K., Nakada, T., Kubota, M., Chaen, H., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Formation of trehalose from maltooligosaccharides by a novel enzymatic system. Biosci. Biotechnol. Biochem. 59 (1995) 1829–1834. [PMID: 8534970]
2.  Nakada, T., Maruta, K., Mitsuzumi, H., Kubota, M., Chaen, H., Sugimoto, T. , Kurimoto M., Tsujisaka, Y. Purification and characterization of a novel enzyme, maltooligosyl trehalose trehalohydrolase, from Arthrobacter sp. Q36. Biosci. Biotechnol. Biochem. 59 (1995) 2215–2218. [PMID: 8611745]
3.  Nakada, T., Ikegami, S., Chaen, H., Kubota, M., Fukuda, S., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Purification and characterization of thermostable maltooligosyl trehalose trehalohydrolase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius. Biosci. Biotechnol. Biochem. 60 (1996) 267–270. [PMID: 9063974]
[EC 3.2.1.141 created 1999]
 
 
EC 2.4.1.231     Relevance: 19.8%
Accepted name: α,α-trehalose phosphorylase (configuration-retaining)
Reaction: α,α-trehalose + phosphate = α-D-glucose + α-D-glucose 1-phosphate
Other name(s): trehalose phosphorylase[ambiguous]
Systematic name: α,α-trehalose:phosphate α-D-glucosyltransferase
Comments: Unlike EC 2.4.1.64, α,α-trehalose phosphorylase, this enzyme retains its anomeric configuration. Vanadate is a strong competitive inhibitor of this reversible reaction.
References:
1.  Eis, C. and Nidetzky, B. Substrate-binding recognition and specificity of trehalose phosphorylase from Schizophyllum commune examined in steady-state kinetic studies with deoxy and deoxyfluoro substrate analogues and inhibitors. Biochem. J. 363 (2002) 335–340. [PMID: 11931662]
2.  Eis, C., Watkins, M., Prohaska, T. and Nidetzky, B. Fungal trehalose phosphorylase: kinetic mechanism, pH-dependence of the reaction and some structural properties of the enzyme from Schizophyllum commune. Biochem. J. 356 (2001) 757–767. [PMID: 11389683]
3.  Nidetzky, B. and Eis, C. α-Retaining glucosyl transfer catalysed by trehalose phosphorylase from Schizophyllum commune: mechanistic evidence obtained from steady-state kinetic studies with substrate analogues and inhibitors. Biochem. J. 360 (2001) 727–736. [PMID: 11736665]
[EC 2.4.1.231 created 2003]
 
 
EC 3.2.1.22     Relevance: 19.8%
Accepted name: α-galactosidase
Reaction: Hydrolysis of terminal, non-reducing α-D-galactose residues in α-D-galactosides, including galactose oligosaccharides, galactomannans and galactolipids
Other name(s): melibiase; α-D-galactosidase; α-galactosidase A; α-galactoside galactohydrolase
Systematic name: α-D-galactoside galactohydrolase
Comments: Also hydrolyses α-D-fucosides.
References:
1.  Suzuki, H., Li, S.-C. and Li, Y.-T. α-Galactosidase from Mortierella vinacea. Crystallization and properties. J. Biol. Chem. 245 (1970) 781–786. [PMID: 5418105]
2.  Wiederschain, G. and Beyer, E. [Interrelation of α-D-fucosidase and α-D-galactosidase activities in man and animals] Dokl. Akad. Nauk S.S.S.R. 231 (1976) 486–488. [PMID: 976079]
[EC 3.2.1.22 created 1961]
 
 
EC 1.14.13.47      
Transferred entry: (S)-limonene 3-monooxygenase. Now EC 1.14.14.99, (S)-limonene 3-monooxygenase
[EC 1.14.13.47 created 1992, modified 2003, deleted 2018]
 
 
EC 2.4.1.379     Relevance: 19.6%
Accepted name: GDP-Man:α-D-Gal-diphosphoundecaprenol α-1,3-mannosyltransferase
Reaction: GDP-α-D-mannose + α-D-galactosyl-diphospho-ditrans-octacis-undecaprenol = GDP + α-D-Man-(1→3)-α-D-Gal-PP-Und
Glossary: α-D-Man-(1→3)-α-D-Gal-PP-Und = α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaZ (gene name); rfbZ (gene name)
Systematic name: GDP-α-D-mannose:α-D-mannopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol 3-α-mannosyltransferase (configuration-retaining)
Comments: The enzyme, present in Salmonella strains that belong to group C2, participates in the biosynthesis of the repeat unit of O antigens produced by these strains.
References:
1.  Brown, P.K., Romana, L.K. and Reeves, P.R. Cloning of the rfb gene cluster of a group C2 Salmonella strain: comparison with the rfb regions of groups B and D. Mol. Microbiol. 5 (1991) 1873–1881. [PMID: 1722557]
2.  Brown, P.K., Romana, L.K. and Reeves, P.R. Molecular analysis of the rfb gene cluster of Salmonella serovar muenchen (strain M67): the genetic basis of the polymorphism between groups C2 and B. Mol. Microbiol. 6 (1992) 1385–1394. [PMID: 1379320]
3.  Liu, D., Haase, A.M., Lindqvist, L., Lindberg, A.A. and Reeves, P.R. Glycosyl transferases of O-antigen biosynthesis in Salmonella enterica: identification and characterization of transferase genes of groups B, C2, and E1. J. Bacteriol. 175 (1993) 3408–3413. [PMID: 7684736]
4.  Zhao, X., Dai, Q., Jia, R., Zhu, D., Liu, M., Wang, M., Chen, S., Sun, K., Yang, Q., Wu, Y. and Cheng, A. two novel Salmonella bivalent vaccines confer dual protection against two Salmonella serovars in mice. Front Cell Infect Microbiol 7:391 (2017). [PMID: 28929089]
[EC 2.4.1.379 created 2021]
 
 
EC 2.4.1.342     Relevance: 19.6%
Accepted name: α-maltose-1-phosphate synthase
Reaction: ADP-α-D-glucose + α-D-glucose-1-phosphate = ADP + α-maltose-1-phosphate
Glossary: maltose = α-D-glucopyranosyl-(1→4)-D-glucose
Other name(s): glgM (gene name)
Systematic name: ADP-α-D-glucose:α-D-glucose-1-phosphate 4-α-D-glucosyltransferase (configuration-retaining)
Comments: The enzyme, found in Mycobacteria, can also use UDP-α-D-glucose with much lower catalytic efficiency.
References:
1.  Koliwer-Brandl, H., Syson, K., van de Weerd, R., Chandra, G., Appelmelk, B., Alber, M., Ioerger, T.R., Jacobs, W.R., Jr., Geurtsen, J., Bornemann, S. and Kalscheuer, R. Metabolic network for the biosynthesis of intra- and extracellular α-glucans required for virulence of Mycobacterium tuberculosis. PLoS Pathog. 12 (2016) e1005768. [PMID: 27513637]
[EC 2.4.1.342 created 2016]
 
 
EC 3.2.1.133     Relevance: 19.6%
Accepted name: glucan 1,4-α-maltohydrolase
Reaction: hydrolysis of (1→4)-α-D-glucosidic linkages in polysaccharides so as to remove successive α-maltose residues from the non-reducing ends of the chains
Other name(s): maltogenic α-amylase; 1,4-α-D-glucan α-maltohydrolase
Systematic name: 4-α-D-glucan α-maltohydrolase
Comments: Acts on starch and related polysaccharides and oligosaccharides. The product is α-maltose; cf. EC 3.2.1.2 β-amylase.
References:
1.  Diderichsen, B. and Christiansen, L. Cloning of a maltogenic α-amylase from Bacillus stearothermophilus. FEMS Microbiol. Lett. 56 (1988) 53–59.
2.  Outtrup, H. and Norman, B.E. Properties and application of a thermostable maltogenic amylase produced by a strain of Bacillus modified by recombinant-DNA techniques. Stärke 36 (1984) 405–411.
[EC 3.2.1.133 created 1992, modified 1999]
 
 
EC 2.8.2.37     Relevance: 19.6%
Accepted name: trehalose 2-sulfotransferase
Reaction: 3′-phosphoadenylyl sulfate + α,α-trehalose = adenosine 3′,5′-bisphosphate + 2-O-sulfo-α,α-trehalose
Glossary: 2-O-sulfo-α,α-trehalose = trehalose 2-sulfate = α-D-glucopyranosyl 2-O-sulfo-α-D-glucopyranoside
Other name(s): Stf0 sulfotransferase; 3′-phosphoadenylyl-sulfate:α,α-trehalose 2-sulfotransferase
Systematic name: 3′-phosphoadenylyl-sulfate:α,α-trehalose 2-sulfonotransferase
Comments: The sulfation of trehalose in the bacterium Mycobacterium tuberculosis is required for the biosynthesis of sulfolipid-1.
References:
1.  Mougous, J.D., Petzold, C.J., Senaratne, R.H., Lee, D.H., Akey, D.L., Lin, F.L., Munchel, S.E., Pratt, M.R., Riley, L.W., Leary, J.A., Berger, J.M. and Bertozzi, C.R. Identification, function and structure of the mycobacterial sulfotransferase that initiates sulfolipid-1 biosynthesis. Nat. Struct. Mol. Biol. 11 (2004) 721–729. [PMID: 15258569]
2.  Pi, N., Hoang, M.B., Gao, H., Mougous, J.D., Bertozzi, C.R. and Leary, J.A. Kinetic measurements and mechanism determination of Stf0 sulfotransferase using mass spectrometry. Anal. Biochem. 341 (2005) 94–104. [PMID: 15866533]
[EC 2.8.2.37 created 2014]
 
 
EC 3.1.1.83     Relevance: 19.6%
Accepted name: monoterpene ε-lactone hydrolase
Reaction: (1) isoprop(en)ylmethyloxepan-2-one + H2O = 6-hydroxyisoprop(en)ylmethylhexanoate (general reaction)
(2) 4-isopropenyl-7-methyloxepan-2-one + H2O = 6-hydroxy-3-isopropenylheptanoate
(3) 7-isopropyl-4-methyloxepan-2-one + H2O = 6-hydroxy-3,7-dimethyloctanoate
Other name(s): MLH
Systematic name: isoprop(en)ylmethyloxepan-2-one lactonohydrolase
Comments: The enzyme catalyses the ring opening of ε-lactones which are formed during degradation of dihydrocarveol by the Gram-positive bacterium Rhodococcus erythropolis DCL14. The enzyme also acts on ethyl caproate, indicating that it is an esterase with a preference for lactones (internal cyclic esters). The enzyme is not stereoselective.
References:
1.  van der Vlugt-Bergmans , C.J. and van der Werf , M.J. Genetic and biochemical characterization of a novel monoterpene ε-lactone hydrolase from Rhodococcus erythropolis DCL14. Appl. Environ. Microbiol. 67 (2001) 733–741. [PMID: 11157238]
[EC 3.1.1.83 created 2008]
 
 
EC 1.14.13.48      
Transferred entry: (S)-limonene 6-monooxygenase. Now classified as EC 1.14.14.51, (S)-limonene 6-monooxygenase
[EC 1.14.13.48 created 1992, modified 2003, deleted 2017]
 
 
EC 2.4.1.167     Relevance: 19.4%
Accepted name: sucrose 6F-α-galactosyltransferase
Reaction: UDP-α-D-galactose + sucrose = UDP + 6F-α-D-galactosylsucrose
Other name(s): uridine diphosphogalactose-sucrose 6F-α-galactosyltransferase; UDPgalactose:sucrose 6fru-α-galactosyltransferase; sucrose 6F-α-galactotransferase; UDP-galactose:sucrose 6F-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:sucrose 6F-α-D-galactosyltransferase
Comments: The enzyme is involved in the synthesis of the trisaccharide planteose and higher analogues in the seeds of Plantago and Sesamum species.
References:
1.  Hopf, H., Spanfelner, M. and Kandler, O. Planteose synthesis in seeds of Sesamum indicum L. Z. Pflanzenphysiol. 114 (1984) 485–492.
[EC 2.4.1.167 created 1989]
 
 
EC 2.4.1.362     Relevance: 19.3%
Accepted name: α-(1→3) branching sucrase
Reaction: sucrose + a (1→6)-α-D-glucan = D-fructose + a (1→6)-α-D-glucan containing a (1→3)-α-D-glucose branch
Other name(s): branching sucrase A; BRS-A; brsA (gene name)
Systematic name: sucrose:(1→6)-α-D-glucan 3-α-D-[(1→3)-α-D-glucosyl]-transferase
Comments: The enzyme from Leuconostoc spp. is responsible for producing α-(1→3) branches in α-(1→6) glucans by transferring the glucose residue from fructose to a 3-hydroxyl group of a glucan.
References:
1.  Vuillemin, M., Claverie, M., Brison, Y., Severac, E., Bondy, P., Morel, S., Monsan, P., Moulis, C. and Remaud-Simeon, M. Characterization of the first α-(1→3) branching sucrases of the GH70 family. J. Biol. Chem. 291 (2016) 7687–7702. [PMID: 26763236]
2.  Moulis, C., Andre, I. and Remaud-Simeon, M. GH13 amylosucrases and GH70 branching sucrases, atypical enzymes in their respective families. Cell. Mol. Life Sci. 73 (2016) 2661–2679. [PMID: 27141938]
[EC 2.4.1.362 created 2019]
 
 
EC 3.2.1.139     Relevance: 19.2%
Accepted name: α-glucuronidase
Reaction: an α-D-glucuronoside + H2O = an alcohol + D-glucuronate
Other name(s): α-glucosiduronase
Systematic name: α-D-glucosiduronate glucuronohydrolase
Comments: Considerable differences in the specificities of the enzymes from different fungi for α-D-glucosiduronates have been reported. Activity is also found in the snail.
References:
1.  Puls, J. α-Glucuronidases in the hydrolysis of wood xylans. In: Visser, J., Kusters van Someren, M.A., Beldman, G. and Voragen, A.G.J. (Ed.), Xylans and Xylanases, Elsevier, Amsterdam, 1992, pp. 213–224.
2.  Uchida, H., Nanri, T., Kawabata, Y., Kusakabe, I., Murakami, K. Purification and characterization of intracellular α-glucuronidase from Aspergillus niger. Biosci. Biotechnol. Biochem. 56 (1992) 1608–1615.
[EC 3.2.1.139 created 1999]
 
 
EC 2.4.1.259     Relevance: 19.2%
Accepted name: dolichyl-P-Man:Man6GlcNAc2-PP-dolichol α-1,2-mannosyltransferase
Reaction: dolichyl β-D-mannosyl phosphate + α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→3)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol + dolichyl phosphate
Other name(s): ALG9; ALG9 α1,2 mannosyltransferase; dolichylphosphomannose-dependent ALG9 mannosyltransferase; ALG9 mannosyltransferase; Dol-P-Man:Man6GlcNAc2-PP-Dol α-1,2-mannosyltransferase; dolichyl β-D-mannosyl phosphate:D-Man-α-(1→2)-D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→3)-D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol α-1,2-mannosyltransferase
Systematic name: dolichyl β-D-mannosyl-phosphate:α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→3)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 2-α-D-mannosyltransferase (configuration-inverting)
Comments: The formation of N-glycosidic linkages of glycoproteins involves the ordered assembly of the common Glc3Man9GlcNAc2 core-oligosaccharide on the lipid carrier dolichyl diphosphate. Early mannosylation steps occur on the cytoplasmic side of the endoplasmic reticulum with GDP-Man as donor, the final reactions from Man5GlcNAc2-PP-Dol to Man9Glc-NAc2-PP-Dol on the lumenal side use dolichyl β-D-mannosyl phosphate. ALG9 mannosyltransferase catalyses the addition of two different α-1,2-mannose residues - the addition of α-1,2-mannose to Man6GlcNAc2-PP-Dol (EC 2.4.1.259) and the addition of α-1,2-mannose to Man8GlcNAc2-PP-Dol (EC 2.4.1.261).
References:
1.  Vleugels, W., Keldermans, L., Jaeken, J., Butters, T.D., Michalski, J.C., Matthijs, G. and Foulquier, F. Quality control of glycoproteins bearing truncated glycans in an ALG9-defective (CDG-IL) patient. Glycobiology 19 (2009) 910–917. [PMID: 19451548]
2.  Cipollo, J.F. and Trimble, R.B. The accumulation of Man(6)GlcNAc(2)-PP-dolichol in the Saccharomyces cerevisiae Δalg9 mutant reveals a regulatory role for the Alg3p α1,3-Man middle-arm addition in downstream oligosaccharide-lipid and glycoprotein glycan processing. J. Biol. Chem. 275 (2000) 4267–4277. [PMID: 10660594]
3.  Frank, C.G. and Aebi, M. ALG9 mannosyltransferase is involved in two different steps of lipid-linked oligosaccharide biosynthesis. Glycobiology 15 (2005) 1156–1163. [PMID: 15987956]
[EC 2.4.1.259 created 1976 as EC 2.4.1.130, part transferred 2011 to EC 2.4.1.259, modified 2012]
 
 
EC 1.14.13.49      
Transferred entry: (S)-limonene 7-monooxygenase. Now classified as EC 1.14.14.52, (S)-limonene 7-monooxygenase
[EC 1.14.13.49 created 1992, modified 2003, deleted 2017]
 
 
EC 3.2.1.50     Relevance: 19.2%
Accepted name: α-N-acetylglucosaminidase
Reaction: Hydrolysis of terminal non-reducing N-acetyl-D-glucosamine residues in N-acetyl-α-D-glucosaminides
Other name(s): α-acetylglucosaminidase; N-acetyl-α-D-glucosaminidase; N-acetyl-α-glucosaminidase; α-D-2-acetamido-2-deoxyglucosidase
Systematic name: α-N-acetyl-D-glucosaminide N-acetylglucosaminohydrolase
Comments: Hydrolyses UDP-N-acetylglucosamine.
References:
1.  von Figura, K. Human α-N-acetylglucosaminidase. 1. Purification and properties. Eur. J. Biochem. 80 (1977) 523–533. [PMID: 411658]
2.  von Figura, K. Human α-N-acetylglucosaminidase. 2. Activity towards natural substrates and multiple recognition forms. Eur. J. Biochem. 80 (1977) 535–542. [PMID: 923593]
3.  Weissmann, B., Rowen, G., Marshall, J. and Friederici, D. Mammalian α-acetylglucosaminidase. Enzymic properties, tissue distribution, and intracellular localization. Biochemistry 6 (1967) 207–214. [PMID: 4291567]
4.  Werries, E., Wollek, E., Gottschalk, A. and Buddecke, E. Separation of N-acetyl-α-glucosaminidase and N-acetyl-α-galactosaminidase from ox spleen. Cleavage of the O-glycosidic linkage between carbohydrate and polypeptide in ovine and bovine submaxillary glycoprotein by N-acetyl-α-galactosaminidase. Eur. J. Biochem. 10 (1969) 445–449. [PMID: 5348072]
[EC 3.2.1.50 created 1972]
 
 
EC 3.2.1.59     Relevance: 19%
Accepted name: glucan endo-1,3-α-glucosidase
Reaction: Endohydrolysis of (1→3)-α-D-glucosidic linkages in isolichenin, pseudonigeran and nigeran
Other name(s): endo-1,3-α-glucanase; mutanase; endo-(1→3)-α-glucanase; cariogenase; cariogenanase; endo-1,3-α-D-glucanase; 1,3(1,3;1,4)-α-D-glucan 3-glucanohydrolase
Systematic name: 3-α-D-glucan 3-glucanohydrolase
Comments: Products from pseudonigeran (1,3-α-D-glucan) are nigerose and α-D-glucose.
References:
1.  Hasegawa, S., Nordin, J.H. and Kirkwood, S. Enzymes that hydrolyze fungal cell wall polysaccharides. I. Purification and properties of an endo-α-D-(1-3)-glucanase from Trichoderma. J. Biol. Chem. 244 (1969) 5460–5470. [PMID: 5388595]
[EC 3.2.1.59 created 1972]
 
 
EC 3.2.1.49     Relevance: 18.9%
Accepted name: α-N-acetylgalactosaminidase
Reaction: Cleavage of non-reducing α-(1→3)-N-acetylgalactosamine residues from human blood group A and AB mucin glycoproteins, Forssman hapten and blood group A lacto series glycolipids
Other name(s): α-acetylgalactosaminidase; N-acetyl-α-D-galactosaminidase; N-acetyl-α-galactosaminidase; α-NAGAL; α-NAGA; α-GalNAcase
Systematic name: α-N-acetyl-D-galactosaminide N-acetylgalactosaminohydrolase
Comments: The human lysosomal enzyme is involved in the degradation of blood type A epitope.
References:
1.  Asfaw, B., Schindler, D., Ledvinova, J., Cerny, B., Smid, F. and Conzelmann, E. Degradation of blood group A glycolipid A-6-2 by normal and mutant human skin fibroblasts. J. Lipid Res. 39 (1998) 1768–1780. [PMID: 9741689]
2.  Zhu, A., Monahan, C., Wang, Z.K. and Goldstein, J. Expression, purification, and characterization of recombinant α-N-acetylgalactosaminidase produced in the yeast Pichia pastoris. Protein Expr. Purif. 8 (1996) 456–462. [PMID: 8954893]
3.  Clark, N.E. and Garman, S.C. The 1.9 Å structure of human α-N-acetylgalactosaminidase: The molecular basis of Schindler and Kanzaki diseases. J. Mol. Biol. 393 (2009) 435–447. [PMID: 19683538]
4.  Hoskins, L.C., Boulding, E.T. and Larson, G. Purification and characterization of blood group A-degrading isoforms of α-N-acetylgalactosaminidase from Ruminococcus torques strain IX-70. J. Biol. Chem. 272 (1997) 7932–7939. [PMID: 9065462]
5.  Harun-Or-Rashid, M., Matsuzawa, T., Satoh, Y., Shiraishi, T., Ando, M., Sadik, G. and Uda, Y. Purification and characterization of α-N-acetylgalactosaminidases I and II from the starfish Asterina amurensis. Biosci. Biotechnol. Biochem. 74 (2010) 256–261. [PMID: 20139603]
6.  Weignerova, L., Filipi, T., Manglova, D. and Kren, V. Induction, purification and characterization of α-N-acetylgalactosaminidase from Aspergillus niger. Appl. Microbiol. Biotechnol. 79 (2008) 769–774. [PMID: 18443780]
7.  Ashida, H., Tamaki, H., Fujimoto, T., Yamamoto, K. and Kumagai, H. Molecular cloning of cDNA encoding α-N-acetylgalactosaminidase from Acremonium sp. and its expression in yeast. Arch. Biochem. Biophys. 384 (2000) 305–310. [PMID: 11368317]
[EC 3.2.1.49 created 1972, modified 2011]
 
 
EC 3.2.1.99     Relevance: 18.9%
Accepted name: arabinan endo-1,5-α-L-arabinanase
Reaction: Endohydrolysis of (1→5)-α-arabinofuranosidic linkages in (1→5)-arabinans
Other name(s): endo-1,5-α-L-arabinanase; endo-α-1,5-arabanase; endo-arabanase; 1,5-α-L-arabinan 1,5-α-L-arabinanohydrolase; arabinan endo-1,5-α-L-arabinosidase (misleading)
Systematic name: 5-α-L-arabinan 5-α-L-arabinanohydrolase
Comments: Acts best on linear 1,5-α-L-arabinan. Also acts on branched arabinan, but more slowly.
References:
1.  Kaji, A. and Saheki, T. Endo-arabinanase from Bacillus subtilis F-11. Biochim. Biophys. Acta 410 (1975) 354–360. [PMID: 1096]
2.  Weinstein, L. and Albersheim, P. Structure of plant cell walls. IX. Purification and partial characterization of a wall-degrading endo-arabinase and an arabinosidase from Bacillus subtilis. Plant Physiol. 63 (1979) 425–432. [PMID: 16660741]
3.  Flipphi, M.J., Panneman, H., van der Veen, P., Visser, J. and de Graaff, L.H. Molecular cloning, expression and structure of the endo-1,5-α-L-arabinase gene of Aspergillus niger. Appl. Microbiol. Biotechnol. 40 (1993) 318–326. [PMID: 7764386]
4.  Leal, T.F. and de Sa-Nogueira, I. Purification, characterization and functional analysis of an endo-arabinanase (AbnA) from Bacillus subtilis. FEMS Microbiol. Lett. 241 (2004) 41–48. [PMID: 15556708]
[EC 3.2.1.99 created 1981, modified 2011]
 
 
EC 3.2.1.82     Relevance: 18.9%
Accepted name: exo-poly-α-digalacturonosidase
Reaction: [(1→4)-α-D-galacturonosyl]n + H2O = α-D-galacturonosyl-(1→4)-D-galacturonate + [(1→4)-α-D-galacturonosyl]n-2
Other name(s): pehX (gene name); poly(1,4-α-D-galactosiduronate) digalacturonohydrolase; exopolygalacturonosidase (misleading); poly[(1→4)-α-D-galactosiduronate] digalacturonohydrolase; exo-poly-α-galacturonosidase
Systematic name: poly[(1→4)-α-D-galactosiduronate] non-reducing-end-digalacturonohydrolase
Comments: The enzyme, characterized from bacteria, hydrolyses the second α-1,4-glycosidic bond from the non-reducing end of polygalacturonate, releasing digalacturonate.
References:
1.  Hasegawa, H. and Nagel, C.W. Isolation of an oligogalacturonate hydrolase from a Bacillus species. Arch. Biochem. Biophys. 124 (1968) 513–520. [PMID: 5661621]
2.  Hatanaka, C. and Ozawa, J. Enzymic degradation of pectic acid. XIII. New exopolygalacturonase producing digalacturonic acid from pectic acid. J. Agric. Chem. Soc. Jpn.. 43 (1968) 764–772.
3.  Hatanaka, C. and Ozawa, J. Ber. des O'Hara Inst. 15 (1971) 47.
4.  He, S.Y. and Collmer, A. Molecular cloning, nucleotide sequence, and marker exchange mutagenesis of the exo-poly-α-D-galacturonosidase-encoding pehX gene of Erwinia chrysanthemi EC16. J. Bacteriol. 172 (1990) 4988–4995. [PMID: 2168372]
[EC 3.2.1.82 created 1972, modified 2019]
 
 
EC 3.2.1.116     Relevance: 18.9%
Accepted name: glucan 1,4-α-maltotriohydrolase
Reaction: Hydrolysis of (1→4)-α-D-glucosidic linkages in amylaceous polysaccharides, to remove successive maltotriose residues from the non-reducing chain ends
Other name(s): exo-maltotriohydrolase; maltotriohydrolase; 1,4-α-D-glucan maltotriohydrolase
Systematic name: 4-α-D-glucan maltotriohydrolase
Comments: cf. EC 3.2.1.2 (β-amylase), EC 3.2.1.60 (glucan 1,4-α-maltotetraohydrolase) and EC 3.2.1.98 (glucan 1,4-α-maltohexaosidase). The products have the α-configuration.
References:
1.  Nakakuki, T., Azuma, K. and Kainuma, K. Action patterns of various exo-amylases and the anomeric configurations of their products. Carbohydr. Res. 128 (1984) 297–310.
[EC 3.2.1.116 created 1989]
 
 
EC 2.4.1.2     Relevance: 18.7%
Accepted name: dextrin dextranase
Reaction: [(1→4)-α-D-glucosyl]n + [(1→6)-α-D-glucosyl]m = [(1→4)-α-D-glucosyl]n-1 + [(1→6)-α-D-glucosyl]m+1
Other name(s): dextrin 6-glucosyltransferase; dextran dextrinase; 1,4-α-D-glucan:1,6-α-D-glucan 6-α-D-glucosyltransferase
Systematic name: (1→4)-α-D-glucan:(1→6)-α-D-glucan 6-α-D-glucosyltransferase
References:
1.  Hehre, E.J. Enzymic synthesis of polysaccharides: a biological type of polymerization. Adv. Enzymol. Relat. Subj. Biochem. 11 (1951) 297–337. [PMID: 24540594]
2.  Hehre, E.J. and Hamilton, D.M. Bacterial conversion of dextrin into a polysaccharide with the serological properties of dextran. Proc. Soc. Exp. Biol. Med. 71 (1949) 336–339. [PMID: 18136472]
3.  Hehre, E.J. and Hamilton, D.M. The biological synthesis of dextran from dextrins. J. Biol. Chem. 192 (1953) 161–174. [PMID: 14917661]
[EC 2.4.1.2 created 1961]
 
 
EC 2.4.1.347     Relevance: 18.7%
Accepted name: α,α-trehalose-phosphate synthase (ADP-forming)
Reaction: ADP-α-D-glucose + D-glucose 6-phosphate = ADP + α,α-trehalose 6-phosphate
Other name(s): otsA (gene name); ADP-glucose—glucose-phosphate glucosyltransferase
Systematic name: ADP-α-D-glucose:D-glucose-6-phosphate 1-α-D-glucosyltransferase (configuration-retaining)
Comments: The enzyme has been reported from the yeast Saccharomyces cerevisiae and from mycobacteria. The enzyme from Mycobacterium tuberculosis can also use UDP-α-D-glucose, but the activity with ADP-α-D-glucose, which is considered the main substrate in vivo, is higher.
References:
1.  Ferreira, J.C., Thevelein, J.M., Hohmann, S., Paschoalin, V.M., Trugo, L.C. and Panek, A.D. Trehalose accumulation in mutants of Saccharomyces cerevisiae deleted in the UDPG-dependent trehalose synthase-phosphatase complex. Biochim. Biophys. Acta 1335 (1997) 40–50. [PMID: 9133641]
2.  Pan, Y.T., Carroll, J.D. and Elbein, A.D. Trehalose-phosphate synthase of Mycobacterium tuberculosis. Cloning, expression and properties of the recombinant enzyme. Eur. J. Biochem. 269 (2002) 6091–6100. [PMID: 12473104]
3.  Asencion Diez, M.D., Demonte, A.M., Syson, K., Arias, D.G., Gorelik, A., Guerrero, S.A., Bornemann, S. and Iglesias, A.A. Allosteric regulation of the partitioning of glucose-1-phosphate between glycogen and trehalose biosynthesis in Mycobacterium tuberculosis. Biochim. Biophys. Acta 1850 (2015) 13–21. [PMID: 25277548]
[EC 2.4.1.347 created 2017]
 
 
EC 3.2.1.137     Relevance: 18.7%
Accepted name: mannan exo-1,2-1,6-α-mannosidase
Reaction: Hydrolysis of (1→2)-α-D- and (1→6)-α-D- linkages in yeast mannan, releasing D-mannose
Other name(s): exo-1,2-1,6-α-mannosidase; 1,2-1,6-α-D-mannan D-mannohydrolase
Systematic name: (1→2)-(1→6)-α-D-mannan D-mannohydrolase
Comments: Mannose residues linked α-D-1,3- are also released, but very slowly.
References:
1.  Takegawa, K., Miki, S., Jikibara, T. and Iwahara, S. Purification and characterization of exo-α-D-mannosidase from a Cellulomonas sp. Biochim. Biophys. Acta 991 (1989) 431–437.
[EC 3.2.1.137 created 1992]
 
 
EC 2.4.1.183     Relevance: 18.7%
Accepted name: α-1,3-glucan synthase
Reaction: UDP-glucose + [α-D-glucosyl-(1→3)]n = UDP + [α-D-glucosyl-(1→3)]n+1
Other name(s): uridine diphosphoglucose-1,3-α-glucan glucosyltransferase; 1,3-α-D-glucan synthase; UDP-glucose:α-D-(1-3)-glucan 3-α-D-glucosyltransferase
Systematic name: UDP-glucose:α-D-(1→3)-glucan 3-α-D-glucosyltransferase
Comments: A glucan primer is needed to begin the reaction, which brings about elongation of the glucan chains.
References:
1.  Andoh, M., Yamashita, Y., Shigeoka, T., Hanada, N. and Takehara, T. [Extension of the length of glucan chain by 1,3-α-D-glucansynthase from Streptococcus mutans serotype.] Koku Eisei Gakkai Zasshi 37 (1987) 516–517.
[EC 2.4.1.183 created 1990]
 
 
EC 2.4.1.43     Relevance: 18.7%
Accepted name: polygalacturonate 4-α-galacturonosyltransferase
Reaction: UDP-α-D-galacturonate + [(1→4)-α-D-galacturonosyl]n = UDP + [(1→4)-α-D-galacturonosyl]n+1
Other name(s): UDP galacturonate-polygalacturonate α-galacturonosyltransferase; uridine diphosphogalacturonate-polygalacturonate α-galacturonosyltransferase; UDP-D-galacturonate:1,4-α-poly-D-galacturonate 4-α-D-galacturonosyltransferase; UDP-D-galacturonate:(1→4)-α-poly-D-galacturonate 4-α-D-galacturonosyltransferase
Systematic name: UDP-α-D-galacturonate:(1→4)-α-poly-D-galacturonate 4-α-D-galacturonosyltransferase (configuration-retaining)
References:
1.  Villemez, C.L., Swanson, A.L. and Hassid, W.Z. Properties of a polygalacturonic acid-synthesizing enzyme system from Phaseolus aureus seedlings. Arch. Biochem. Biophys. 116 (1966) 446–452. [PMID: 5961848]
[EC 2.4.1.43 created 1972]
 
 
EC 2.4.1.140     Relevance: 18.6%
Accepted name: alternansucrase
Reaction: Transfers alternately an α-D-glucosyl residue from sucrose to the 6-position and the 3-position of the non-reducing terminal residue of an α-D-glucan, thus producing a glucan having alternating α-(1→6)- and α-(1→3)-linkages
Other name(s): sucrose-1,6(3)-α-glucan 6(3)-α-glucosyltransferase; sucrose:1,6-, 1,3-α-D-glucan 3-α- and 6-α-D-glucosyltransferase; sucrose:1,6(1,3)-α-D-glucan 6(3)-α-D-glucosyltransferase
Systematic name: sucrose:(1→6)[(1→3)]-α-D-glucan 6(3)-α-D-glucosyltransferase
Comments: The glucansucrases transfer a D-glucosyl residue from sucrose to a glucan chain. They are classified based on the linkage by which they attach the transferred residue. In some cases, in which the enzyme forms more than one linkage type, classification relies on the relative proportion of the linkages that are generated. This enzyme forms both α(1→3) and α(1→6) linkages in approximately equal amounts by alternating the linkage type. cf. EC 2.4.1.125, sucrose—1,6-α-glucan 3(6)-α-glucosyltransferase.
References:
1.  Cote, G.L. and Robyt, J.F. Isolation and partial characterization of an extracellular glucansucrase from Leuconostoc mesenteroides NRRL B-1355 that synthesizes an alternating (1→6), (1→3)-α-D-glucan. Carbohydr. Res. 101 (1982) 57–74. [PMID: 7060056]
2.  Arguello-Morales, M.A., Remaud-Simeon, M., Pizzut, S., Sarcabal, P., Willemot, R. and Monsan, P. Sequence analysis of the gene encoding alternansucrase, a sucrose glucosyltransferase from Leuconostoc mesenteroides NRRL B-1355. FEMS Microbiol. Lett. 182 (2000) 81–85. [PMID: 10612736]
[EC 2.4.1.140 created 1984, modified 2003]
 
 
EC 3.2.1.210     Relevance: 18.6%
Accepted name: endoplasmic reticulum Man8GlcNAc2 1,2-α-mannosidase
Reaction: Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) + H2O = Man7GlcNAc2-[protein] (isomer 7A1,2,3B3) + D-mannopyranose
Glossary: Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) = {α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein]
Man7GlcNAc2-[protein] (isomer 7A1,2,3B3) = {α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein]
Other name(s): MNL1 (gene name)
Systematic name: Man8GlcNAc2-[protein] 2-α-mannohydrolase (configuration-inverting)
Comments: In yeast this activity is catalysed by a dedicated enzyme that processes unfolded protein-bound Man8GlcNAc2 N-glycans within the endoplasmic reticulum to Man7GlcNAc2. The exposed α-1,6-linked mannose residue in the product enables the recognition by the YOS9 lectin, targeting the proteins for degradation. In mammalian cells this activity is part of the regular processing of N-glycosylated proteins, and is not associated with protein degradation. It is carried out by EC 3.2.1.113, Golgi mannosyl-oligosaccharide 1,2-α-mannosidase. The names of the isomers listed here are based on a nomenclature system proposed by Prien et al [5].
References:
1.  Nakatsukasa, K., Nishikawa, S., Hosokawa, N., Nagata, K. and Endo, T. Mnl1p, an α -mannosidase-like protein in yeast Saccharomyces cerevisiae, is required for endoplasmic reticulum-associated degradation of glycoproteins. J. Biol. Chem. 276 (2001) 8635–8638. [PMID: 11254655]
2.  Jakob, C.A., Bodmer, D., Spirig, U., Battig, P., Marcil, A., Dignard, D., Bergeron, J.J., Thomas, D.Y. and Aebi, M. Htm1p, a mannosidase-like protein, is involved in glycoprotein degradation in yeast. EMBO Rep. 2 (2001) 423–430. [PMID: 11375935]
3.  Quan, E.M., Kamiya, Y., Kamiya, D., Denic, V., Weibezahn, J., Kato, K. and Weissman, J.S. Defining the glycan destruction signal for endoplasmic reticulum-associated degradation. Mol. Cell 32 (2008) 870–877. [PMID: 19111666]
4.  Clerc, S., Hirsch, C., Oggier, D.M., Deprez, P., Jakob, C., Sommer, T. and Aebi, M. Htm1 protein generates the N-glycan signal for glycoprotein degradation in the endoplasmic reticulum. J. Cell Biol. 184 (2009) 159–172. [PMID: 19124653]
5.  Prien, J.M., Ashline, D.J., Lapadula, A.J., Zhang, H. and Reinhold, V.N. The high mannose glycans from bovine ribonuclease B isomer characterization by ion trap MS. J. Am. Soc. Mass Spectrom. 20 (2009) 539–556. [PMID: 19181540]
6.  Chantret, I., Kodali, V.P., Lahmouich, C., Harvey, D.J. and Moore, S.E. Endoplasmic reticulum-associated degradation (ERAD) and free oligosaccharide generation in Saccharomyces cerevisiae. J. Biol. Chem. 286 (2011) 41786–41800. [PMID: 21979948]
[EC 3.2.1.210 created 2019]
 
 
EC 2.7.1.235     Relevance: 18.6%
Accepted name: lipopolysaccharide core heptose(I) kinase
Reaction: ATP + an α-Hep-(1→3)-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] = ADP + an α-Hep-(1→3)-4-O-phospho-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A]
Glossary: Lipid A is a lipid component of the lipopolysaccharides (LPS) of Gram-negative bacteria. It usually consists of two glucosamine units connected by a β(1→6) bond and decorated with four to seven acyl chains and up to two phosphate groups.
Hep = L-glycero-β-D-manno-heptose
Other name(s): WaaP; RfaP
Systematic name: ATP:an α-Hep-(1→3)-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] heptoseI 4-O-phosphotransferase
Comments: The enzyme catalyses the phosphorylation of L-glycero-D-manno-heptose I (the first heptose added to the lipid, Hep I) in the biosynthesis of the inner core oligosaccharide of the lipopolysaccharide (endotoxin) of some Gram-negative bacteria.
References:
1.  Yethon, J.A. and Whitfield, C. Purification and characterization of WaaP from Escherichia coli, a lipopolysaccharide kinase essential for outer membrane stability. J. Biol. Chem. 276 (2001) 5498–5504. [PMID: 11069912]
2.  Zhao, X. and Lam, J.S. WaaP of Pseudomonas aeruginosa is a novel eukaryotic type protein-tyrosine kinase as well as a sugar kinase essential for the biosynthesis of core lipopolysaccharide. J. Biol. Chem. 277 (2002) 4722–4730. [PMID: 11741974]
3.  Kreamer, N.NK., Chopra, R., Caughlan, R.E., Fabbro, D., Fang, E., Gee, P., Hunt, I., Li, M., Leon, B.C., Muller, L., Vash, B., Woods, A.L., Stams, T., Dean, C.R. and Uehara, T. Acylated-acyl carrier protein stabilizes the Pseudomonas aeruginosa WaaP lipopolysaccharide heptose kinase. Sci. Rep. 8:14124 (2018). [PMID: 30237436]
[EC 2.7.1.235 created 2021]
 
 
EC 3.2.1.163     Relevance: 18.6%
Accepted name: 1,6-α-D-mannosidase
Reaction: Hydrolysis of the (1→6)-linked α-D-mannose residues in α-D-Manp-(1→6)-D-Manp
Systematic name: (1→6)-α-mannosyl α-D-mannohydrolase
Comments: The enzyme is specific for (1→6)-linked mannobiose and has no activity towards any other linkages, or towards p-nitrophenyl-α-D-mannopyranoside or baker’s yeast mannan. It is strongly inhibited by Mn2+ but does not require Ca2+ or any other metal cofactor for activity.
References:
1.  Athanasopoulos, V.I., Niranjan, K. and Rastall, R.A. The production, purification and characterisation of two novel α-D-mannosidases from Aspergillus phoenicis. Carbohydr. Res. 340 (2005) 609–617. [PMID: 15721331]
[EC 3.2.1.163 created 2007]
 
 
EC 2.3.1.288     Relevance: 18.6%
Accepted name: 2-O-sulfo trehalose long-chain-acyltransferase
Reaction: (1) stearoyl-CoA + 2-O-sulfo-α,α-trehalose = 2-O-sulfo-2′-stearoyl-α,α-trehalose + CoA
(2) palmitoyl-CoA + 2-O-sulfo-α,α-trehalose = 2-O-sulfo-2′-palmitoyl-α,α-trehalose + CoA
Other name(s): papA2 (gene name)
Systematic name: acyl-CoA:2-O-sulfo-α,α-trehalose 2′-long-chain-acyltransferase
Comments: This mycobacterial enzyme catalyses the acylation of 2-O-sulfo-α,α-trehalose at the 2′ position by a C16 or C18 fatty acyl group during the biosynthesis of mycobacterial sulfolipids.
References:
1.  Kumar, P., Schelle, M.W., Jain, M., Lin, F.L., Petzold, C.J., Leavell, M.D., Leary, J.A., Cox, J.S. and Bertozzi, C.R. PapA1 and PapA2 are acyltransferases essential for the biosynthesis of the Mycobacterium tuberculosis virulence factor sulfolipid-1. Proc. Natl. Acad. Sci. USA 104 (2007) 11221–11226. [PMID: 17592143]
2.  Seeliger, J.C., Holsclaw, C.M., Schelle, M.W., Botyanszki, Z., Gilmore, S.A., Tully, S.E., Niederweis, M., Cravatt, B.F., Leary, J.A. and Bertozzi, C.R. Elucidation and chemical modulation of sulfolipid-1 biosynthesis in Mycobacterium tuberculosis. J. Biol. Chem. 287 (2012) 7990–8000. [PMID: 22194604]
[EC 2.3.1.288 created 2019]
 
 
EC 3.2.1.84     Relevance: 18.6%
Accepted name: glucan 1,3-α-glucosidase
Reaction: Hydrolysis of terminal (1→3)-α-D-glucosidic links in (1→3)-α-D-glucans
Other name(s): exo-1,3-α-glucanase; glucosidase II; 1,3-α-D-glucan 3-glucohydrolase
Systematic name: 3-α-D-glucan 3-glucohydrolase
Comments: Does not act on nigeran.
References:
1.  Zonneveld, B.J.M. A new type of enzyme, and exo-splitting α-1,3 glucanase from non-induced cultures of Aspergillus nidulans. Biochim. Biophys. Acta 258 (1972) 541–547. [PMID: 4622000]
[EC 3.2.1.84 created 1972]
 
 
EC 2.4.1.245     Relevance: 18.4%
Accepted name: α,α-trehalose synthase
Reaction: NDP-α-D-glucose + D-glucose = α,α-trehalose + NDP
Glossary: NDP = a nucleoside diphosphate
Other name(s): trehalose synthase; trehalose synthetase; UDP-glucose:glucose 1-glucosyltransferase; TreT; PhGT; ADP-glucose:D-glucose 1-α-D-glucosyltransferase
Systematic name: NDP-α-D-glucose:D-glucose 1-α-D-glucosyltransferase
Comments: Requires Mg2+ for maximal activity [1]. The enzyme-catalysed reaction is reversible [1]. In the reverse direction to that shown above, the enzyme is specific for α,α-trehalose as substrate, as it cannot use α- or β-paranitrophenyl glucosides, maltose, sucrose, lactose or cellobiose [1]. While the enzymes from the thermophilic bacterium Rubrobacter xylanophilus and the hyperthermophilic archaeon Pyrococcus horikoshii can use ADP-, UDP- and GDP-α-D-glucose to the same extent [2,3], that from the hyperthermophilic archaeon Thermococcus litoralis has a marked preference for ADP-α-D-glucose [1] and that from the hyperthermophilic archaeon Thermoproteus tenax has a marked preference for UDP-α-D-glucose [4].
References:
1.  Qu, Q., Lee, S.J. and Boos, W. TreT, a novel trehalose glycosyltransferring synthase of the hyperthermophilic archaeon Thermococcus litoralis. J. Biol. Chem. 279 (2004) 47890–47897. [PMID: 15364950]
2.  Ryu, S.I., Park, C.S., Cha, J., Woo, E.J. and Lee, S.B. A novel trehalose-synthesizing glycosyltransferase from Pyrococcus horikoshii: molecular cloning and characterization. Biochem. Biophys. Res. Commun. 329 (2005) 429–436. [PMID: 15737605]
3.  Nobre, A., Alarico, S., Fernandes, C., Empadinhas, N. and da Costa, M.S. A unique combination of genetic systems for the synthesis of trehalose in Rubrobacter xylanophilus: properties of a rare actinobacterial TreT. J. Bacteriol. 190 (2008) 7939–7946. [PMID: 18835983]
4.  Kouril, T., Zaparty, M., Marrero, J., Brinkmann, H. and Siebers, B. A novel trehalose synthesizing pathway in the hyperthermophilic Crenarchaeon Thermoproteus tenax: the unidirectional TreT pathway. Arch. Microbiol. 190 (2008) 355–369. [PMID: 18483808]
[EC 2.4.1.245 created 2008, modified 2013]
 
 
EC 3.2.1.61     Relevance: 18.4%
Accepted name: mycodextranase
Reaction: Endohydrolysis of (1→4)-α-D-glucosidic linkages in α-D-glucans containing both (1→3)- and (1→4)-bonds
Other name(s): 1,3-1,4-α-D-glucan 4-glucanohydrolase
Systematic name: (1→3)-(1→4)-α-D-glucan 4-glucanohydrolase
Comments: Products are nigerose and 4-α-D-nigerosylglucose. No hydrolysis of α-D-glucans containing only 1,3- or 1,4-bonds.
References:
1.  Tung, K. and Nordin, J.H. Structure of the tetrasaccharide produced by the hydrolysis of nigeran by the enzyme mycodextranase. Biochim. Biophys. Acta 158 (1968) 154–156. [PMID: 5652425]
[EC 3.2.1.61 created 1972]
 
 
EC 2.4.1.82     Relevance: 18.4%
Accepted name: galactinol—sucrose galactosyltransferase
Reaction: α-D-galactosyl-(1→3)-1D-myo-inositol + sucrose = myo-inositol + raffinose
Glossary: raffinose = β-D-fructofuranosyl α-D-galactopyranosyl-(1→6)-α-D-glucopyranoside
Other name(s): 1-α-D-galactosyl-myo-inositol:sucrose 6-α-D-galactosyltransferase; α-D-galactosyl-(1→3)-myo-inositol:sucrose 6-α-D-galactosyltransferase; raffinose synthase; RafS
Systematic name: α-D-galactosyl-(1→3)-1D-myo-inositol:sucrose 6-α-D-galactosyltransferase
Comments: 4-Nitrophenyl α-D-galactopyranoside can also act as donor. The enzyme also catalyses an exchange reaction between raffinose and sucrose (cf. EC 2.4.1.123, inositol 3-α-galactosyltransferase).
References:
1.  Lehle, L. and Tanner, W. The function of myo-inositol in the biosynthesis of raffinose. Purification and characterization of galactinol:sucrose 6-galactosyltransferase from Vicia faba seeds. Eur. J. Biochem. 38 (1973) 103–110. [PMID: 4774118]
2.  Lehle, L., Tanner, W. and Kandler, O. Myo-inositol, a cofactor in the biosynthesis of raffinose. Hoppe-Seyler's Z. Physiol. Chem. 351 (1970) 1494–1498. [PMID: 5491608]
[EC 2.4.1.82 created 1976, modified 2003]
 
 
EC 2.4.1.161     Relevance: 18.4%
Accepted name: oligosaccharide 4-α-D-glucosyltransferase
Reaction: Transfers the non-reducing terminal α-D-glucose residue from a (1→4)-α-D-glucan to the 4-position of a free glucose or of a glucosyl residue at the non-reducing terminus of a (1→4)-α-D-glucan, thus bringing about the rearrangement of oligosaccharides
Other name(s): amylase III; 1,4-α-glucan:1,4-α-glucan 4-α-glucosyltransferase; 1,4-α-D-glucan:1,4-α-D-glucan 4-α-D-glucosyltransferase; α-1,4-transglucosylase
Systematic name: (1→4)-α-D-glucan:(1→4)-α-D-glucan 4-α-D-glucosyltransferase
Comments: The enzyme acts on amylose, amylopectin, glycogen and maltooligosaccharides. No detectable free glucose is formed, indicating the enzyme does not act as a hydrolase. The enzyme from the bacterium Cellvibrio japonicus has the highest activity with maltotriose as a donor, and also accepts maltose [3], while the enzyme from amoeba does not accept maltose [1,2]. Oligosaccharides with 1→6 linkages cannot function as donors, but can act as acceptors [3]. Unlike EC 2.4.1.25, 4-α-glucanotransferase, this enzyme can transfer only a single glucosyl residue.
References:
1.  Nebinger, P. Separation and characterization of four different amylases of Entamoeba histolytica. I. Purification and properties. Biol. Chem. Hoppe-Seyler 367 (1986) 161–167. [PMID: 2423097]
2.  Nebinger, P. Separation and characterization of four different amylases of Entamoeba histolytica. II. Characterization of amylases. Biol. Chem. Hoppe-Seyler 367 (1986) 169–176. [PMID: 2423098]
3.  Larsbrink, J., Izumi, A., Hemsworth, G.R., Davies, G.J. and Brumer, H. Structural enzymology of Cellvibrio japonicus Agd31B protein reveals α-transglucosylase activity in glycoside hydrolase family 31. J. Biol. Chem. 287 (2012) 43288–43299. [PMID: 23132856]
[EC 2.4.1.161 created 1989, modified 2013]
 
 
EC 2.4.1.131     Relevance: 18.4%
Accepted name: GDP-Man:Man3GlcNAc2-PP-dolichol α-1,2-mannosyltransferase
Reaction: 2 GDP-α-D-mannose + α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = 2 GDP + α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol
Other name(s): ALG11; ALG11 mannosyltransferase; LEW3 (gene name); At2G40190 (gene name); gmd3 (gene name); galactomannan deficiency protein 3; GDP-mannose:glycolipid 1,2-α-D-mannosyltransferase; glycolipid 2-α-mannosyltransferase; GDP-mannose:glycolipid 2-α-D-mannosyltransferase; GDP-Man:Man3GlcNAc2-PP-Dol α-1,2-mannosyltransferase; GDP-α-D-mannose:D-Man-α-(1→3)-[D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol 2-α-D-mannosyltransferase
Systematic name: GDP-α-D-mannose:α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 2-α-D-mannosyltransferase (configuration-retaining)
Comments: The biosynthesis of asparagine-linked glycoproteins (N-linked protein glycosylation) utilizes a dolichyl diphosphate-linked glycosyl donor, which is assembled by the series of membrane-bound glycosyltransferases that comprise the dolichol pathway. ALG11 mannosyltransferase from Saccharomyces cerevisiae carries out two sequential steps in the formation of the lipid-linked core oligosaccharide, adding two mannose residues in α(1→2) linkages to the nascent oligosaccharide.
References:
1.  O'Reilly, M.K., Zhang, G. and Imperiali, B. In vitro evidence for the dual function of Alg2 and Alg11: essential mannosyltransferases in N-linked glycoprotein biosynthesis. Biochemistry 45 (2006) 9593–9603. [PMID: 16878994]
2.  Absmanner, B., Schmeiser, V., Kampf, M. and Lehle, L. Biochemical characterization, membrane association and identification of amino acids essential for the function of Alg11 from Saccharomyces cerevisiae, an α1,2-mannosyltransferase catalysing two sequential glycosylation steps in the formation of the lipid-linked core oligosaccharide. Biochem. J. 426 (2010) 205–217. [PMID: 19929855]
3.  Schutzbach, J.S., Springfield, J.D. and Jensen, J.W. The biosynthesis of oligosaccharide-lipids. Formation of an α-1,2-mannosyl-mannose linkage. J. Biol. Chem. 255 (1980) 4170–4175. [PMID: 6154707]
[EC 2.4.1.131 created 1984, modified 2011, modified 2012]
 
 
EC 3.2.1.20     Relevance: 18.3%
Accepted name: α-glucosidase
Reaction: Hydrolysis of terminal, non-reducing (1→4)-linked α-D-glucose residues with release of D-glucose
Other name(s): maltase; glucoinvertase; glucosidosucrase; maltase-glucoamylase; α-glucopyranosidase; glucosidoinvertase; α-D-glucosidase; α-glucoside hydrolase; α-1,4-glucosidase
Systematic name: α-D-glucoside glucohydrolase
Comments: This single entry covers a group of enzymes whose specificity is directed mainly towards the exohydrolysis of (1→4)-α-glucosidic linkages, and that hydrolyse oligosaccharides rapidly, relative to polysaccharide, which are hydrolysed relatively slowly, or not at all. The intestinal enzyme also hydrolyses polysaccharides, catalysing the reactions of EC 3.2.1.3 glucan 1,4-α-glucosidase and, more slowly, hydrolyses (1→6)-α-D-glucose links.
References:
1.  Bruni, C.B., Sica, V., Auricchio, F. and Covelli, I. Further kinetic and structural characterization of the lysosomal α-D-glucoside glucohydrolase from cattle liver. Biochim. Biophys. Acta 212 (1970) 470–477. [PMID: 5466143]
2.  Flanagan, P.R. and Forstner, G.G. Purification of rat intestinal maltase/glucoamylase and its anomalous dissociation either by heat or by low pH. Biochem. J. 173 (1978) 553–563. [PMID: 29602]
3.  Larner, J. Other glucosidases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 4, Academic Press, New York, 1960, pp. 369–378.
4.  Sivikami, S. and Radhakrishnan, A.N. Purification of rabbit intestinal glucoamylase by affinity chromatography on Sephadex G-200. Indian J. Biochem. Biophys. 10 (1973) 283–284. [PMID: 4792946]
5.  Sørensen, S.H., Norén, O., Sjöström, H. and Danielsen, E.M. Amphiphilic pig intestinal microvillus maltase/glucoamylase. Structure and specificity. Eur. J. Biochem. 126 (1982) 559–568. [PMID: 6814909]
[EC 3.2.1.20 created 1961]
 
 
EC 2.4.1.292     Relevance: 18.3%
Accepted name: GalNAc-α-(1→4)-GalNAc-α-(1→3)-diNAcBac-PP-undecaprenol α-1,4-N-acetyl-D-galactosaminyltransferase
Reaction: 3 UDP-N-acetyl-α-D-galactosamine + GalNAc-α-(1→4)-GalNAc-α-(1→3)-diNAcBac-PP-tritrans,heptacis-undecaprenol = 3 UDP + [GalNAc-α-(1→4)]4-GalNAc-α-(1→3)-diNAcBac-PP-tritrans,heptacis-undecaprenol
Glossary: diNAcBac = N,N′-diacetyl-D-bacillosamine = 2,4-diacetamido-2,4,6-trideoxy-D-glucopyranose
Other name(s): PglH
Systematic name: UDP-N-acetyl-α-D-galactosamine:GalNAc-α-(1→4)-GalNAc-α-(1→3)-diNAcBac-PP-tritrans,heptacis-undecaprenol 4-α-N-acetyl-D-galactosaminyltransferase
Comments: Isolated from Campylobacter jejuni. Part of a bacterial N-linked glycosylation pathway.
References:
1.  Glover, K.J., Weerapana, E. and Imperiali, B. In vitro assembly of the undecaprenylpyrophosphate-linked heptasaccharide for prokaryotic N-linked glycosylation. Proc. Natl. Acad. Sci. USA 102 (2005) 14255–14259. [PMID: 16186480]
2.  Troutman, J.M. and Imperiali, B. Campylobacter jejuni PglH is a single active site processive polymerase that utilizes product inhibition to limit sequential glycosyl transfer reactions. Biochemistry 48 (2009) 2807–2816. [PMID: 19159314]
3.  Borud, B., Viburiene, R., Hartley, M.D., Paulsen, B.S., Egge-Jacobsen, W., Imperiali, B. and Koomey, M. Genetic and molecular analyses reveal an evolutionary trajectory for glycan synthesis in a bacterial protein glycosylation system. Proc. Natl. Acad. Sci. USA 108 (2011) 9643–9648. [PMID: 21606362]
[EC 2.4.1.292 created 2012]
 
 
EC 2.4.1.25     Relevance: 18.2%
Accepted name: 4-α-glucanotransferase
Reaction: Transfers a segment of a (1→4)-α-D-glucan to a new position in an acceptor, which may be glucose or a (1→4)-α-D-glucan
Other name(s): disproportionating enzyme; dextrin glycosyltransferase; D-enzyme; debranching enzyme maltodextrin glycosyltransferase; amylomaltase; dextrin transglycosylase; 1,4-α-D-glucan:1,4-α-D-glucan 4-α-D-glycosyltransferase
Systematic name: (1→4)-α-D-glucan:(1→4)-α-D-glucan 4-α-D-glycosyltransferase
Comments: This entry covers the former separate entry for EC 2.4.1.3 (amylomaltase). The plant enzyme has been termed D-enzyme. An enzymic activity of this nature forms part of the mammalian and yeast glycogen debranching system (see EC 3.2.1.33 amylo-α-1,6-glucosidase).
References:
1.  Hehre, E.J. Enzymic synthesis of polysaccharides: a biological type of polymerization. Adv. Enzymol. Relat. Subj. Biochem. 11 (1951) 297–337. [PMID: 24540594]
2.  Lukomskaya, I.S. Synthesis of oligosaccharides with α-1,6-bonds by enzyme preparations from liver and muscle. Dokl. Akad. Nauk S.S.S.R. 129 (1959) 1172–1175. (in Russian)
3.  Pazur, J.H. and Okada, S. The isolation and mode of action of a bacterial glucanosyltransferase. J. Biol. Chem. 243 (1968) 4732–4738. [PMID: 4972097]
4.  Walker, G.J. and Whelan, W.J. Synthesis of amylose by potato D-enzyme. Nature 183 (1959) 46. [PMID: 13622683]
5.  Whelan, W.H. Enzymic explorations of the structures of starch and glycogen. Biochem. J. 122 (1971) 609–622. [PMID: 5001952]
[EC 2.4.1.25 created 1965 (EC 2.4.1.3 created 1961, incorporated 1972)]
 
 
EC 2.4.3.7     Relevance: 18.2%
Accepted name: α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase
Reaction: CMP-N-acetylneuraminate + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-[N-acetyl-α-neuraminyl-(2→6)]-N-acetyl-D-galactosaminyl-R
Other name(s): sialyltransferase; cytidine monophosphoacetylneuraminate-(α-N-acetylneuraminyl-2,3-β-galactosyl-1,3)-N-acetylgalactosaminide-α-2,6-sialyltransferase; α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetyl-galactosaminide α-2,6-sialyltransferase; SIAT7; ST6GALNAC; (α-N-acetylneuraminyl-2,3-β-galactosyl-1,3)-N-acetyl-galactosaminide 6-α-sialyltransferase; CMP-N-acetylneuraminate:(α-N-acetylneuraminyl-2,3-β-D-galactosyl-1,3)-N-acetyl-D-galactosaminide α-2,6-N-acetylneuraminyl-transferase
Systematic name: CMP-N-acetylneuraminate:N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)- N-acetyl-D-galactosaminide galactosamine-6-α-N-acetylneuraminyltransferase
Comments: Attaches N-acetylneuraminic acid in α-2,6-linkage to N-acetylgalactosamine only when present in the structure of α-N-acetylneuraminyl-(2→3)-β-galactosyl-(1→3)-N-acetylgalactosaminyl-R, where R may be protein or p-nitrophenol. Not identical with EC 2.4.3.3 α-N-acetylgalactosaminide α-2,6-sialyltransferase.
References:
1.  Bergh, M.L.E., Hooghwinkel, G.J.M. and Van den Eijnden, D.H. Biosynthesis of the O-glycosidically linked oligosaccharide chains of fetuin. Indications for an α-N-acetylgalactosaminide α2→6 sialyltransferase with a narrow acceptor specificity in fetal calf liver. J. Biol. Chem. 258 (1983) 7430–7436. [PMID: 6190802]
[EC 2.4.3.7 created 1984 as EC 2.4.99.7, modified 1986, modified 2004, transferred 2022 to EC 2.4.3.7]
 
 
EC 3.2.1.1     Relevance: 18.1%
Accepted name: α-amylase
Reaction: Endohydrolysis of (1→4)-α-D-glucosidic linkages in polysaccharides containing three or more (1→4)-α-linked D-glucose units
Other name(s): glycogenase; α amylase; endoamylase; Taka-amylase A; 1,4-α-D-glucan glucanohydrolase
Systematic name: 4-α-D-glucan glucanohydrolase
Comments: Acts on starch, glycogen and related polysaccharides and oligosaccharides in a random manner; reducing groups are liberated in the α-configuration. The term "α" relates to the initial anomeric configuration of the free sugar group released and not to the configuration of the linkage hydrolysed.
References:
1.  Fischer, E.H. and Stein, E.A. α-Amylases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 4, Academic Press, New York, 1960, pp. 313–343.
2.  Manners, D.J. Enzymic synthesis and degradation of starch and glycogen. Adv. Carbohydr. Chem. 17 (1962) 371–430.
3.  Schwimmer, S. and Balls, A.K. Isolation and properties of crystalline α-amylase from germinated barley. J. Biol. Chem. 179 (1949) 1063–1074. [PMID: 18134570]
[EC 3.2.1.1 created 1961]
 
 
EC 2.4.99.16     Relevance: 18.1%
Accepted name: starch synthase (maltosyl-transferring)
Reaction: α-maltose 1-phosphate + [(1→4)-α-D-glucosyl]n = phosphate + [(1→4)-α-D-glucosyl]n+2
Other name(s): α1,4-glucan:maltose-1-P maltosyltransferase; GMPMT
Systematic name: α-maltose 1-phosphate:(1→4)-α-D-glucan 4-α-D-maltosyltransferase
Comments: The enzyme from the bacterium Mycobacterium smegmatis is specific for maltose. It has no activity with α-D-glucose.
References:
1.  Elbein, A.D., Pastuszak, I., Tackett, A.J., Wilson, T. and Pan, Y.T. Last step in the conversion of trehalose to glycogen: a mycobacterial enzyme that transfers maltose from maltose 1-phosphate to glycogen. J. Biol. Chem. 285 (2010) 9803–9812. [PMID: 20118231]
2.  Syson, K., Stevenson, C.E., Rejzek, M., Fairhurst, S.A., Nair, A., Bruton, C.J., Field, R.A., Chater, K.F., Lawson, D.M. and Bornemann, S. Structure of Streptomyces maltosyltransferase GlgE, a homologue of a genetically validated anti-tuberculosis target. J. Biol. Chem. 286 (2011) 38298–38310. [PMID: 21914799]
[EC 2.4.99.16 created 2012]
 
 
EC 3.2.1.18     Relevance: 18.1%
Accepted name: exo-α-sialidase
Reaction: Hydrolysis of α-(2→3)-, α-(2→6)-, α-(2→8)- glycosidic linkages of terminal sialic acid residues in oligosaccharides, glycoproteins, glycolipids, colominic acid and synthetic substrates
Other name(s): neuraminidase; sialidase; α-neuraminidase; acetylneuraminidase
Systematic name: acetylneuraminyl hydrolase
Comments: The enzyme does not act on 4-O-acetylated sialic acids. endo-α-Sialidase activity is listed as EC 3.2.1.129, endo-α-sialidase. See also EC 4.2.2.15 anhydrosialidase.
References:
1.  Schauer, R. Sialic acids. Adv. Carbohydr. Chem. Biochem. 40 (1982) 131–234. [PMID: 6762816]
2.  Cabezas, J.A. Some questions and suggestions on the type references of the official nomenclature (IUB) for sialidase(s) and endosialidase. Biochem. J. 278 (1991) 311–312. [PMID: 1883340]
[EC 3.2.1.18 created 1961, modified 1999]
 
 
EC 2.4.1.166     Relevance: 18.1%
Accepted name: raffinose—raffinose α-galactosyltransferase
Reaction: 2 raffinose = 1F-α-D-galactosylraffinose + sucrose
Glossary: raffinose = β-D-fructofuranosyl α-D-galactopyranosyl-(1→6)-α-D-glucopyranoside
Other name(s): raffinose (raffinose donor) galactosyltransferase; raffinose:raffinose α-galactosyltransferase; raffinose—raffinose α-galactotransferase
Systematic name: raffinose:raffinose α-D-galactosyltransferase
Comments: The 3F position of raffinose can also act as galactosyl acceptor; the enzyme is involved in the accumulation of the tetrasaccharides lychnose and isolychnose in the leaves of Cerastium arvense and other plants of the family Caryophyllaceae during late autumn.
References:
1.  Hopf, H., Gruber, G., Zinn, A. and Kandler, O. Physiology and biosynthesis of lychnose in Cerastium arvense. Planta 162 (1984) 283–288. [PMID: 24253101]
[EC 2.4.1.166 created 1989]
 
 
EC 2.4.1.258     Relevance: 18%
Accepted name: dolichyl-P-Man:Man5GlcNAc2-PP-dolichol α-1,3-mannosyltransferase
Reaction: dolichyl β-D-mannosyl phosphate + α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→3)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol + dolichyl phosphate
Other name(s): Man5GlcNAc2-PP-Dol mannosyltransferase; ALG3; dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl mannosyltransferase; Not56-like protein; Alg3 α-1,3-mannosyl transferase; Dol-P-Man:Man5GlcNAc2-PP-Dol α-1,3-mannosyltransferase; dolichyl β-D-mannosyl phosphate:D-Man-α-(1→2)-D-Man-α-(1→2)-D-Man-α-(1→3)-[D-Man-α-(1→6)]-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol α-1,3-mannosyltransferase
Systematic name: dolichyl β-D-mannosyl-phosphate:α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 3-α-D-mannosyltransferase (configuration-inverting)
Comments: The formation of N-glycosidic linkages of glycoproteins involves the ordered assembly of the common Glc3Man9GlcNAc2 core-oligosaccharide on the lipid carrier dolichyl diphosphate. Early mannosylation steps occur on the cytoplasmic side of the endoplasmic reticulum with GDP-Man as donor, the final reactions from Man5GlcNAc2-PP-dolichol to Man9Glc-NAc2-PP-dolichol on the lumenal side use dolichyl β-D-mannosyl phosphate. The first step of this assembly pathway on the luminal side of the endoplasmic reticulum is catalysed by ALG3.
References:
1.  Sharma, C.B., Knauer, R. and Lehle, L. Biosynthesis of lipid-linked oligosaccharides in yeast: the ALG3 gene encodes the Dol-P-Man:Man5GlcNAc2-PP-Dol mannosyltransferase. Biol. Chem. 382 (2001) 321–328. [PMID: 11308030]
2.  Cipollo, J.F. and Trimble, R.B. The accumulation of Man(6)GlcNAc(2)-PP-dolichol in the Saccharomyces cerevisiae Δalg9 mutant reveals a regulatory role for the Alg3p α1,3-Man middle-arm addition in downstream oligosaccharide-lipid and glycoprotein glycan processing. J. Biol. Chem. 275 (2000) 4267–4277. [PMID: 10660594]
[EC 2.4.1.258 created 1976 as EC 2.4.1.130, part transferred 2011 to EC 2.4.1.258, modified 2012]
 
 
EC 2.4.1.373     Relevance: 18%
Accepted name: α-(1→2) branching sucrase
Reaction: sucrose + a (1→6)-α-D-glucan = D-fructose + a (1→6)-α-D-glucan containing a (1→2)-α-D-glucose branch
Systematic name: sucrose:(1→6)-α-D-glucan 2-α-D-glucosyl-transferase
Comments: The glucansucrases transfer a D-glucosyl residue from sucrose to a glucan chain. They are classified based on the linkage by which they attach the transferred residue. In some cases, in which the enzyme forms more than one linkage type, classification relies on the relative proportion of the linkages that are generated. This enzyme introduces α(1→2) branches into (1→6)-α-D-glucans.
References:
1.  Fabre, E., Bozonnet, S., Arcache, A., Willemot, R.M., Vignon, M., Monsan, P. and Remaud-Simeon, M. Role of the two catalytic domains of DSR-E dextransucrase and their involvement in the formation of highly α-1,2 branched dextran. J. Bacteriol. 187 (2005) 296–303. [PMID: 15601714]
2.  Brison, Y., Laguerre, S., Lefoulon, F., Morel, S., Monties, N., Potocki-Veronese, G., Monsan, P. and Remaud-Simeon, M. Branching pattern of gluco-oligosaccharides and 1.5kDa dextran grafted by the α-1,2 branching sucrase GBD-CD2. Carbohydr. Polym. 94 (2013) 567–576. [PMID: 23544576]
3.  Passerini, D., Vuillemin, M., Ufarte, L., Morel, S., Loux, V., Fontagne-Faucher, C., Monsan, P., Remaud-Simeon, M. and Moulis, C. Inventory of the GH70 enzymes encoded by Leuconostoc citreum NRRL B-1299 - identification of three novel α-transglucosylases. FEBS J. 282 (2015) 2115–2130. [PMID: 25756290]
[EC 2.4.1.373 created 2019]
 
 
EC 2.4.1.199     Relevance: 18%
Accepted name: β-mannosylphosphodecaprenol—mannooligosaccharide 6-mannosyltransferase
Reaction: β-D-mannosylphosphodecaprenol + (1→6)-α-D-mannosyloligosaccharide = decaprenol phosphate + (1→6)-α-D-mannosyl-(1→6)-α-D-mannosyl-oligosaccharide
Other name(s): mannosylphospholipid-methylmannoside α-1,6-mannosyltransferase; β-D-mannosylphosphodecaprenol:1,6-α-D-mannosyloligosaccharide 1,6-α-D-mannosyltransferase
Systematic name: β-D-mannosylphosphodecaprenol:(1→6)-α-D-mannosyloligosaccharide 6-α-D-mannosyltransferase
Comments: Involved in the formation of mannooligosaccharides in the membrane of Mycobacterium smegmatis.
References:
1.  Yokoyama, K. and Ballou, C.E. Synthesis of α1→6-mannooligosaccharides in Mycobacterium smegmatis. Function of β-mannosylphosphoryldecaprenol as the mannosyl donor. J. Biol. Chem. 264 (1989) 21621–21628. [PMID: 2480954]
[EC 2.4.1.199 created 1992]
 
 
EC 3.4.21.12     Relevance: 18%
Accepted name: α-lytic endopeptidase
Reaction: Preferential cleavage: Ala┼, Val┼ in bacterial cell walls, elastin and other proteins
Other name(s): myxobacter α-lytic proteinase; α-lytic proteinase; α-lytic protease; Mycobacterium sorangium α-lytic proteinase; Myxobacter 495 α-lytic proteinase; α-lytic proteinase; Myxobacter α-lytic proteinase; Mycobacterium sorangium α-lytic proteinase
Comments: From the myxobacterium Lysobacter enzymogenes. In peptidase family S1 (trypsin family)
References:
1.  Olson, M.O.J., Nagabushan, N., Dzwiniel, M., Smillie, L.B. and Whitaker, D.R. Primary structure of α-lytic protease: a bacterial homologue of the pancreatic serine proteases. Nature 228 (1970) 438–442. [PMID: 5482494]
2.  Polgár, L. Structure and function of serine proteases. In: Neuberger, A. and Brocklehurst, K. (Ed.), New Comprehensive Biochemistry: Hydrolytic Enzymes, vol. 16, Elsevier, Amsterdam, 1987, pp. 159–200.
3.  Epstein, D.M. and Wensink, P.C. The α-lytic protease gene of Lysobacter enzymogenes. The nucleotide sequence predicts a large prepro-peptide with homology to pro-peptides of other chymotrypsin-like enzymes. J. Biol. Chem. 263 (1988) 16586–16590. [PMID: 3053694]
4.  Bone, R., Frank, D., Kettner, C.A. and Agard, D.A. Structural analysis of specificity: α-lytic protease complexes with analogues of reaction intermediates. Biochemistry 28 (1989) 7600–7609. [PMID: 2611204]
[EC 3.4.21.12 created 1972]
 
 
EC 2.4.1.232     Relevance: 17.9%
Accepted name: initiation-specific α-1,6-mannosyltransferase
Reaction: Transfers an α-D-mannosyl residue from GDP-mannose into lipid-linked oligosaccharide, forming an α-(1→6)-D-mannosyl-D-mannose linkage
Other name(s): α-1,6-mannosyltransferase; GDP-mannose:oligosaccharide 1,6-α-D-mannosyltransferase; GDP-mannose:glycolipid 1,6-α-D-mannosyltransferase; glycolipid 6-α-mannosyltransferase; GDP-mannose:oligosaccharide 1,6-α-D-mannosyltransferase
Systematic name: GDP-mannose:oligosaccharide 6-α-D-mannosyltransferase
Comments: Requires Mn2+. In Saccharomyces cerevisiae, this enzyme catalyses an essential step in the outer chain elongation of N-linked oligosaccharides. Man8GlcNAc and Man9GlcNAc are equally good substrates.
References:
1.  Romero, P.A. and Herscovics, A. Glycoprotein biosynthesis in Saccharomyces cerevisiae. Characterization of α-1,6-mannosyltransferase which initiates outer chain formation. J. Biol. Chem. 264 (1989) 1946–1950. [PMID: 2644248]
2.  Reason, A.J., Dell, A., Romero, P.A. and Herscovics, A. Specificity of the mannosyltransferase which initiates outer chain formation in Saccharomyces cerevisiae. Glycobiology 1 (1991) 387–391. [PMID: 1820199]
3.  Nakanishi-Shindo, Y., Nakayama, K., Tanaka, A., Toda, Y. and Jigami, Y. Structure of the N-linked oligosaccharides that show the complete loss of α-1,6-polymannose outer chain from och1, och1 mnn1, and och1 mnn1 alg3 mutants of Saccharomyces cerevisiae. J. Biol. Chem. 268 (1993) 26338–26345. [PMID: 8253757]
4.  Yamamoto, K., Okamoto, M., Yoko-o, T. and Jigami, Y. Salt stress induces the expression of the Schizosaccharomyces pombe och1+, which encodes an initiation-specific α-1,6-mannosyltransferase for N-linked outer chain synthesis of cell wall mannoproteins. Biosci. Biotechnol. Biochem. 67 (2003) 927–929. [PMID: 12784644]
5.  Cui, Z., Horecka, J. and Jigami, Y. Cdc4 is involved in the transcriptional control of OCH1, a gene encoding α-1,6-mannosyltransferase in Saccharomyces cerevisiae. Yeast 19 (2002) 69–77. [PMID: 11754484]
6.  Tsukahara, K., Watanabe, T., Yoko-o, T. and Chigami, Y. Schizosaccharomyces pombe och1+ gene encoding α-1,6-mannosyltransferase and use of och1+ gene knockout fission yeast for production of glycoproteins with reduced glycosylation. Jpn. Kokai Tokkyo Koho Koho (2001) 11.
7.  Nakayama, K., Nakanishi-Shindo, Y., Tanaka, A., Haga-Toda, Y. and Jigami, Y. Substrate specificity of α-1,6-mannosyltransferase that initiates N-linked mannose outer chain elongation in Saccharomyces cerevisiae. FEBS Lett. 412 (1997) 547–550. [PMID: 9276464]
8.  Suzuki, A., Shibata, N., Suzuki, M., Saitoh, F., Takata, Y., Oshie, A., Oyamada, H., Kobayashi, H., Suzuki, S. and Okawa, Y. Characterization of α-1,6-mannosyltransferase responsible for the synthesis of branched side chains in Candida albicans mannan. Eur. J. Biochem. 240 (1996) 37–44. [PMID: 8797833]
9.  Yip, C.L., Welch, S.K., Klebl, F., Gilbert, T., Seidel, P., Grant, F., O'Hara, P.J. and MacKay, V.L. Cloning and analysis of the Saccharomyces cerevisiae MNN9 and MNN1 genes required for complex glycosylation of secreted proteins. Proc. Natl. Acad. Sci. USA 91 (1994) 2723–2727. [PMID: 8146181]
[EC 2.4.1.232 created 2004]
 
 
EC 2.4.99.7      
Transferred entry: α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase. Now EC 2.4.3.7, α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase
[EC 2.4.99.7 created 1984, modified 1986, modified 2004, deleted 2022]
 
 
EC 5.4.99.65     Relevance: 17.9%
Accepted name: pre-α-onocerin synthase
Reaction: (3S,22S)-2,3:22,23-diepoxy-2,3,22,23-tetrahydrosqualene = pre-α-onocerin
Glossary: pre-α-onocerin = (21S)-21,22-epoxypolypoda-8(26)-13,17-trien-3β-ol
Other name(s): LCC
Systematic name: (3S,22S)-2,3:22,23-diepoxy-2,3,22,23-tetrahydrosqualene mutase (cyclizing, pre-α-onocerin-forming)
Comments: Isolated from the plant Lycopodium clavatum. The enzyme does not act on (3S)-2,3-epoxy-2,3-dihydrosqualene and does not form any α-onocerin.
References:
1.  Araki, T., Saga, Y., Marugami, M., Otaka, J., Araya, H., Saito, K., Yamazaki, M., Suzuki, H. and Kushiro, T. Onocerin biosynthesis requires two highly dedicated triterpene cyclases in a fern Lycopodium clavatum. ChemBioChem 17 (2016) 288–290. [PMID: 26663356]
[EC 5.4.99.65 created 2017]
 
 
EC 2.4.1.377     Relevance: 17.9%
Accepted name: dTDP-Rha:α-D-Gal-diphosphoundecaprenol α-1,3-rhamnosyltransferase
Reaction: dTDP-β-L-rhamnose + α-D-galactosyl-diphospho-ditrans,octacis-undecaprenol = dTDP + α-L-Rha-(1→3)-α-D-Gal-PP-Und
Glossary: α-L-Rha-(1→3)-α-D-Gal-PP-Und = α-L-rhamnopyranosyl-(1→3)-α-D-galactopyranosyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): wbaN (gene name); rfbN (gene name)
Systematic name: dTDP-β-L-rhamnose:α-D-galactosyl-diphospho-ditrans,octacis-undecaprenol 3-α-rhamnosyltransferase (configuration-inverting)
Comments: The enzyme, characterized from several Salmonella strains, participates in the biosynthesis of the repeat unit of O antigens produced by strains that belong to the A, B, D and E groups.
References:
1.  Liu, D., Haase, A.M., Lindqvist, L., Lindberg, A.A. and Reeves, P.R. Glycosyl transferases of O-antigen biosynthesis in Salmonella enterica: identification and characterization of transferase genes of groups B, C2, and E1. J. Bacteriol. 175 (1993) 3408–3413. [PMID: 7684736]
[EC 2.4.1.377 created 2021]
 
 
EC 2.4.1.349     Relevance: 17.9%
Accepted name: mannosyl-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 3-α-mannosyltransferase
Reaction: 2 GDP-α-D-mannose + α-D-mannosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = 2 GDP + α-D-mannosyl-(1→3)-α-D-mannosyl-(1→3)-α-D-mannosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbdB
Systematic name: GDP-α-D-mannose:α-D-mannosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 3-α-mannosyltransferase (configuration-retaining)
Comments: The enzyme is involved in the biosynthesis of the linker region of the polymannose O-polysaccharide in the outer leaflet of the membrane of Escherichia coli serotypes O8, O9 and O9a. It has no activity with N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol (cf. EC 2.4.1.348, N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 3-α-mannosyltransferase).
References:
1.  Greenfield, L.K., Richards, M.R., Li, J., Wakarchuk, W.W., Lowary, T.L. and Whitfield, C. Biosynthesis of the polymannose lipopolysaccharide O-antigens from Escherichia coli serotypes O8 and O9a requires a unique combination of single- and multiple-active site mannosyltransferases. J. Biol. Chem. 287 (2012) 35078–35091. [PMID: 22875852]
[EC 2.4.1.349 created 2017]
 
 
EC 2.4.1.346     Relevance: 17.9%
Accepted name: phosphatidyl-myo-inositol dimannoside synthase
Reaction: (1) GDP-α-D-mannose + 2-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol = GDP + 2,6-di-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol
(2) GDP-α-D-mannose + 2-O-(6-O-acyl-α-D-mannosyl)-1-phosphatidyl-1D-myo-inositol = GDP + 2-O-(6-O-acyl-α-D-mannosyl)-6-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol
Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns
Other name(s): mannosyltransferase PimB; PimB; guanosine diphosphomannose-phosphatidyl-inositol α-mannosyltransferase (ambiguous)
Systematic name: GDP-α-D-mannose:2-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol 6-α-D-mannosyltransferase (configuration-retaining)
Comments: Requires Mg2+. The enzyme, found in Corynebacteriales, is involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs).
References:
1.  Guerin, M.E., Kaur, D., Somashekar, B.S., Gibbs, S., Gest, P., Chatterjee, D., Brennan, P.J. and Jackson, M. New insights into the early steps of phosphatidylinositol mannoside biosynthesis in mycobacteria: PimB′ is an essential enzyme of Mycobacterium smegmatis. J. Biol. Chem. 284 (2009) 25687–25696. [PMID: 19638342]
2.  Mishra, A.K., Batt, S., Krumbach, K., Eggeling, L. and Besra, G.S. Characterization of the Corynebacterium glutamicum Δ pimB′ Δ mgtA double deletion mutant and the role of Mycobacterium tuberculosis orthologues Rv2188c and Rv0557 in glycolipid biosynthesis. J. Bacteriol. 191 (2009) 4465–4472. [PMID: 19395496]
3.  Batt, S.M., Jabeen, T., Mishra, A.K., Veerapen, N., Krumbach, K., Eggeling, L., Besra, G.S. and Futterer, K. Acceptor substrate discrimination in phosphatidyl-myo-inositol mannoside synthesis: structural and mutational analysis of mannosyltransferase Corynebacterium glutamicum PimB′. J. Biol. Chem. 285 (2010) 37741–37752. [PMID: 20843801]
[EC 2.4.1.346 created 2017]
 
 
EC 2.4.99.3      
Transferred entry: α-N-acetylgalactosaminide α-2,6-sialyltransferase. Now EC 2.4.3.3, α-N-acetylgalactosaminide α-2,6-sialyltransferase
[EC 2.4.99.3 created 1984, modified 1986, deleted 2022]
 
 
EC 3.2.1.131     Relevance: 17.8%
Accepted name: xylan α-1,2-glucuronosidase
Reaction: Hydrolysis of (1→2)-α-D-(4-O-methyl)glucuronosyl links in the main chain of hardwood xylans
Other name(s): 1,2-α-glucuronidase; α-(1→2)-glucuronidase; xylan α-D-1,2-(4-O-methyl)glucuronohydrolase
Systematic name: xylan 2-α-D-(4-O-methyl)glucuronohydrolase
References:
1.  Ishihara, M. and Shimizu, K. α-(1→2)-Glucuronidase in the enzymatic saccharification of hardwood xylan .1. Screening of α-glucuronidase producing fungi. Mokuzai Gakkaishi 34 (1988) 58–64.
[EC 3.2.1.131 created 1990]
 
 
EC 2.4.1.308     Relevance: 17.8%
Accepted name: GDP-Fuc:β-D-Gal-1,3-α-D-GalNAc-1,3-α-GalNAc-diphosphoundecaprenol α-1,2-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-Gal-(1→3)-α-D-GalNAc-(1→3)-α-D-GalNAc-diphospho-ditrans,octacis-undecaprenol = GDP + α-L-Fuc-(1→2)-β-D-Gal-(1→3)-α-D-GalNAc-(1→3)-α-D-GalNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbnK
Systematic name: GDP-β-L-fucose:β-D-Gal-(1→3)-α-D-GalNAc-(1→3)-α-D-GalNAc-diphospho-ditrans,octacis-undecaprenol α-1,2-fucosyltransferase
Comments: The enzyme is involved in the biosynthesis of the O-polysaccharide repeating unit of the bacterium Escherichia coli serotype O86.
References:
1.  Yi, W., Shao, J., Zhu, L., Li, M., Singh, M., Lu, Y., Lin, S., Li, H., Ryu, K., Shen, J., Guo, H., Yao, Q., Bush, C.A. and Wang, P.G. Escherichia coli O86 O-antigen biosynthetic gene cluster and stepwise enzymatic synthesis of human blood group B antigen tetrasaccharide. J. Am. Chem. Soc. 127 (2005) 2040–2041. [PMID: 15713070]
2.  Woodward, R., Yi, W., Li, L., Zhao, G., Eguchi, H., Sridhar, P.R., Guo, H., Song, J.K., Motari, E., Cai, L., Kelleher, P., Liu, X., Han, W., Zhang, W., Ding, Y., Li, M. and Wang, P.G. In vitro bacterial polysaccharide biosynthesis: defining the functions of Wzy and Wzz. Nat. Chem. Biol. 6 (2010) 418–423. [PMID: 20418877]
[EC 2.4.1.308 created 2013]
 
 
EC 2.4.1.270     Relevance: 17.7%
Accepted name: mannosylglucosyl-3-phosphoglycerate synthase
Reaction: GDP-mannose + 2-O-(α-D-glucopyranosyl)-3-phospho-D-glycerate = GDP + 2-O-[2-O-(α-D-mannopyranosyl)-α-D-glucopyranosyl]-3-phospho-D-glycerate
Other name(s): MggA
Systematic name: GDP-mannose:2-O-(α-D-glucosyl)-3-phospho-D-glycerate 2-O-α-D-mannosyltransferase
Comments: The enzyme is involved in synthesis of 2-[2-O-(α-D-mannopranosyl)-α-D-glucopyranosyl]-D-glycerate. Petrotoga miotherma and Petrotoga mobilis accumulate this compound in response to water stress imposed by salt.
References:
1.  Fernandes, C., Mendes, V., Costa, J., Empadinhas, N., Jorge, C., Lamosa, P., Santos, H. and da Costa, M.S. Two alternative pathways for the synthesis of the rare compatible solute mannosylglucosylglycerate in Petrotoga mobilis. J. Bacteriol. 192 (2010) 1624–1633. [PMID: 20061481]
[EC 2.4.1.270 created 2011]
 
 
EC 3.2.1.122     Relevance: 17.7%
Accepted name: maltose-6′-phosphate glucosidase
Reaction: α-maltose 6′-phosphate + H2O = D-glucose + D-glucose 6-phosphate
Other name(s): phospho-α-glucosidase; maltose-6′-phosphate 6-phosphoglucohydrolase
Systematic name: α-maltose-6′-phosphate 6-phosphoglucohydrolase
Comments: Hydrolyses a variety of 6-phospho-α-D-glucosides, including α-maltose 6′-phosphate, α,α-trehalose 6-phosphate, sucrose 6-phosphate and p-nitrophenyl-α-D-glucopyranoside 6-phosphate (as a chromogenic substrate). The enzyme is activated by FeII, MnII, CoII and NiII. It is rapidly inactivated in air.
References:
1.  Thompson, J., Gentry-Weeks, C.R., Nguyen, N.Y., Folk, J.E., Robrish, S.A. Purification from Fusobacterium mortiferum ATCC 25557 of a 6-phosphoryl-O-α-D-glucopyranosyl:6-phosphoglucohydrolase that hydrolyses maltose 6-phosphate and related phospho-α-D-glucosides. J. Bacteriol. 177 (1995) 2505–2512. [PMID: 7730284]
[EC 3.2.1.122 created 1989, modified 1999]
 
 
EC 5.4.99.40     Relevance: 17.6%
Accepted name: α-amyrin synthase
Reaction: (3S)-2,3-epoxy-2,3-dihydrosqualene = α-amyrin
Other name(s): 2,3-oxidosqualene α-amyrin cyclase; mixed amyrin synthase
Systematic name: (3S)-2,3-epoxy-2,3-dihydrosqualene mutase (cyclizing, α-amyrin-forming)
Comments: A multifunctional enzyme which produces both α- and β-amyrin (see EC 5.4.99.39, β-amyrin synthase).
References:
1.  Morita, M., Shibuya, M., Kushiro, T., Masuda, K. and Ebizuka, Y. Molecular cloning and functional expression of triterpene synthases from pea (Pisum sativum) new α-amyrin-producing enzyme is a multifunctional triterpene synthase. Eur. J. Biochem. 267 (2000) 3453–3460. [PMID: 10848960]
[EC 5.4.99.40 created 2011]
 
 
EC 2.4.1.343     Relevance: 17.6%
Accepted name: UDP-Gal:α-D-GlcNAc-diphosphoundecaprenol α-1,3-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = UDP + α-D-Gal-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): wclR (gene name)
Systematic name: UDP-α-D-galactose:N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 3-α-galactosyltransferase (configuration-retaining)
Comments: The enzyme is involved in the the biosynthesis of the O-antigen repeating unit of Escherichia coli O3. Requires a divalent metal ion (Mn2+, Mg2+ or Fe2+). cf. EC 2.4.1.303, UDP-Gal:α-D-GlcNAc-diphosphoundecaprenol β-1,3-galactosyltransferase.
References:
1.  Chen, C., Liu, B., Xu, Y., Utkina, N., Zhou, D., Danilov, L., Torgov, V., Veselovsky, V. and Feng, L. Biochemical characterization of the novel α-1, 3-galactosyltransferase WclR from Escherichia coli O3. Carbohydr. Res. 430 (2016) 36–43. [PMID: 27196310]
[EC 2.4.1.343 created 2017]
 
 
EC 2.4.1.307      
Deleted entry: UDP-Gal:α-D-GalNAc-1,3-α-D-GalNAc-diphosphoundecaprenol β-1,3-galactosyltransferase. Now included in EC 2.4.1.122, glycoprotein-N-acetylgalactosamine β-1,3-galactosyltransferase
[EC 2.4.1.307 created 2013, deleted 2016]
 
 
EC 2.4.1.19     Relevance: 17.6%
Accepted name: cyclomaltodextrin glucanotransferase
Reaction: Cyclizes part of a (1→4)-α-D-glucan chain by formation of a (1→4)-α-D-glucosidic bond
Other name(s): Bacillus macerans amylase; cyclodextrin glucanotransferase; α-cyclodextrin glucanotransferase; α-cyclodextrin glycosyltransferase; β-cyclodextrin glucanotransferase; β-cyclodextrin glycosyltransferase; γ-cyclodextrin glycosyltransferase; cyclodextrin glycosyltransferase; cyclomaltodextrin glucotransferase; cyclomaltodextrin glycosyltransferase; konchizaimu; α-1,4-glucan 4-glycosyltransferase, cyclizing; BMA; CGTase; neutral-cyclodextrin glycosyltransferase; 1,4-α-D-glucan 4-α-D-(1,4-α-D-glucano)-transferase (cyclizing)
Systematic name: (1→4)-α-D-glucan:(1→4)-α-D-glucan 4-α-D-[(1→4)-α-D-glucano]-transferase (cyclizing)
Comments: Cyclomaltodextrins (Schardinger dextrins) of various sizes (6,7,8, etc. glucose units) are formed reversibly from starch and similar substrates. Will also disproportionate linear maltodextrins without cyclizing (cf. EC 2.4.1.25, 4-α-glucanotransferase).
References:
1.  DePinto, J.A. and Campbell, L.L. Purification and properties of the amylase of Bacillus macerans. Biochemistry 7 (1968) 114–120. [PMID: 5758537]
2.  French, D., Levine, M.L., Norberg, E., Norden, P., Pazur, J.H. and Wild, G.M. Studies on the Schardinger dextrins. VII. Co-substrate specificity in coupling reactions of Macerans amylase. J. Am. Chem. Soc. 76 (1954) 2387–2390.
3.  Hehre, E.J. Enzymic synthesis of polysaccharides: a biological type of polymerization. Adv. Enzymol. Relat. Subj. Biochem. 11 (1951) 297–337. [PMID: 24540594]
4.  Schwimmer, S. Evidence for the purity of Schardinger dextrinogenase. Arch. Biochem. Biophys. 43 (1953) 108–117. [PMID: 13031665]
[EC 2.4.1.19 created 1961]
 
 
EC 4.2.3.81     Relevance: 17.6%
Accepted name: exo-α-bergamotene synthase
Reaction: (2E,6E)-farnesyl diphosphate = (-)-exo-α-bergamotene + diphosphate
Glossary: (-)-exo-α-bergamotene = (-)-trans-α-bergamotene = (1S,5S,6R)-2,6-dimethyl-6-(4-methylpent-3-en-1-yl)bicyclo[3.1.1]hept-2-ene
Other name(s): trans-α-bergamotene synthase; LaBERS (gene name)
Systematic name: (2E,6E)-farnesyl diphosphate lyase (cyclizing, (-)-exo-α-bergamotene-forming)
Comments: The enzyme synthesizes a mixture of sesquiterpenoids from (2E,6E)-farnesyl diphosphate. As well as (-)-exo-α-bergamotene (74%) there were (E)-nerolidol (10%), (Z)-α-bisabolene (6%), (E)-β-farnesene (5%) and β-sesquiphellandrene (1%).
References:
1.  Schnee, C., Kollner, T.G., Held, M., Turlings, T.C., Gershenzon, J. and Degenhardt, J. The products of a single maize sesquiterpene synthase form a volatile defense signal that attracts natural enemies of maize herbivores. Proc. Natl. Acad. Sci. USA 103 (2006) 1129–1134. [PMID: 16418295]
2.  Landmann, C., Fink, B., Festner, M., Dregus, M., Engel, K.H. and Schwab, W. Cloning and functional characterization of three terpene synthases from lavender (Lavandula angustifolia). Arch. Biochem. Biophys. 465 (2007) 417–429. [PMID: 17662687]
[EC 4.2.3.81 created 2011]
 
 
EC 3.2.1.204     Relevance: 17.6%
Accepted name: 1,3-α-isomaltosidase
Reaction: cyclobis-(1→6)-α-nigerosyl + 2 H2O = 2 isomaltose (overall reaction)
(1a) cyclobis-(1→6)-α-nigerosyl + H2O = α-isomaltosyl-(1→3)-isomaltose
(1b) α-isomaltosyl-(1→3)-isomaltose + H2O = 2 isomaltose
Systematic name: 1,3-α-isomaltohydrolase (configuration-retaining)
Comments: The enzyme, characterized from the bacteria Bacillus sp. NRRL B-21195 and Kribbella flavida, participates in the degradation of starch. The cyclic tetrasaccharide cyclobis-(1→6)-α-nigerosyl is formed from starch extracellularly and imported into the cell, where it is degraded to glucose.
References:
1.  Kim, Y.K., Kitaoka, M., Hayashi, K., Kim, C.H. and Cote, G.L. Purification and characterization of an intracellular cycloalternan-degrading enzyme from Bacillus sp. NRRL B-21195. Carbohydr. Res. 339 (2004) 1179–1184. [PMID: 15063208]
2.  Tagami, T., Miyano, E., Sadahiro, J., Okuyama, M., Iwasaki, T. and Kimura, A. Two novel glycoside hydrolases responsible for the catabolism of cyclobis-(1→6)-α-nigerosyl. J. Biol. Chem. 291 (2016) 16438–16447. [PMID: 27302067]
[EC 3.2.1.204 created 2017]
 
 
EC 2.4.3.3     Relevance: 17.6%
Accepted name: α-N-acetylgalactosaminide α-2,6-sialyltransferase
Reaction: CMP-N-acetylneuraminate + glycano-(1→3)-(N-acetyl-α-D-galactosaminyl)-glycoprotein = CMP + glycano-[(2→6)-α-N-acetylneuraminyl]-(N-acetyl-D-galactosaminyl)-glycoprotein
Systematic name: CMP-N-acetylneuraminate:glycano-1,3-(N-acetyl-α-D-galactosaminyl)-glycoprotein α-2,6-N-acetylneuraminyltransferase
Comments: N-acetyl-α-D-galactosamine linked to threonine or serine is also an acceptor, when substituted at the 3-position.
References:
1.  Sadler, J.E., Rearick, J.I. and Hill, R.L. Purification to homogeneity and enzymatic characterization of an α-N-acetylgalactosaminide α2→6 sialyltransferase from porcine submaxillary glands. J. Biol. Chem. 254 (1979) 5934–5941. [PMID: 447688]
[EC 2.4.3.3 created 1984 as EC 2.4.99.3, modified 1986, transferred 2022 to EC 2.4.3.3]
 
 
EC 3.2.1.40     Relevance: 17.6%
Accepted name: α-L-rhamnosidase
Reaction: Hydrolysis of terminal non-reducing α-L-rhamnose residues in α-L-rhamnosides
Other name(s): α-L-rhamnosidase T; α-L-rhamnosidase N
Systematic name: α-L-rhamnoside rhamnohydrolase
Comments: The enzyme, found in animal tissues, plants, yeasts, fungi and bacteria, utilizes an inverting mechanism of hydrolysis, releasing β-L-rhamnose. Substrates include naringin, rutin, quercitrin, hesperidin, dioscin, terpenyl glycosides and many other natural glycosides containing terminal α-L-rhamnose.
References:
1.  Rosenfeld, E. and Wiederschein, G. The metabolism of L-rhamnose in animal tissues. Bull. Soc. Chim. Biol. 47 (1965) 1433–1440. [PMID: 5855461]
2.  Kurosawa, Y., Ikeda, K. and Egami, F. α-L-rhamnosidases of the liver of Turbo cornutus and Aspergillus niger. J. Biochem. 73 (1973) 31–37. [PMID: 4632197]
3.  Zverlov, V.V., Hertel, C., Bronnenmeier, K., Hroch, A., Kellermann, J. and Schwarz, W.H. The thermostable α-L-rhamnosidase RamA of Clostridium stercorarium: biochemical characterization and primary structure of a bacterial α-L-rhamnoside hydrolase, a new type of inverting glycoside hydrolase. Mol. Microbiol. 35 (2000) 173–179. [PMID: 10632887]
4.  Yanai, T. and Sato, M. Purification and characterization of an α-L-rhamnosidase from Pichia angusta X349. Biosci. Biotechnol. Biochem. 64 (2000) 2179–2185. [PMID: 11129592]
5.  Cui, Z., Maruyama, Y., Mikami, B., Hashimoto, W. and Murata, K. Crystal structure of glycoside hydrolase family 78 α-L-Rhamnosidase from Bacillus sp. GL1. J. Mol. Biol. 374 (2007) 384–398. [PMID: 17936784]
6.  Rabausch, U., Ilmberger, N. and Streit, W.R. The metagenome-derived enzyme RhaB opens a new subclass of bacterial B type α-L-rhamnosidases. J. Biotechnol. 191 (2014) 38–45. [PMID: 24815685]
[EC 3.2.1.40 created 1972]
 
 
EC 2.4.1.264     Relevance: 17.6%
Accepted name: D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphosphoundecaprenol 2-β-glucuronosyltransferase
Reaction: UDP-α-D-glucuronate + α-D-Man-(1→3)-β-D-Glc-(1→4)-α-D-Glc-1-diphospho-ditrans,octacis-undecaprenol = UDP + β-D-GlcA-(1→2)-α-D-Man-(1→3)-β-D-Glc-(1→4)-α-D-Glc-1-diphospho-ditrans,octacis-undecaprenol
Other name(s): GumK; UDP-glucuronate:D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphospho-ditrans,octacis-undecaprenol β-1,2-glucuronyltransferase; D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphosphoundecaprenol 2-β-glucuronyltransferase
Systematic name: UDP-α-D-glucuronate:α-D-Man-(1→3)-β-D-Glc-(1→4)-α-D-Glc-1-diphospho-ditrans,octacis-undecaprenol β-1,2-glucuronosyltransferase (configuration-inverting)
Comments: The enzyme is involved in the biosynthesis of the exopolysaccharides xanthan (in the bacterium Xanthomonas campestris) and acetan (in the bacterium Gluconacetobacter xylinus).
References:
1.  Katzen, F., Ferreiro, D.U., Oddo, C.G., Ielmini, M.V., Becker, A., Puhler, A. and Ielpi, L. Xanthomonas campestris pv. campestris gum mutants: effects on xanthan biosynthesis and plant virulence. J. Bacteriol. 180 (1998) 1607–1617. [PMID: 9537354]
2.  Ielpi, L., Couso, R.O. and Dankert, M.A. Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris. J. Bacteriol. 175 (1993) 2490–2500. [PMID: 7683019]
3.  Kim, S.Y., Kim, J.G., Lee, B.M. and Cho, J.Y. Mutational analysis of the gum gene cluster required for xanthan biosynthesis in Xanthomonas oryzae pv oryzae. Biotechnol. Lett. 31 (2009) 265–270. [PMID: 18854951]
4.  Barreras, M., Bianchet, M.A. and Ielpi, L. Crystallization and preliminary crystallographic characterization of GumK, a membrane-associated glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 62 (2006) 880–883. [PMID: 16946469]
5.  Barreras, M., Salinas, S.R., Abdian, P.L., Kampel, M.A. and Ielpi, L. Structure and mechanism of GumK, a membrane-associated glucuronosyltransferase. J. Biol. Chem. 283 (2008) 25027–25035. [PMID: 18596046]
6.  Vojnov, A.A., Bassi, D.E., Daniels, M.J. and Dankert, M.A. Biosynthesis of a substituted cellulose from a mutant strain of Xanthomonas campestris. Carbohydr. Res. 337 (2002) 315–326. [PMID: 11841812]
7.  Barreras, M., Abdian, P.L. and Ielpi, L. Functional characterization of GumK, a membrane-associated β-glucuronosyltransferase from Xanthomonas campestris required for xanthan polysaccharide synthesis. Glycobiology 14 (2004) 233–241. [PMID: 14736729]
[EC 2.4.1.264 created 2011, modified 2016]
 
 
EC 4.2.3.90     Relevance: 17.5%
Accepted name: 5-epi-α-selinene synthase
Reaction: (2E,6E)-farnesyl diphosphate = 5-epi-α-selinene + diphosphate
Glossary: 5-epi-α-selinene = 5β-eudesma-3,11-diene = (2R,4aR,8aS)-1,2,3,4,4a,5,6,8a-octahydro-4a,8-dimethyl-2-(prop-1-en-2-yl)naphthalene;;
[= 8a-epi-α-selinene which uses naththalene numbering not eudesmane]
Other name(s): 8a-epi-α-selinene synthase; NP1
Systematic name: (2Z,6E)-farnesyl-diphosphate diphosphate-lyase (cyclizing, 5-epi-α-selinene-forming)
Comments: Requires Mg2+. The enzyme forms 5-epi-α-selinene possibly via germecrene A or a 1,6-hydride shift mechanism.
References:
1.  Agger, S.A., Lopez-Gallego, F., Hoye, T.R. and Schmidt-Dannert, C. Identification of sesquiterpene synthases from Nostoc punctiforme PCC 73102 and Nostoc sp. strain PCC 7120. J. Bacteriol. 190 (2008) 6084–6096. [PMID: 18658271]
[EC 4.2.3.90 created 2011]
 
 
EC 1.1.1.187     Relevance: 17.5%
Accepted name: GDP-4-dehydro-D-rhamnose reductase
Reaction: (1) GDP-α-D-rhamnose + NAD(P)+ = GDP-4-dehydro-α-D-rhamnose + NAD(P)H + H+
(2) GDP-6-deoxy-α-D-talose + NAD(P)+ = GDP-4-dehydro-α-D-rhamnose + NAD(P)H + H+
Glossary: GDP-α-D-rhamnose = GDP-6-deoxy-α-D-mannose
GDP-4-dehydro-α-D-rhamnose = GDP-4-dehydro-6-deoxy-α-D-mannose
GDP-6-deoxy-α-D-talose = GDP-α-D-pneumose
Other name(s): GDP-4-keto-6-deoxy-D-mannose reductase; GDP-4-keto-D-rhamnose reductase; guanosine diphosphate-4-keto-D-rhamnose reductase; GDP-6-deoxy-D-mannose:NAD(P)+ 4-oxidoreductase; GDP-6-deoxy-α-D-mannose:NAD(P)+ 4-oxidoreductase
Systematic name: GDP-4-dehydro-α-D-rhamnose:NAD(P)+ 4-oxidoreductase
Comments: The enzyme, which operates in the opposite direction to that shown, forms a mixture of GDP-α-D-rhamnose and its C-4 epimer, GDP-6-deoxy-α-D-talose. cf. EC 1.1.1.281, GDP-4-dehydro-6-deoxy-D-mannose reductase and EC 1.1.1.135, GDP-6-deoxy-D-talose 4-dehydrogenase.
References:
1.  Barber, G.A. The synthesis of guanosine 5′-diphosphate D-rhamnose by enzymes of a higher plant. Biochim. Biophys. Acta 165 (1968) 68–75. [PMID: 4386238]
2.  Winkler, N.W. and Markovitz, A. Guanosine diphosphate-4-keto-D-rhamnose reductase. A non-stereoselective enzyme. J. Biol. Chem. 246 (1971) 5868–5876. [PMID: 4398966]
[EC 1.1.1.187 created 1984]
 
 
EC 5.1.3.23     Relevance: 17.5%
Accepted name: UDP-2,3-diacetamido-2,3-dideoxyglucuronic acid 2-epimerase
Reaction: UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronate = UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronate
Glossary: UDP-α-D-GlcNAc3NAcA = UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid
UDP-α-D-ManNAc3NAcA = UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronic acid
Other name(s): UDP-GlcNAc3NAcA 2-epimerase; UDP-α-D-GlcNAc3NAcA 2-epimerase; 2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerase; WbpI; WlbD
Systematic name: 2,3-diacetamido-2,3-dideoxy-α-D-glucuronate 2-epimerase
Comments: This enzyme participates in the biosynthetic pathway for UDP-α-D-ManNAc3NAcA (UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronic acid), an important precursor of the B-band lipopolysaccharide of Pseudomonas aeroginosa serotype O5 and of the band-A trisaccharide of Bordetella pertussis, both important respiratory pathogens [1]. The enzyme is highly specific as UDP-α-D-GlcNAc, UDP-α-D-GlcNAcA (UDP-2-acetamido-2-deoxy-α-D-glucuronic acid) and UDP-α-D-GlcNAc3NAc (UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucose) cannot act as substrates [1].
References:
1.  Westman, E.L., McNally, D.J., Rejzek, M., Miller, W.L., Kannathasan, V.S., Preston, A., Maskell, D.J., Field, R.A., Brisson, J.R. and Lam, J.S. Identification and biochemical characterization of two novel UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerases from respiratory pathogens. Biochem. J. 405 (2007) 123–130. [PMID: 17346239]
2.  Westman, E.L., McNally, D.J., Rejzek, M., Miller, W.L., Kannathasan, V.S., Preston, A., Maskell, D.J., Field, R.A., Brisson, J.R. and Lam, J.S. Erratum report: Identification and biochemical characterization of two novel UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronic acid 2-epimerases from respiratory pathogens. Biochem. J. 405 (2007) 625.
3.  Sri Kannathasan, V., Staines, A.G., Dong, C.J., Field, R.A., Preston, A.G., Maskell, D.J. and Naismith, J.H. Overexpression, purification, crystallization and data collection on the Bordetella pertussis wlbD gene product, a putative UDP-GlcNAc 2′-epimerase. Acta Crystallogr. D Biol. Crystallogr. 57 (2001) 1310–1312. [PMID: 11526328]
[EC 5.1.3.23 created 2007]
 
 
EC 2.3.1.108     Relevance: 17.5%
Accepted name: α-tubulin N-acetyltransferase
Reaction: acetyl-CoA + [α-tubulin]-L-lysine = CoA + [α-tubulin]-N6-acetyl-L-lysine
Other name(s): ATAT1 (gene name); MEC17 (gene name); α-tubulin acetylase; TAT; α-tubulin acetyltransferase; tubulin N-acetyltransferase (ambiguous); acetyl-CoA:α-tubulin-L-lysine N-acetyltransferase; acetyl-CoA:[α-tubulin]-L-lysine 6-N-acetyltransferase
Systematic name: acetyl-CoA:[α-tubulin]-L-lysine N6-acetyltransferase
Comments: The enzyme is conserved from protists to mammals and is present in flowering plants. In most organisms it acetylates L-lysine at position 40 of α-tubulin.
References:
1.  Greer, K., Maruta, H., L'Hernault, S.W. and Rosenbaum, J.L. α-Tubulin acetylase activity in isolated Chlamydomonas flagella. J. Cell Biol. 101 (1985) 2081–2084. [PMID: 4066751]
2.  Akella, J.S., Wloga, D., Kim, J., Starostina, N.G., Lyons-Abbott, S., Morrissette, N.S., Dougan, S.T., Kipreos, E.T. and Gaertig, J. MEC-17 is an α-tubulin acetyltransferase. Nature 467 (2010) 218–222. [PMID: 20829795]
3.  Shida, T., Cueva, J.G., Xu, Z., Goodman, M.B. and Nachury, M.V. The major α-tubulin K40 acetyltransferase αTAT1 promotes rapid ciliogenesis and efficient mechanosensation. Proc. Natl. Acad. Sci. USA 107 (2010) 21517–21522. [PMID: 21068373]
4.  Taschner, M., Vetter, M. and Lorentzen, E. Atomic resolution structure of human α-tubulin acetyltransferase bound to acetyl-CoA. Proc. Natl. Acad. Sci. USA 109 (2012) 19649–19654. [PMID: 23071318]
5.  Friedmann, D.R., Aguilar, A., Fan, J., Nachury, M.V. and Marmorstein, R. Structure of the α-tubulin acetyltransferase, αTAT1, and implications for tubulin-specific acetylation. Proc. Natl. Acad. Sci. USA 109 (2012) 19655–19660. [PMID: 23071314]
6.  Kalebic, N., Sorrentino, S., Perlas, E., Bolasco, G., Martinez, C. and Heppenstall, P.A. αTAT1 is the major α-tubulin acetyltransferase in mice. Nat. Commun. 4:1962 (2013). [PMID: 23748901]
[EC 2.3.1.108 created 1989, modified 2021]
 
 
EC 3.2.1.129     Relevance: 17.4%
Accepted name: endo-α-sialidase
Reaction: Endohydrolysis of (2→8)-α-sialosyl linkages in oligo- or poly(sialic) acids
Other name(s): endo-N-acylneuraminidase; endoneuraminidase; endo-N-acetylneuraminidase; poly(α-2,8-sialosyl) endo-N-acetylneuraminidase; poly(α-2,8-sialoside) α-2,8-sialosylhydrolase; endosialidase; endo-N
Systematic name: polysialoside (2→8)-α-sialosylhydrolase
Comments: Although the name endo-N-acetylneuraminidase has also been used for this enzyme, this is misleading since its activity is not restricted to acetylated substrates. An exo-α-sialidase activity is listed as EC 3.2.1.18 exo-α-sialidase. See also EC 4.2.2.15 anhydrosialidase.
References:
1.  Finne, J., Mäkelä, P.H. Cleavage of the polysialosyl units of brain glycoproteins by a bacteriophage endosialidase. Involvement of a long oligosaccharide segment in molecular interactions of polysialic acid. J. Biol. Chem. 260 (1985) 1265–1270. [PMID: 3968060]
2.  Hallenbeck, P.C., Vimr, E.R., Yu, F., Bassler, B. and Troy, F.A. Purification and properties of a bacteriophage-induced endo-N-acetylneuraminidase specific for poly-α-2,8-sialosyl carbohydrate units. J. Biol. Chem. 262 (1987) 3553–3561. [PMID: 3546309]
3.  Kitakima, K., Inoue, S., Inoue, Y. and Troy, F.A. Use of a bacteriophage-derived endo-N-acetylneuraminidase and an equine antipolysialyl antibody to characterize the polysialyl residues in salmonid fish egg polysialoglycoproteins. Substrate and immunospecificity studies. J. Biol. Chem. 263 (1988) 18269–18276. [PMID: 3142874]
4.  Kwiatkowski, B., Boscheck, B., Thicle, H. and Stirm, S. Endo-N-acetylneuraminidase associated with bacteriophage particles. J. Virol. 43 (1982) 697–704. [PMID: 7109038]
5.  Pelkonen, S., Pelkonen, J. and Finne, J. Common cleavage pattern of polysialic acid by bacteriophage endosialidases of different properties and origins. J. Virol. 65 (1989) 4409–4416. [PMID: 2778882]
6.  Tombinson, S. and Taylor, P.W. Neuraminidase associated with coliphage E that specifically depolymerizes the Escherichia coli K1 capsular polysaccharide. J. Virol. 55 (1985) 374–378. [PMID: 3894684]
7.  Cabezas, J.A. Some questions and suggestions on the type references of the official nomenclature (IUB) for sialidase(s) and endosialidase. Biochem. J. 278 (1991) 311–312. [PMID: 1883340]
[EC 3.2.1.129 created 1990, modified 1999]
 
 
EC 2.4.1.291     Relevance: 17.4%
Accepted name: N-acetylgalactosamine-N,N′-diacetylbacillosaminyl-diphospho-undecaprenol 4-α-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + N-acetyl-D-galactosaminyl-α-(1→3)-N,N′-diacetyl-α-D-bacillosaminyl-diphospho-tritrans,heptacis-undecaprenol = UDP + N-acetyl-D-galactosaminyl-α-(1→4)-N-acetyl-D-galactosaminyl-α-(1→3)-N,N′-diacetyl-α-D-bacillosaminyl-diphospho-tritrans,heptacis-undecaprenol
Glossary: N,N′-diacetyl-D-bacillosamine = 2,4-diacetamido-2,4,6-trideoxy-D-glucopyranose
Other name(s): PglJ
Systematic name: UDP-N-acetyl-α-D-galactosamine:N-acetylgalactosaminyl-α-(1→3)-N,N′-diacetyl-α-D-bacillosaminyl-diphospho-tritrans,heptacis-undecaprenol 3-α-N-acetyl-D-galactosaminyltransferase
Comments: Isolated from Campylobacter jejuni. Part of a bacterial N-linked glycosylation pathway.
References:
1.  Glover, K.J., Weerapana, E. and Imperiali, B. In vitro assembly of the undecaprenylpyrophosphate-linked heptasaccharide for prokaryotic N-linked glycosylation. Proc. Natl. Acad. Sci. USA 102 (2005) 14255–14259. [PMID: 16186480]
2.  Chen, M.M., Weerapana, E., Ciepichal, E., Stupak, J., Reid, C.W., Swiezewska, E. and Imperiali, B. Polyisoprenol specificity in the Campylobacter jejuni N-linked glycosylation pathway. Biochemistry 46 (2007) 14342–14348. [PMID: 18034500]
[EC 2.4.1.291 created 2012]
 
 
EC 2.4.1.37     Relevance: 17.4%
Accepted name: fucosylgalactoside 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + α-L-fucosyl-(1→2)-D-galactosyl-R = UDP + α-D-galactosyl-(1→3)-[α-L-fucosyl(1→2)]-D-galactosyl-R (where R can be OH, an oligosaccharide or a glycoconjugate)
Other name(s): UDP-galactose:O-α-L-fucosyl(1→2)D-galactose α-D-galactosyltransferase; UDPgalactose:glycoprotein-α-L-fucosyl-(1,2)-D-galactose 3-α-D-galactosyltransferase; [blood group substance] α-galactosyltransferase; blood-group substance B-dependent galactosyltransferase; glycoprotein-fucosylgalactoside α-galactosyltransferase; histo-blood group B transferase; histo-blood substance B-dependent galactosyltransferase; UDP-galactose:α-L-fucosyl-1,2-D-galactoside 3-α-D-galactosyltransferase; UDP-galactose:α-L-fucosyl-(1→2)-D-galactoside 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:α-L-fucosyl-(1→2)-D-galactoside 3-α-D-galactosyltransferase
Comments: Acts on blood group substance, and can use a number of 2-fucosyl-galactosides as acceptors.
References:
1.  Race, C., Ziderman, D. and Watkins, W.M. An α-D-galactosyltransferase associated with the blood-group B character. Biochem. J. 107 (1968) 733–735. [PMID: 16742598]
[EC 2.4.1.37 created 1972, modified 1999, modified 2002]
 
 
EC 1.14.13.155     Relevance: 17.4%
Accepted name: α-pinene monooxygenase
Reaction: (–)-α-pinene + NADH + H+ + O2 = α-pinene oxide + NAD+ + H2O
Systematic name: (–)-α-pinene,NADH:oxygen oxidoreductase
Comments: Involved in the catabolism of α-pinene.
References:
1.  Colocousi, A. Saqib, K.M. and Leak, D.J. Mutants of Pseudomonas fuorescence NCIMB 11671 defective in the catabolism of α-pinene. Appl. Microbiol. Biotechnol. 45 (1996) 822–830.
[EC 1.14.13.155 created 2012]
 
 
EC 2.4.1.44     Relevance: 17.4%
Accepted name: lipopolysaccharide 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + lipopolysaccharide = UDP + 3-α-D-galactosyl-[lipopolysaccharide glucose]
Other name(s): UDP-galactose:lipopolysaccharide α,3-galactosyltransferase; UDP-galactose:polysaccharide galactosyltransferase; uridine diphosphate galactose:lipopolysaccharide α-3-galactosyltransferase; uridine diphosphogalactose-lipopolysaccharide α,3-galactosyltransferase; UDP-galactose:lipopolysaccharide 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:lipopolysaccharide 3-α-D-galactosyltransferase
Comments: Transfers α-D-galactosyl residues to D-glucose in the partially completed core of lipopolysaccharide [cf. EC 2.4.1.56 (lipopolysaccharide N-acetylglucosaminyltransferase), EC 2.4.1.58 (lipopolysaccharide glucosyltransferase I) and EC 2.4.1.73 (lipopolysaccharide glucosyltransferase II)].
References:
1.  Endo, A. and Rothfield, L. Studies of a phospholipid-requiring bacterial enzyme. I. Purification and properties of uridine diphosphate galactose: lipopolysaccharide α-3-galactosyl transferase. Biochemistry 8 (1969) 3500–3507. [PMID: 4898284]
2.  Wollin, R., Creeger, E.S., Rothfield, L.I., Stocker, B.A.D. and Lindberg, A.A. Salmonella typhimurium mutants defective in UDP-D-galactose:lipopolysaccharide α-1,6-D-galactosyltransferase. Structural, immunochemical, and enzymologic studies of rfaB mutants. J. Biol. Chem. 258 (1983) 3769–3774. [PMID: 6403519]
[EC 2.4.1.44 created 1972, modified 2002]
 
 
EC 2.4.1.18     Relevance: 17.3%
Accepted name: 1,4-α-glucan branching enzyme
Reaction: Transfers a segment of a (1→4)-α-D-glucan chain to a primary hydroxy group in a similar glucan chain
Other name(s): branching enzyme; amylo-(1,4→1,6)-transglycosylase; Q-enzyme; α-glucan-branching glycosyltransferase; amylose isomerase; enzymatic branching factor; branching glycosyltransferase; enzyme Q; glucosan transglycosylase; glycogen branching enzyme; plant branching enzyme; α-1,4-glucan:α-1,4-glucan-6-glycosyltransferase; starch branching enzyme; 1,4-α-D-glucan:1,4-α-D-glucan 6-α-D-(1,4-α-D-glucano)-transferase
Systematic name: (1→4)-α-D-glucan:(1→4)-α-D-glucan 6-α-D-[(1→4)-α-D-glucano]-transferase
Comments: Converts amylose into amylopectin. The accepted name requires a qualification depending on the product, glycogen or amylopectin, e.g. glycogen branching enzyme, amylopectin branching enzyme. The latter has frequently been termed Q-enzyme.
References:
1.  Barker, S.A., Bourne, E. and Peat, S. The enzymic synthesis and degradation of starch. Part IV. The purification and storage of the Q-enzyme of the potato. J. Chem. Soc. (Lond.) (1949) 1705–1711.
2.  Baum, H. and Gilbert, G.A. A simple method for the preparation of crystalline potato phosphorylase and Q-enzyme. Nature 171 (1953) 983–984. [PMID: 13063502]
3.  Hehre, E.J. Enzymic synthesis of polysaccharides: a biological type of polymerization. Adv. Enzymol. Relat. Subj. Biochem. 11 (1951) 297–337. [PMID: 24540594]
4.  Illingworth Brown, B. and Brown, D.H. α-1,4-Glucan:α-1,4-glucan 6-glycosyltransferase from mammalian muscle. Methods Enzymol. 8 (1966) 395–403.
[EC 2.4.1.18 created 1961]
 
 
EC 1.1.1.426     Relevance: 17.3%
Accepted name: UDP-N-acetyl-α-D-quinovosamine dehydrogenase
Reaction: UDP-N-acetyl-α-D-quinovosamine + NAD(P)+ = UDP-2-acetamido-2,6-dideoxy-α-D-xylohex-4-ulose + NAD(P)H + H+
Glossary: UDP-N-acetyl-α-D-quinovosamine = UDP-N-acetyl-6-deoxy-α-D-glucosamine
Other name(s): wbpV (gene name); wreQ (gene name)
Systematic name: UDP-N-acetyl-α-D-quinovosamine:NAD(P)+ 4-dehydrogenase
Comments: The enzyme participates in the biosynthesis of N-acetyl-α-D-quinovosamine, a 6-deoxy sugar that is present in the O antigens of many Gram-negative bacteria, including Pseudomonas aeruginosa serotypes O6 and O10, Rhizobium etli, and Brucella abortus.
References:
1.  Belanger, M., Burrows, L.L. and Lam, J.S. Functional analysis of genes responsible for the synthesis of the B-band O antigen of Pseudomonas aeruginosa serotype O6 lipopolysaccharide. Microbiology (Reading) 145 (1999) 3505–3521. [PMID: 10627048]
2.  Forsberg, L.S., Noel, K.D., Box, J. and Carlson, R.W. Genetic locus and structural characterization of the biochemical defect in the O-antigenic polysaccharide of the symbiotically deficient Rhizobium etli mutant, CE166. Replacement of N-acetylquinovosamine with its hexosyl-4-ulose precursor. J. Biol. Chem. 278 (2003) 51347–51359. [PMID: 14551189]
3.  Li, T., Simonds, L., Kovrigin, E.L. and Noel, K.D. In vitro biosynthesis and chemical identification of UDP-N-acetyl-D-quinovosamine (UDP-D-QuiNAc). J. Biol. Chem. 289 (2014) 18110–18120. [PMID: 24817117]
[EC 1.1.1.426 created 2021]
 
 
EC 2.4.3.8     Relevance: 17.3%
Accepted name: α-N-acetylneuraminate α-2,8-sialyltransferase
Reaction: CMP-N-acetylneuraminate + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-R = CMP + α-N-acetylneuraminyl-(2→8)-α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-R
Other name(s): cytidine monophosphoacetylneuraminate-ganglioside GM3; α-2,8-sialyltransferase; ganglioside GD3 synthase; ganglioside GD3 synthetase sialyltransferase; CMP-NeuAc:LM1(α2-8) sialyltranferase; GD3 synthase; SAT-2
Systematic name: CMP-N-acetylneuraminate:α-N-acetylneuraminyl-(2→3)-β-D-galactoside α-(2→8)-N-acetylneuraminyltransferase
Comments: Gangliosides act as acceptors.
References:
1.  Eppler, M.C., Morré, J.D. and Keenan, T.W. Ganglioside biosynthesis in rat liver: alteration of sialyltransferase activities by nucleotides. Biochim. Biophys. Acta 619 (1980) 332–343. [PMID: 7407217]
2.  Higashi, H., Basu, M. and Basu, S. Biosynthesis in vitro of disialosylneolactotetraosylceramide by a solubilized sialyltransferase from embryonic chicken brain. J. Biol. Chem. 260 (1985) 824–828. [PMID: 3838172]
3.  McCoy, R.D., Vimr, E.R. and Troy, F.A. CMP-NeuNAc:poly-α-2,8-sialosyl sialyltransferase and the biosynthesis of polysialosyl units in neural cell adhesion molecules. J. Biol. Chem. 260 (1985) 12695–12699. [PMID: 4044605]
4.  Yohe, H.C. and Yu, R.K. In vitro biosynthesis of an isomer of brain trisialoganglioside, GT1a. J. Biol. Chem. 255 (1980) 608–613. [PMID: 6766128]
[EC 2.4.3.8 created 1984 as EC 2.4.99.8, modified 1986, transferred 2022 to EC 2.4.3.8]
 
 
EC 2.4.99.8      
Transferred entry: α-N-acetylneuraminate α-2,8-sialyltransferase. Now EC 2.4.3.8, α-N-acetylneuraminate α-2,8-sialyltransferase
[EC 2.4.99.8 created 1984, modified 1986, deleted 2022]
 
 
EC 3.2.1.98     Relevance: 17.3%
Accepted name: glucan 1,4-α-maltohexaosidase
Reaction: Hydrolysis of (1→4)-α-D-glucosidic linkages in amylaceous polysaccharides, to remove successive maltohexaose residues from the non-reducing chain ends
Other name(s): exo-maltohexaohydrolase; 1,4-α-D-glucan maltohexaohydrolase
Systematic name: 4-α-D-glucan maltohexaohydrolase
Comments: cf. EC 3.2.1.3 glucan 1,4-α-glucosidase, which removes successive glucose residues; EC 3.2.1.2 β-amylase, which removes successive maltose residues; EC 3.2.1.116 glucan 1,4-α-maltotriohydrolase, which removes successive maltotriose units and EC 3.2.1.60 glucan 1,4-α-maltotetraohydrolase, which removes successive maltotetraose residues. The products have the α-configuration.
References:
1.  Kainuma, K., Wako, K., Kobayashi, A., Nogami, A. and Suzuki, S. Purification and some properties of a novel maltohexaose-producing exo-amylase from Aerobacter aerogenes. Biochim. Biophys. Acta 410 (1975) 333–346. [PMID: 1094]
2.  Nakakuki, T., Azuma, K. and Kainuma, K. Action patterns of various exo-amylases and the anomeric configurations of their products. Carbohydr. Res. 128 (1984) 297–310.
[EC 3.2.1.98 created 1978]
 
 
EC 3.2.1.60     Relevance: 17.3%
Accepted name: glucan 1,4-α-maltotetraohydrolase
Reaction: Hydrolysis of (1→4)-α-D-glucosidic linkages in amylaceous polysaccharides, to remove successive maltotetraose residues from the non-reducing chain ends
Other name(s): exo-maltotetraohydrolase; 1,4-α-D-glucan maltotetraohydrolase
Systematic name: 4-α-D-glucan maltotetraohydrolase
Comments: Compare EC 3.2.1.2 β-amylase, which removes successive maltose residues, and EC 3.2.1.98 (glucan 1,4-α-maltohexaosidase) and EC 3.2.1.116 (glucan 1,4-α-maltotriohydrolase).
References:
1.  Nakakuki, T., Azuma, K. and Kainuma, K. Action patterns of various exo-amylases and the anomeric configurations of their products. Carbohydr. Res. 128 (1984) 297–310.
2.  Robyt, J.F. and Ackerman, R.J. Isolation, purification, and characterization of a maltotetraose-producing amylase from Pseudomonas stutzeri. Arch. Biochem. Biophys. 145 (1971) 105–114. [PMID: 5123132]
[EC 3.2.1.60 created 1972]
 
 
EC 3.1.1.43     Relevance: 17.3%
Accepted name: α-amino-acid esterase
Reaction: an α-amino acid ester + H2O = an α-amino acid + an alcohol
Other name(s): α-amino acid ester hydrolase
Systematic name: α-amino-acid-ester aminoacylhydrolase
Comments: Also catalyses α-aminoacyl transfer to a number of amine nucleophiles.
References:
1.  Kato, K., Kawahara, K., Takahashi, T. and Kakinuma, A. Purification of an α-amino acid ester hydrolase from Xanthomonas citri. Agric. Biol. Chem. 44 (1980) 1069–1074.
2.  Kato, K., Kawahara, K., Takahashi, T. and Kakinuma, A. Substrate specificity of an α-amino acid ester hydrolase from Xanthomonas citri. Agric. Biol. Chem. 44 (1980) 1075–1081.
3.  Takahashi, T., Yamazaki, Y. and Kato, K. Substrate specificity of an α-amino acid ester hydrolase produced by Acetobacter turbidans A. T.C.C. 9325. Biochem. J. 137 (1974) 497–503. [PMID: 4424889]
[EC 3.1.1.43 created 1983]
 
 
EC 2.4.1.306     Relevance: 17.3%
Accepted name: UDP-GalNAc:α-D-GalNAc-diphosphoundecaprenol α-1,3-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + N-acetyl-α-D-galactosaminyl-diphospho-ditrans,octacis-undecaprenol = UDP + α-D-GalNAc-(1→3)-α-D-GalNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbnH
Systematic name: UDP-N-acetyl-α-D-galactosamine:N-acetyl-α-D-galactosaminyl-diphospho-ditrans,octacis-undecaprenol α-1,3-N-acetyl-D-galactosyltransferase
Comments: The enzyme is involved in the the biosynthesis of the O-polysaccharide repeating unit of Escherichia coli serotype O86.
References:
1.  Yi, W., Yao, Q., Zhang, Y., Motari, E., Lin, S. and Wang, P.G. The wbnH gene of Escherichia coli O86:H2 encodes an α-1,3-N-acetylgalactosaminyl transferase involved in the O-repeating unit biosynthesis. Biochem. Biophys. Res. Commun. 344 (2006) 631–639. [PMID: 16630548]
[EC 2.4.1.306 created 2013]
 
 
EC 2.4.2.62     Relevance: 17.2%
Accepted name: xylosyl α-1,3-xylosyltransferase
Reaction: UDP-α-D-xylose + [protein with EGF-like domain]-3-O-[α-D-xylosyl-(1→3)-β-D-glucosyl]-L-serine = UDP + [protein with EGF-like domain]-3-O-[α-D-xylosyl-(1→3)-α-D-xylosyl-(1→3)-β-D-glucosyl]-L-serine
Other name(s): XXYLT1 (gene name)
Systematic name: UDP-α-D-xylose:[EGF-like domain protein]-3-O-[α-D-xylosyl-(1→3)-β-D-glucosyl]-L-serine 3-α-D-xylosyltransferase (configuration-retaining)
Comments: The enzyme, found in animals and insects, is involved in the biosynthesis of the α-D-xylosyl-(1→3)-α-D-xylosyl-(1→3)-β-D-glucosyl trisaccharide on epidermal growth factor-like (EGF-like) domains. When present on Notch proteins, the trisaccharide functions as a modulator of the signalling activity of this protein.
References:
1.  Minamida, S., Aoki, K., Natsuka, S., Omichi, K., Fukase, K., Kusumoto, S. and Hase, S. Detection of UDP-D-xylose: α-D-xyloside α 1-→3xylosyltransferase activity in human hepatoma cell line HepG2. J. Biochem. 120 (1996) 1002–1006. [PMID: 8982869]
2.  Sethi, M.K., Buettner, F.F., Ashikov, A., Krylov, V.B., Takeuchi, H., Nifantiev, N.E., Haltiwanger, R.S., Gerardy-Schahn, R. and Bakker, H. Molecular cloning of a xylosyltransferase that transfers the second xylose to O-glucosylated epidermal growth factor repeats of notch. J. Biol. Chem. 287 (2012) 2739–2748. [PMID: 22117070]
3.  Yu, H., Takeuchi, M., LeBarron, J., Kantharia, J., London, E., Bakker, H., Haltiwanger, R.S., Li, H. and Takeuchi, H. Notch-modifying xylosyltransferase structures support an SNi-like retaining mechanism. Nat. Chem. Biol. 11 (2015) 847–854. [PMID: 26414444]
[EC 2.4.2.62 created 2020]
 
 
EC 3.2.1.115     Relevance: 17.2%
Accepted name: branched-dextran exo-1,2-α-glucosidase
Reaction: Hydrolysis of (1→2)-α-D-glucosidic linkages at the branch points of dextrans and related polysaccharides, producing free D-glucose
Other name(s): dextran 1,2-α-glucosidase; dextran α-1,2 debranching enzymel 1,2-α-D-glucosyl-branched-dextran 2-glucohydrolase
Systematic name: (1→2)-α-D-glucosyl-branched-dextran 2-glucohydrolase
Comments: Does not hydrolyse disaccharides or oligosaccharides containing linear 1,2-α-glucosidic linkages.
References:
1.  Mitsuishi, Y., Kobayashi, M. and Matsuda, K. Dextran α-1,2-debranching enzyme from Flavobacterium sp. M-73: its production and purification. Agric. Biol. Chem. 43 (1979) 2283–2290.
2.  Mitsuishi, Y., Kobayashi, M. and Matsuda, K. Dextran α-(1→2)-debranching enzyme from Flavobacterium sp. M-73. Properties and mode of action. Carbohydr. Res. 83 (1980) 303–313. [PMID: 7407800]
[EC 3.2.1.115 created 1989]
 
 
EC 2.4.1.101     Relevance: 17.2%
Accepted name: α-1,3-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + Man5GlcNAc2-[protein] = UDP + Man5GlcNAc3-[protein]
Glossary: Man5GlcNAc2-[protein] = α-D-Man-(1→3)-[α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-N-Asn-[protein]
Man5GlcNAc3-[protein]= β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-N-Asn-[protein]
Other name(s): MGAT1 (gene name); N-acetylglucosaminyltransferase I; N-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase I; uridine diphosphoacetylglucosamine-α-1,3-mannosylglycoprotein β-1,2-N-acetylglucosaminyltransferase; UDP-N-acetylglucosaminyl:α-1,3-D-mannoside-β-1,2-N-acetylglucosaminyltransferase I; UDP-N-acetylglucosaminyl:α-3-D-mannoside β-1,2-N-acetylglucosaminyltransferase I; α-1,3-mannosyl-glycoprotein β-1,2-N-acetylglucosaminyltransferase; GnTI; GlcNAc-T I; UDP-N-acetyl-D-glucosamine:3-(α-D-mannosyl)-β-D-mannosyl-glycoprotein 2-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:α-D-mannosyl-(1→3)-β-D-mannosyl-glycoprotein 2-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: The enzyme, found in plants and animals, participates in the processing of N-glycans in the Golgi apparatus. Its action is required before the other N-acetylglucosaminyltransferases involved in the process (GlcNAcT-II through VI) can act. While the natural substrate (produced by EC 3.2.1.113, mannosyl-oligosaccharide 1,2-α-mannosidase) is described here, the minimal substrate recognized by the enzyme is α-D-Man-(1→3)-β-D-Man-R.
References:
1.  Harpaz, N. and Schachter, H. Control of glycoprotein synthesis. Bovine colostrum UDP-N-acetylglucosamine:α-D-mannoside β2-N-acetylglucosaminyltransferase I. Separation from UDP-N-acetylglucosamine:α-D-mannoside β2-N-acetylglucosaminyltransferase II, partial purification, and substrate specificity. J. Biol. Chem. 255 (1980) 4885–4893. [PMID: 6445358]
2.  Mendicino, J., Chandrasekaran, E.V., Anumula, K.R. and Davila, M. Isolation and properties of α-D-mannose:β-1,2-N-acetylglucosaminyltransferase from trachea mucosa. Biochemistry 20 (1981) 967–976. [PMID: 6452163]
3.  Oppenheimer, C.L. and Hill, R.L. Purification and characterization of a rabbit liver α1→3 mannoside β1→2 N-acetylglucosaminyltransferase. J. Biol. Chem. 256 (1981) 799–804. [PMID: 6450208]
4.  Oppenheimer, C.L., Eckhardt, A.E. and Hill, R.L. The nonidentity of porcine N-acetylglucosaminyltransferases I and II. J. Biol. Chem. 256 (1981) 11477–11482. [PMID: 6457827]
5.  Miyagi, T. and Tsuiki, S. Studies on UDP-N-acetylglucosamine : α-mannoside β-N-acetylglucosaminyltransferase of rat liver and hepatomas. Biochim. Biophys. Acta 661 (1981) 148–157. [PMID: 6170335]
6.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
7.  Vella, G.J., Paulsen, H. and Schachter, H. Control of glycoprotein synthesis. IX. A terminal Man alphal-3Man β1- sequence in the substrate is the minimum requirement for UDP-N-acetyl-D-glucosamine: α-D-mannoside (GlcNAc to Man α1-3) β2-N-acetylglucosaminyltransferase I. Can. J. Biochem. Cell Biol. 62 (1984) 409–417. [PMID: 6235906]
8.  Unligil, U.M., Zhou, S., Yuwaraj, S., Sarkar, M., Schachter, H. and Rini, J.M. X-ray crystal structure of rabbit N-acetylglucosaminyltransferase I: catalytic mechanism and a new protein superfamily. EMBO J. 19 (2000) 5269–5280. [PMID: 11032794]
[EC 2.4.1.101 created 1983, modified 2001 (EC 2.4.1.51 created 1972, part incorporated 1984), modified 2018]
 
 
EC 3.2.1.111     Relevance: 17.2%
Accepted name: 1,3-α-L-fucosidase
Reaction: Hydrolysis of (1→3)-linkages between α-L-fucose and N-acetylglucosamine residues in glycoproteins
Other name(s): almond emulsin fucosidase I
Systematic name: 3-α-L-fucosyl-N-acetylglucosaminyl-glycoprotein fucohydrolase
Comments: Not identical with EC 3.2.1.63 1,2-α-L-fucosidase.
References:
1.  Imber, M.J., Glasgow, L.R. and Pizzo, S.V. Purification of an almond emulsin fucosidase on Cibacron blue-sepharose and demonstration of its activity toward fucose-containing glycoproteins. J. Biol. Chem. 257 (1982) 8205–8210. [PMID: 7085666]
2.  Ogata-Arakawa, M., Muramatsu, T. and Kobata, A. α-L-Fucosidases from almond emulsin: characterization of the two enzymes with different specificities. Arch. Biochem. Biophys. 181 (1977) 353–358. [PMID: 18111]
3.  Yoshima, H., Takasaki, S., Ito-Mega, S. and Kobata, A. Purification of almond emulsin α-L-fucosidase I by affinity chromatography. Arch. Biochem. Biophys. 194 (1979) 394–398. [PMID: 443810]
[EC 3.2.1.111 created 1986]
 
 
EC 2.7.8.42     Relevance: 17.2%
Accepted name: Kdo2-lipid A phosphoethanolamine 7′′-transferase
Reaction: (1) diacylphosphatidylethanolamine + α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid A = diacylglycerol + 7-O-[2-aminoethoxy(hydroxy)phosphoryl]-α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid A
(2) diacylphosphatidylethanolamine + α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid IVA = diacylglycerol + 7-O-[2-aminoethoxy(hydroxy)phosphoryl]-α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid IVA
Glossary: lipid A = 2-deoxy-2-[(3R)-3-(tetradecanoyloxy)tetradecanamido]-3-O-[(3R)-3-(dodecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
lipid IVA = 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
Other name(s): eptB (gene name)
Systematic name: diacylphosphatidylethanolamine:α-D-Kdo-(2→4)-α-D-Kdo-(2→6)-lipid-A 7′′-phosphoethanolaminetransferase
Comments: The enzyme has been characterized from the bacterium Escherichia coli. It is activated by Ca2+ ions and is silenced by the sRNA MgrR.
References:
1.  Kanipes, M.I., Lin, S., Cotter, R.J. and Raetz, C.R. Ca2+-induced phosphoethanolamine transfer to the outer 3-deoxy-D-manno-octulosonic acid moiety of Escherichia coli lipopolysaccharide. A novel membrane enzyme dependent upon phosphatidylethanolamine. J. Biol. Chem. 276 (2001) 1156–1163. [PMID: 11042192]
2.  Reynolds, C.M., Kalb, S.R., Cotter, R.J. and Raetz, C.R. A phosphoethanolamine transferase specific for the outer 3-deoxy-D-manno-octulosonic acid residue of Escherichia coli lipopolysaccharide. Identification of the eptB gene and Ca2+ hypersensitivity of an eptB deletion mutant. J. Biol. Chem. 280 (2005) 21202–21211. [PMID: 15795227]
3.  Moon, K., Six, D.A., Lee, H.J., Raetz, C.R. and Gottesman, S. Complex transcriptional and post-transcriptional regulation of an enzyme for lipopolysaccharide modification. Mol. Microbiol. 89 (2013) 52–64. [PMID: 23659637]
[EC 2.7.8.42 created 2015]
 
 
EC 2.4.1.123     Relevance: 17.1%
Accepted name: inositol 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + myo-inositol = UDP + O-α-D-galactosyl-(1→3)-1D-myo-inositol
Glossary: O-α-D-galactosyl-(1→3)-1D-myo-inositol = galactinol
Other name(s): UDP-D-galactose:inositol galactosyltransferase; UDP-galactose:myo-inositol 1-α-D-galactosyltransferase; UDPgalactose:myo-inositol 1-α-D-galactosyltransferase; galactinol synthase; inositol 1-α-galactosyltransferase; uridine diphosphogalactose-inositol galactosyltransferase; GolS; UDP-galactose:myo-inositol 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:myo-inositol 3-α-D-galactosyltransferase
Comments: An enzyme from plants involved in the formation of raffinose and stachyose [cf. EC 2.4.1.67 (galactinol—raffinose galactosyltransferase) and EC 2.4.1.82 (galactinol—sucrose galactosyltransferase)].
References:
1.  Pharr, D.M., Sox, H.N., Locy, R.D. and Huber, S.C. Partial characterization of the galactinol forming enzyme from leaves of Cucumis sativus L. Plant Sci. Lett. 23 (1981) 25–33.
[EC 2.4.1.123 created 1984, modified 2003]
 
 
EC 2.3.1.273     Relevance: 17.1%
Accepted name: diglucosylglycerate octanoyltransferase
Reaction: octanoyl-CoA + 2-O-[α-D-glucopyranosyl-(1→6)-α-D-glucopyranosyl]-D-glycerate = CoA + 2-O-[6-O-octanoyl-α-D-glucopyranosyl-(1→6)-α-D-glucopyranosyl]-D-glycerate
Other name(s): octT (gene name); DGG octanoyltransferase
Systematic name: octanoyl-CoA:2-O-[α-D-glucopyranosyl-(1→6)-α-D-glucopyranosyl]-D-glycerate octanoyltransferase
Comments: The enzyme, characterized from mycobacteria, is involved in the biosynthesis of methylglucose lipopolysaccharide (MGLP). The enzyme can also act on 2-O-(α-D-glucopyranosyl)-D-glycerate, but with lower activity.
References:
1.  Maranha, A., Moynihan, P.J., Miranda, V., Correia Lourenco, E., Nunes-Costa, D., Fraga, J.S., Jose Barbosa Pereira, P., Macedo-Ribeiro, S., Ventura, M.R., Clarke, A.J. and Empadinhas, N. Octanoylation of early intermediates of mycobacterial methylglucose lipopolysaccharides. Sci. Rep. 5:13610 (2015). [PMID: 26324178]
[EC 2.3.1.273 created 2018]
 
 
EC 3.2.1.93     Relevance: 17%
Accepted name: α,α-phosphotrehalase
Reaction: α,α-trehalose 6-phosphate + H2O = D-glucose + D-glucose 6-phosphate
Other name(s): phosphotrehalase
Systematic name: α,α-trehalose-6-phosphate phosphoglucohydrolase
References:
1.  Bhumiratana, A., Anderson, R.L. and Costilow, R.N. Trehalose metabolism by Bacillus popilliae. J. Bacteriol. 119 (1974) 484–493. [PMID: 4369400]
[EC 3.2.1.93 created 1976]
 
 
EC 2.7.7.69     Relevance: 17%
Accepted name: GDP-L-galactose/GDP-D-glucose: hexose 1-phosphate guanylyltransferase
Reaction: (1) GDP-β-L-galactose + α-D-mannose 1-phosphate = β-L-galactose 1-phosphate + GDP-α-D-mannose
(2) GDP-α-D-glucose + α-D-mannose 1-phosphate = α-D-glucose 1-phosphate + GDP-α-D-mannose
Other name(s): VTC2; VTC5; GDP-L-galactose phosphorylase
Systematic name: GDP-β-L-galactose/GDP-α-D-glucose:hexose 1-phosphate guanylyltransferase
Comments: This plant enzyme catalyses the conversion of GDP-β-L-galactose and GDP-α-D-glucose to β-L-galactose 1-phosphate and α-D-glucose 1-phosphate, respectively. The enzyme can use inorganic phosphate as the co-substrate, but several hexose 1-phosphates, including α-D-mannose 1-phosphate, α-D-glucose 1-phosphate, and α-D-galactose 1-phosphate, are better guanylyl acceptors. The enzyme's activity on GDP-β-L-galactose is crucial for the biosynthesis of L-ascorbate.
References:
1.  Linster, C.L., Gomez, T.A., Christensen, K.C., Adler, L.N., Young, B.D., Brenner, C. and Clarke, S.G. Arabidopsis VTC2 encodes a GDP-L-galactose phosphorylase, the last unknown enzyme in the Smirnoff-Wheeler pathway to ascorbic acid in plants. J. Biol. Chem. 282 (2007) 18879–18885. [PMID: 17462988]
2.  Dowdle, J., Ishikawa, T., Gatzek, S., Rolinski, S. and Smirnoff, N. Two genes in Arabidopsis thaliana encoding GDP-L-galactose phosphorylase are required for ascorbate biosynthesis and seedling viability. Plant J. 52 (2007) 673–689. [PMID: 17877701]
3.  Wolucka, B.A. and Van Montagu, M. The VTC2 cycle and the de novo biosynthesis pathways for vitamin C in plants: an opinion. Phytochemistry 68 (2007) 2602–2613. [PMID: 17950389]
4.  Laing, W.A., Wright, M.A., Cooney, J. and Bulley, S.M. The missing step of the L-galactose pathway of ascorbate biosynthesis in plants, an L-galactose guanyltransferase, increases leaf ascorbate content. Proc. Natl. Acad. Sci. USA 104 (2007) 9534–9539. [PMID: 17485667]
5.  Linster, C.L., Adler, L.N., Webb, K., Christensen, K.C., Brenner, C. and Clarke, S.G. A second GDP-L-galactose phosphorylase in arabidopsis en route to vitamin C. Covalent intermediate and substrate requirements for the conserved reaction. J. Biol. Chem. 283 (2008) 18483–18492. [PMID: 18463094]
6.  Muller-Moule, P. An expression analysis of the ascorbate biosynthesis enzyme VTC2. Plant Mol. Biol. 68 (2008) 31–41. [PMID: 18516687]
[EC 2.7.7.69 created 2010, modified 2020]
 
 
EC 2.4.1.301     Relevance: 17%
Accepted name: 2′-deamino-2′-hydroxyneamine 1-α-D-kanosaminyltransferase
Reaction: (1) UDP-α-D-kanosamine + 2′-deamino-2′-hydroxyneamine = UDP + kanamycin A
(2) UDP-α-D-kanosamine + neamine = UDP + kanamycin B
(3) UDP-α-D-kanosamine + paromamine = UDP + kanamycin C
(4) UDP-α-D-kanosamine + 2′-deamino-2′-hydroxyparomamine = UDP + kanamycin X
Glossary: neamine = (1R,2R,3S,4R,6S)-4,6-diamino-2,3-dihydroxycyclohexyl 2,6-diamino-2,6-dideoxy-α-D-glucopyranoside
paromamine = (1R,2R,3S,4R,6S)-4,6-diamino-2,3-dihydroxycyclohexyl 2-amino-2-deoxy-α-D-glucopyranoside
UDP-α-D-kanosamine = uridine 5′-[3-(3-amino-3-deoxy-α-D-glucopyranosyl) diphosphate]
kanamycin A = (1S,2R,3R,4S,6R)-4,6-diamino-3-(6-amino-6-deoxy-α-D-glucopyranosyloxy)-2-hydroxycyclohexyl 3-amino-3-deoxy-α-D-glucopyranoside
kanamycin B = (1R,2S,3S,4R,6S)-4,6-diamino-3-(3-amino-3-deoxy-α-D-glucopyranosyloxy)-2-hydroxycyclohexyl 2,6-diamino-2,6-dideoxy-α-D-glucopyranoside
kanamycin C = (1R,2S,3S,4R,6S)-4,6-diamino-3-(3-amino-3-deoxy-α-D-glucopyranosyloxy)-2-hydroxycyclohexyl 2-amino-2-deoxy-α-D-glucopyranoside
kanamycin X = (1S,2R,3R,4S,6R)-4,6-diamino-3-(α-D-glucopyranosyloxy)-2-hydroxycyclohexyl 3-amino-3-deoxy-α-D-glucopyranoside
Other name(s): kanE (gene name); kanM2 (gene name)
Systematic name: UDP-α-D-kanosamine:2′-deamino-2′-hydroxyneamine 1-α-D-kanosaminyltransferase
Comments: Involved in the biosynthetic pathway of kanamycins. The enzyme characterized from the bacterium Streptomyces kanamyceticus can also accept UDP-α-D-glucose with lower efficiency [2].
References:
1.  Kudo, F., Sucipto, H. and Eguchi, T. Enzymatic activity of a glycosyltransferase KanM2 encoded in the kanamycin biosynthetic gene cluster. J. Antibiot. (Tokyo) 62 (2009) 707–710. [PMID: 19911031]
2.  Park, J.W., Park, S.R., Nepal, K.K., Han, A.R., Ban, Y.H., Yoo, Y.J., Kim, E.J., Kim, E.M., Kim, D., Sohng, J.K. and Yoon, Y.J. Discovery of parallel pathways of kanamycin biosynthesis allows antibiotic manipulation. Nat. Chem. Biol. 7 (2011) 843–852. [PMID: 21983602]
[EC 2.4.1.301 created 2013]
 
 
EC 2.4.1.348     Relevance: 17%
Accepted name: N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 3-α-mannosyltransferase
Reaction: GDP-α-D-mannose + N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = GDP + α-D-mannosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbdC
Systematic name: GDP-α-D-mannose:N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 3-α-mannosyltransferase (configuration-retaining)
Comments: The enzyme is involved in the biosynthesis of the linker region of the polymannose O-polysaccharide in the outer leaflet of the membrane of Escherichia coli serotypes O8, O9 and O9a.
References:
1.  Greenfield, L.K., Richards, M.R., Li, J., Wakarchuk, W.W., Lowary, T.L. and Whitfield, C. Biosynthesis of the polymannose lipopolysaccharide O-antigens from Escherichia coli serotypes O8 and O9a requires a unique combination of single- and multiple-active site mannosyltransferases. J. Biol. Chem. 287 (2012) 35078–35091. [PMID: 22875852]
[EC 2.4.1.348 created 2017]
 
 
EC 5.4.99.52     Relevance: 16.9%
Accepted name: α-seco-amyrin synthase
Reaction: (3S)-2,3-epoxy-2,3-dihydrosqualene = α-seco-amyrin
Glossary: α-seco-amyrin = 8,14-secoursa-7,13-diene-3β-ol
Systematic name: (3S)-2,3-epoxy-2,3-dihydrosqualene mutase (cyclizing, α-seco-amyrin-forming)
Comments: The enzyme from Arabidopsis thaliana is multifunctional and produces about equal amounts of α- and β-seco-amyrin. See EC 5.4.99.54, β-seco-amyrin synthase.
References:
1.  Shibuya, M., Xiang, T., Katsube, Y., Otsuka, M., Zhang, H. and Ebizuka, Y. Origin of structural diversity in natural triterpenes: direct synthesis of seco-triterpene skeletons by oxidosqualene cyclase. J. Am. Chem. Soc. 129 (2007) 1450–1455. [PMID: 17263431]
[EC 5.4.99.52 created 2011]
 
 
EC 3.2.1.70     Relevance: 16.9%
Accepted name: glucan 1,6-α-glucosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in (1→6)-α-D-glucans and derived oligosaccharides
Other name(s): exo-1,6-β-glucosidase; glucodextrinase; glucan α-1,6-D-glucohydrolase
Systematic name: glucan 6-α-D-glucohydrolase
Comments: Hydrolysis is accompanied by inversion at C-1, so that new reducing ends are released in the β-configuration. Dextrans and isomaltosaccharides are hydrolysed, as is isomaltose, but very slowly. The enzyme from some sources also possesses the activity of EC 3.2.1.59 (glucan endo-1,3-α-glucosidase).
References:
1.  Ohya, T., Sawai, T., Uemura, S. and Abe, K. Some catalytic properties of an exo-1,6-α-glucosidase (glucodextranase) from Arthrobacter globiformis I42. Agric. Biol. Chem. 42 (1978) 571–577.
2.  Sawai, T., Yamaki, T. and Ohya, T. Preparation and some properties of Arthrobacter globiformis exo-1,6-α-glucosidase. Agric. Biol. Chem. 40 (1976) 1293–1299.
3.  Walker, G.J. and Pulkownik, A. Degradation of dextrans by an α-1,6-glucan glucohydrolase from Streptococcus mitis. Carbohydr. Res. 29 (1973) 1–14. [PMID: 4356399]
[EC 3.2.1.70 created 1972, modified 2001]
 
 
EC 2.4.1.257     Relevance: 16.9%
Accepted name: GDP-Man:Man2GlcNAc2-PP-dolichol α-1,6-mannosyltransferase
Reaction: GDP-α-D-mannose + α-D-Man-(1→3)-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = GDP + α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol
Other name(s): GDP-Man:Man2GlcNAc2-PP-Dol α-1,6-mannosyltransferase; Alg2 mannosyltransferase (ambiguous); ALG2 (gene name, ambiguous); GDP-Man:Man1GlcNAc2-PP-dolichol mannosyltransferase (ambiguous); GDP-D-mannose:D-Man-α-(1→3)-D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol α-6-mannosyltransferase
Systematic name: GDP-α-D-mannose:α-D-Man-(1→3)-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 6-α-D-mannosyltransferase (configuration-retaining)
Comments: The biosynthesis of asparagine-linked glycoproteins utilizes a dolichyl diphosphate-linked glycosyl donor, which is assembled by the series of membrane-bound glycosyltransferases that comprise the dolichol pathway. Alg2 mannosyltransferase from Saccharomyces cerevisiae carries out an α1,3-mannosylation (cf. EC 2.4.1.132) of β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol, followed by an α1,6-mannosylation, to form the first branched pentasaccharide intermediate of the dolichol pathway [1,2].
References:
1.  Kampf, M., Absmanner, B., Schwarz, M. and Lehle, L. Biochemical characterization and membrane topology of Alg2 from Saccharomyces cerevisiae as a bifunctional α1,3- and 1,6-mannosyltransferase involved in lipid-linked oligosaccharide biosynthesis. J. Biol. Chem. 284 (2009) 11900–11912. [PMID: 19282279]
2.  O'Reilly, M.K., Zhang, G. and Imperiali, B. In vitro evidence for the dual function of Alg2 and Alg11: essential mannosyltransferases in N-linked glycoprotein biosynthesis. Biochemistry 45 (2006) 9593–9603. [PMID: 16878994]
[EC 2.4.1.257 created 2011, modified 2012]
 
 
EC 4.2.3.87     Relevance: 16.9%
Accepted name: α-guaiene synthase
Reaction: (2E,6E)-farnesyl diphosphate = α-guaiene + diphosphate
Other name(s): PatTps177 (gene name)
Systematic name: (2Z,6E)-farnesyl-diphosphate diphosphate-lyase (cyclizing, α-guaiene-forming)
Comments: Requires Mg2+. The enzyme from Pogostemon cablin gives 13% α-guaiene as well as 37% (-)-patchoulol (see EC 4.2.3.70), 13% δ-guaiene (see EC 4.2.3.93), and traces of at least ten other sesquiterpenoids [1]. In Aquilaria crassna three clones of the enzyme gave about 80% δ-guaiene and 20% α-guaiene, with traces of α-humulene. A fourth clone gave 54% δ-guaiene and 45% α-guaiene [2].
References:
1.  Deguerry, F., Pastore, L., Wu, S., Clark, A., Chappell, J. and Schalk, M. The diverse sesquiterpene profile of patchouli, Pogostemon cablin, is correlated with a limited number of sesquiterpene synthases. Arch. Biochem. Biophys. 454 (2006) 123–136. [PMID: 16970904]
2.  Kumeta, Y. and Ito, M. Characterization of δ-guaiene synthases from cultured cells of Aquilaria, responsible for the formation of the sesquiterpenes in agarwood. Plant Physiol. 154 (2010) 1998–2007. [PMID: 20959422]
[EC 4.2.3.87 created 2011]
 
 
EC 3.2.1.209     Relevance: 16.9%
Accepted name: endoplasmic reticulum Man9GlcNAc2 1,2-α-mannosidase
Reaction: Man9GlcNAc2-[protein] + H2O = Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) + D-mannopyranose
Glossary: Man9GlcNAc2-[protein] = {α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein]
Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) = {α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc}-N-Asn-[protein]
Other name(s): MAN1B1 (gene name); MNS1 (gene name); MNS3 (gene name)
Systematic name: Man9GlcNAc2-[protein]2-α-mannohydrolase (configuration-inverting)
Comments: The enzyme, located in the endoplasmic reticulum, primarily trims a single α-1,2-linked mannose residue from Man9GlcNAc2 to produce Man8GlcNAc2 isomer 8A1,2,3B1,3 (the names of the isomers listed here are based on a nomenclature system proposed by Prien et al [7]). The removal of the single mannosyl residue occurs in all eukaryotes as part of the processing of N-glycosylated proteins, and is absolutely essential for further elongation of the outer chain of properly-folded N-glycosylated proteins in yeast. In addition, the enzyme is involved in glycoprotein quality control at the ER quality control compartment (ERQC), helping to target misfolded glycoproteins for degradation. When present at very high concentrations in the ERQC, the enzyme can trim the carbohydrate chain further to Man(5-6)GlcNAc2.
References:
1.  Jelinek-Kelly, S. and Herscovics, A. Glycoprotein biosynthesis in Saccharomyces cerevisiae. Purification of the α-mannosidase which removes one specific mannose residue from Man9GlcNAc. J. Biol. Chem. 263 (1988) 14757–14763. [PMID: 3049586]
2.  Ziegler, F.D. and Trimble, R.B. Glycoprotein biosynthesis in yeast: purification and characterization of the endoplasmic reticulum Man9 processing α-mannosidase. Glycobiology 1 (1991) 605–614. [PMID: 1822240]
3.  Gonzalez, D.S., Karaveg, K., Vandersall-Nairn, A.S., Lal, A. and Moremen, K.W. Identification, expression, and characterization of a cDNA encoding human endoplasmic reticulum mannosidase I, the enzyme that catalyzes the first mannose trimming step in mammalian Asn-linked oligosaccharide biosynthesis. J. Biol. Chem. 274 (1999) 21375–21386. [PMID: 10409699]
4.  Herscovics, A., Romero, P.A. and Tremblay, L.O. The specificity of the yeast and human class I ER α 1,2-mannosidases involved in ER quality control is not as strict previously reported. Glycobiology 12 (2002) 14G–15G. [PMID: 12090241]
5.  Avezov, E., Frenkel, Z., Ehrlich, M., Herscovics, A. and Lederkremer, G.Z. Endoplasmic reticulum (ER) mannosidase I is compartmentalized and required for N-glycan trimming to Man5-6GlcNAc2 in glycoprotein ER-associated degradation. Mol. Biol. Cell 19 (2008) 216–225. [PMID: 18003979]
6.  Liebminger, E., Huttner, S., Vavra, U., Fischl, R., Schoberer, J., Grass, J., Blaukopf, C., Seifert, G.J., Altmann, F., Mach, L. and Strasser, R. Class I α-mannosidases are required for N-glycan processing and root development in Arabidopsis thaliana. Plant Cell 21 (2009) 3850–3867. [PMID: 20023195]
7.  Prien, J.M., Ashline, D.J., Lapadula, A.J., Zhang, H. and Reinhold, V.N. The high mannose glycans from bovine ribonuclease B isomer characterization by ion trap MS. J. Am. Soc. Mass Spectrom. 20 (2009) 539–556. [PMID: 19181540]
[EC 3.2.1.209 created 2019]
 
 
EC 3.2.1.51     Relevance: 16.9%
Accepted name: α-L-fucosidase
Reaction: an α-L-fucoside + H2O = L-fucose + an alcohol
Other name(s): α-fucosidase
Systematic name: α-L-fucoside fucohydrolase
References:
1.  Levvy, G.A. and McAllan, A. Mammalian fucosidases. 2. α-L-Fucosidase. Biochem. J. 80 (1961) 435–439. [PMID: 13761578]
2.  Reglero, A. and Cabezas, J.A. Glycosidases of molluscs. Purification and properties of α-L-fucosidase from Chamelea gallina L. Eur. J. Biochem. 66 (1976) 379–387. [PMID: 7458]
3.  Tanaka, K., Nakano, T., Noguchi, S. and Pigman, W. Purification of α-L-fucosidase of abalone livers. Arch. Biochem. Biophys. 126 (1968) 624–633. [PMID: 5672520]
[EC 3.2.1.51 created 1972]
 
 
EC 1.14.13.150      
Transferred entry: α-humulene 10-hydroxylase. Now EC 1.14.14.113, α-humulene 10-hydroxylase.
[EC 1.14.13.150 created 2012, deleted 2018]
 
 
EC 1.1.1.341     Relevance: 16.8%
Accepted name: CDP-abequose synthase
Reaction: CDP-α-D-abequose + NADP+ = CDP-4-dehydro-3,6-dideoxy-α-D-glucose + NADPH + H+
Glossary: CDP-α-D-abequose = CDP-3,6-dideoxy-α-D-xylo-hexose
Other name(s): rfbJ (gene name)
Systematic name: CDP-α-D-abequose:NADP+ 4-oxidoreductase
Comments: Isolated from Yersinia pseudotuberculosis [1,3] and Salmonella enterica [1,2].
References:
1.  Kessler, A.C., Brown, P.K., Romana, L.K. and Reeves, P.R. Molecular cloning and genetic characterization of the rfb region from Yersinia pseudotuberculosis serogroup IIA, which determines the formation of the 3,6-dideoxyhexose abequose. J. Gen. Microbiol. 137 (1991) 2689–2695. [PMID: 1724263]
2.  Wyk, P. and Reeves, P. Identification and sequence of the gene for abequose synthase, which confers antigenic specificity on group B salmonellae: homology with galactose epimerase. J. Bacteriol. 171 (1989) 5687–5693. [PMID: 2793832]
3.  Thorson, J.S., Lo, S.F., Ploux, O., He, X. and Liu, H.W. Studies of the biosynthesis of 3,6-dideoxyhexoses: molecular cloning and characterization of the asc (ascarylose) region from Yersinia pseudotuberculosis serogroup VA. J. Bacteriol. 176 (1994) 5483–5493. [PMID: 8071227]
[EC 1.1.1.341 created 2012]
 
 
EC 4.2.3.82     Relevance: 16.8%
Accepted name: α-santalene synthase
Reaction: (2E,6E)-farnesyl diphosphate = (+)-α-santalene + diphosphate
Glossary: (-)-exo-α-bergamotene = (-)-trans-α-bergamotene = (1S,5S,6R)-2,6-dimethyl-6-(4-methylpent-3-en-1-yl)bicyclo[3.1.1]hept-2-ene
Systematic name: (2E,6E)-farnesyl diphosphate lyase (cyclizing, (+)-α-santalene-forming)
Comments: The enzyme synthesizes a mixture of sesquiterpenoids from (2E,6E)-farnesyl diphosphate. As well as (+)-α-santalene, (-)-β-santalene and (-)-exo-α-bergamotene are formed with traces of (+)-epi-β-santalene. See EC 4.2.3.83 [(-)-β-santalene synthase], and EC 4.2.3.81 [(-)-exo-α-bergamotene synthase]. cf. EC 4.2.3.50 α-santalene synthase [(2Z,6Z)-farnesyl diphosphate cyclizing]
References:
1.  Jones, C.G., Moniodis, J., Zulak, K.G., Scaffidi, A., Plummer, J.A., Ghisalberti, E.L., Barbour, E.L. and Bohlmann, J. Sandalwood fragrance biosynthesis involves sesquiterpene synthases of both the terpene synthase (TPS)-a and TPS-b subfamilies, including santalene synthases. J. Biol. Chem. 286 (2011) 17445–17454. [PMID: 21454632]
[EC 4.2.3.82 created 2011]
 
 
EC 2.4.1.334     Relevance: 16.8%
Accepted name: 1,3-α-oligoglucan phosphorylase
Reaction: [(1→3)-α-D-glucosyl]n + phosphate = [(1→3)-α-D-glucosyl]n-1 + β-D-glucose 1-phosphate
Systematic name: 1,3-α-D-glucan:phosphate β-D-glucosyltransferase
Comments: The enzyme, isolated from the bacterium Clostridium phytofermentans, catalyses a reversible reaction. Substrates for the phosphorolytic reaction are α-1,3-linked oligoglucans with a polymerisation degree of 3 or more. Nigerose (i.e. 3-O-α-D-glucopyranosyl-D-glucopyranose) is not phosphorylyzed but can serve as substrate in the reverse direction (cf. EC 2.4.1.279, nigerose phosphorylase).
References:
1.  Nihira, T., Nishimoto, M., Nakai, H., Ohtsubo, K., and Kitaoka, M. Characterization of two phosphorylases for α-1,3-oligoglucans from Clostridium phytofermentans. J. Appl. Glycosci. 61 (2014) 59–66.
[EC 2.4.1.334 created 2014]
 
 
EC 3.2.1.189     Relevance: 16.7%
Accepted name: dioscin glycosidase (diosgenin-forming)
Reaction: 3-O-[α-L-Rha-(1→4)-[α-L-Rha-(1→2)]-β-D-Glc]diosgenin + 3 H2O = D-glucose + 2 L-rhamnose + diosgenin
Glossary: 3-O-[α-L-Rha-(1→4)-[α-L-Rha-(1→2)]-β-D-Glc]diosgenin = (3β,25R)-spirost-5-en-3-yl 6-deoxy-α-L-mannopyranosyl-(1→2)-[6-deoxy-α-L-mannopyranosyl-(1→4)]-β-D-glucopyranoside = dioscin
diosgenin = (3β,25R)-spirost-5-en-3-ol
Other name(s): dioscin glycosidase (aglycone-forming)
Systematic name: 3-O-[α-L-Rha-(1→4)-[α-L-Rha-(1→2)]-β-D-Glc]diosgenin hydrolase (diosgenin-forming)
Comments: The enzyme is involved in degradation of the steroid saponin dioscin by some fungi of the Absidia genus. The enzyme can also hydrolyse 3-O-[α-L-Ara-(1→4)-[α-L-Rha-(1→2)]-β-D-Glc]diosgenin into diosgenin and free sugars as the final products. cf. EC 3.2.1.190, dioscin glycosidase (3-O-β-D-Glc-diosgenin-forming).
References:
1.  Fu, Y., Yu, H., Tang, S.H., Hu, X., Wang, Y., Liu, B., Yu, C. and Jin, F. New dioscin-glycosidase hydrolyzing multi-glycosides of dioscin from Absidia strain. J. Microbiol. Biotechnol. 20 (2010) 1011–1017. [PMID: 20622501]
[EC 3.2.1.189 created 2013]
 
 
EC 3.2.1.114     Relevance: 16.7%
Accepted name: mannosyl-oligosaccharide 1,3-1,6-α-mannosidase
Reaction: Man5GlcNAc3-[protein] + 2 H2O = Man3GlcNAc3-[protein] + 2 α-D-mannopyranose
Glossary: Man5GlcNAc3-[protein] = [β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-{α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)}-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc]-N-Asn-[protein]
Man3GlcNAc3-[protein] = {β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-N-Asn-[protein]
Other name(s): MAN2A1 (gene name); MAN2A2 (gene name); mannosidase II; exo-1,3-1,6-α-mannosidase; α-D-mannosidase II; α-mannosidase II; α1-3,6-mannosidase; GlcNAc transferase I-dependent α1,3[α1,6]mannosidase; Golgi α-mannosidase II; ManII; 1,3(1,6)-α-D-mannosidase; 1,3-(1,6-)mannosyl-oligosaccharide α-D-mannohydrolase; (1→3)-(1→6)-mannosyl-oligosaccharide α-D-mannohydrolase
Systematic name: (1→3)-(1→6)-mannosyl-oligosaccharide α-D-mannohydrolase (configuration-retaining)
Comments: The enzyme, found in plants and animals, participates in the processing of N-glycans in the Golgi apparatus. It removes two mannosyl residues, one linked by α1,3 linkage, and the other linked by α1,6 linkage, both of which are removed by the same catalytic site. The enzyme is sensitive to swainsonine.
References:
1.  Tulsiani, D.R.P., Opheim, D.J. and Touster, O. Purification and characterization of α-D-mannosidase from rat liver golgi membranes. J. Biol. Chem. 252 (1977) 3227–3233. [PMID: 863880]
2.  Tabas, I. and Kornfeld, S. The synthesis of complex-type oligosaccharides. III. Identification of an α-D-mannosidase activity involved in a late stage of processing of complex-type oligosaccharides. J. Biol. Chem. 253 (1978) 7779–7786. [PMID: 212436]
3.  Harpaz, N. and Schachter, H. Control of glycoprotein synthesis. Processing of asparagine-linked oligosaccharides by one or more rat liver Golgi α-D-mannosidases dependent on the prior action of UDP-N-acetylglucosamine: α-D-mannoside β2-N-acetylglucosaminyltransferase I. J. Biol. Chem. 255 (1980) 4894–4902. [PMID: 6445359]
4.  Tulsiani, D.R.P., Hubbard, S.C., Robbins, P.W. and Touster, O. α-D-Mannosidases of rat liver Golgi membranes. Mannosidase II is the GlcNAcMAN5-cleaving enzyme in glycoprotein biosynthesis and mannosidases IA and IB are the enzymes converting Man9 precursors to Man5 intermediates. J. Biol. Chem. 257 (1982) 3660–3668. [PMID: 7061502]
5.  Moremen, K.W. and Robbins, P.W. Isolation, characterization, and expression of cDNAs encoding murine α-mannosidase II, a Golgi enzyme that controls conversion of high mannose to complex N-glycans. J. Cell Biol. 115 (1991) 1521–1534. [PMID: 1757461]
6.  Misago, M., Liao, Y.F., Kudo, S., Eto, S., Mattei, M.G., Moremen, K.W. and Fukuda, M.N. Molecular cloning and expression of cDNAs encoding human α-mannosidase II and a previously unrecognized α-mannosidase IIx isozyme. Proc. Natl. Acad. Sci. USA 92 (1995) 11766–11770. [PMID: 8524845]
7.  van den Elsen, J.M., Kuntz, D.A. and Rose, D.R. Structure of Golgi α-mannosidase II: a target for inhibition of growth and metastasis of cancer cells. EMBO J. 20 (2001) 3008–3017. [PMID: 11406577]
8.  Athanasopoulos, V.I., Niranjan, K. and Rastall, R.A. The production, purification and characterisation of two novel α-D-mannosidases from Aspergillus phoenicis. Carbohydr. Res. 340 (2005) 609–617. [PMID: 15721331]
9.  Shah, N., Kuntz, D.A. and Rose, D.R. Golgi α-mannosidase II cleaves two sugars sequentially in the same catalytic site. Proc. Natl. Acad. Sci. USA 105 (2008) 9570–9575. [PMID: 18599462]
10.  Rose, D.R. Structure, mechanism and inhibition of Golgi α-mannosidase II. Curr. Opin. Struct. Biol. 22 (2012) 558–562. [PMID: 22819743]
[EC 3.2.1.114 created 1986, modified 2018]
 
 
EC 1.1.3.48     Relevance: 16.7%
Accepted name: 3-deoxy-α-D-manno-octulosonate 8-oxidase
Reaction: 3-deoxy-α-D-manno-octulopyranosonate + O2 = 3,8-dideoxy-8-oxo-α-D-manno-octulosonate + H2O2
Glossary: 3-deoxy-α-D-manno-octulosonate = Kdo
3,8-dideoxy-8-oxo-α-D-manno-octulosonate = (2R,4R,5R,6S)-2,4,5-trihydroxy-6-[(1S)-1-hydroxy-2-oxoethyl]oxane-2-carboxylate
Other name(s): kdnB (gene name)
Systematic name: 3-deoxy-α-D-manno-octulopyranosonate:oxygen 8-oxidoreductase
Comments: The enzyme, characterized from the bacterium Shewanella oneidensis, is involved in the formation of 8-amino-3,8-dideoxy-α-D-manno-octulosonate, an aminated form of Kdo found in lipopolysaccharides of members of the Shewanella genus. cf. EC 2.6.1.109, 8-amino-3,8-dideoxy-α-D-manno-octulosonate transaminase.
References:
1.  Gattis, S.G., Chung, H.S., Trent, M.S. and Raetz, C.R. The origin of 8-amino-3,8-dideoxy-D-manno-octulosonic acid (Kdo8N) in the lipopolysaccharide of Shewanella oneidensis. J. Biol. Chem. 288 (2013) 9216–9225. [PMID: 23413030]
[EC 1.1.3.48 created 2015]
 
 
EC 6.3.2.25     Relevance: 16.7%
Accepted name: tubulin—tyrosine ligase
Reaction: ATP + detyrosinated α-tubulin + L-tyrosine = α-tubulin + ADP + phosphate
Systematic name: α-tubulin:L-tyrosine ligase (ADP-forming)
Comments: L-Tyrosine is linked via a peptide bond to the C-terminus of de-tyrosinated α-tubulin (des-Tyrω-α-tubulin). The enzyme is highly specific for α-tubulin and moderately specific for ATP and L-tyrosine. L-Phenylalanine and 3,4-dihydroxy-L-phenylalanine are transferred but with higher Km values.
References:
1.  Wehland, J., Schröder, H.C., Weber, K. Isolation and purification of tubulin-tyrosine ligase. Methods Enzymol. 134 (1986) 170–179. [PMID: 3821560]
2.  Rudiger, M., Wehland, J., Weber, K. The carboxy-terminal peptide of detyrosinated α tubulin provides a minimal system to study the substrate specificity of tubulin-tyrosine ligase. Eur. J. Biochem. 220 (1994) 309–320. [PMID: 7510228]
[EC 6.3.2.25 created 1999]
 
 
EC 2.4.1.5     Relevance: 16.6%
Accepted name: dextransucrase
Reaction: sucrose + [(1→6)-α-D-glucosyl]n = D-fructose + [(1→6)-α-D-glucosyl]n+1
Other name(s): sucrose 6-glucosyltransferase; SGE; CEP; sucrose-1,6-α-glucan glucosyltransferase; sucrose:1,6-α-D-glucan 6-α-D-glucosyltransferase
Systematic name: sucrose:(1→6)-α-D-glucan 6-α-D-glucosyltransferase
Comments: The glucansucrases transfer a D-glucosyl residue from sucrose to a glucan chain. They are classified based on the linkage by which they attach the transferred residue. In some cases, in which the enzyme forms more than one linkage type, classification relies on the relative proportion of the linkages that are generated. This enzyme extends the glucan chain by an α(1→6) linkage.
References:
1.  Bailey, R.W. Transglucosidase activity of rumen strains of Streptococcus bovis. 2. Isolation and properties of dextransucrase. Biochem. J. 72 (1959) 42–49. [PMID: 13651133]
2.  Bailey, R.W., Barker, S.A., Bourne, E.J. and Stacey, M. Immunopolysaccharides. Part VI. The isolation and properties of the dextransucrase of Betacoccus arabinosaceous. J. Chem. Soc. (Lond.) (1957) 3530–3536.
3.  Hehre, E.J. Enzymic synthesis of polysaccharides: a biological type of polymerization. Adv. Enzymol. Relat. Subj. Biochem. 11 (1951) 297–337. [PMID: 24540594]
[EC 2.4.1.5 created 1961]
 
 
EC 3.2.1.95     Relevance: 16.6%
Accepted name: dextran 1,6-α-isomaltotriosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in dextrans, to remove successive isomaltotriose units from the non-reducing ends of the chains
Other name(s): exo-isomaltotriohydrolase; 1,6-α-D-glucan isomaltotriohydrolase
Systematic name: 6-α-D-glucan isomaltotriohydrolase
References:
1.  Sugiura, M., Ito, A. and Yamaguchi, T. Studies on dextranase. II. New exo-dextranase from Brevibacterium fuscum var. Dextranlyticum. Biochim. Biophys. Acta 350 (1974) 61–70. [PMID: 4210084]
[EC 3.2.1.95 created 1978]
 
 
EC 2.1.2.14     Relevance: 16.6%
Accepted name: GDP-perosamine N-formyltransferase
Reaction: 10-formyltetrahydrofolate + GDP-α-D-perosamine = tetrahydrofolate + GDP-N-formyl-α-D-perosamine
Glossary: GDP-α-D-perosamine = GDP-4-amino-4,6-dideoxy-α-D-mannose
Other name(s): wbkC (gene name)
Systematic name: 10-formyltetrahydrofolate:GDP-α-D-perosamine N-formyltransferase
Comments: The enzyme, characterized from the bacterium Brucella melitensis, synthesizes a building block of the O antigen produced by Brucella species.
References:
1.  Godfroid, F., Cloeckaert, A., Taminiau, B., Danese, I., Tibor, A., de Bolle, X., Mertens, P. and Letesson, J.J. Genetic organisation of the lipopolysaccharide O-antigen biosynthesis region of Brucella melitensis 16M (wbk). Res. Microbiol. 151 (2000) 655–668. [PMID: 11081580]
2.  Riegert, A.S., Chantigian, D.P., Thoden, J.B., Tipton, P.A. and Holden, H.M. Biochemical characterization of WbkC, an N-formyltransferase from Brucella melitensis. Biochemistry 56 (2017) 3657–3668. [PMID: 28636341]
[EC 2.1.2.14 created 2021]
 
 
EC 2.4.3.10     Relevance: 16.6%
Accepted name: N-acetylglucosaminide α-(2,6)-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-[N-acetyl-α-neuraminyl-(2→6)]-N-acetyl-β-D-glucosaminyl-R
Other name(s): α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylglucosaminide 6-α-sialyltransferase; N-acetylglucosaminide (α 2→6)-sialyltransferase; ST6GlcNAc
Systematic name: CMP-N-acetylneuraminate:N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminide N-acetyl-β-D-glucosamine-6-α-N-acetylneuraminyltransferase (configuration-inverting)
Comments: Attaches N-acetylneuraminic acid in α-2,6-linkage to N-acetyl-β-D-glucosamine. The enzyme from rat liver also acts on β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl residues, but more slowly.
References:
1.  Paulson, J.C., Weinstein, J. and de Souza-e-Silva, U. Biosynthesis of a disialylated sequence in N-linked oligosaccharides: identification of an N-acetylglucosaminide (α 2→6)-sialyltransferase in Golgi apparatus from rat liver. Eur. J. Biochem. 140 (1984) 523–530. [PMID: 6547092]
[EC 2.4.3.10 created 2020 as EC 2.4.99.22, transferred 2022 to EC 2.4.3.10]
 
 
EC 2.4.99.22      
Transferred entry: N-acetylglucosaminide α-(2,6)-sialyltransferase. Now EC 2.4.3.10, N-acetylglucosaminide α-(2,6)-sialyltransferase
[EC 2.4.99.22 created 2020, deleted 2022]
 
 
EC 2.6.1.102     Relevance: 16.6%
Accepted name: GDP-perosamine synthase
Reaction: GDP-α-D-perosamine + 2-oxoglutarate = GDP-4-dehydro-α-D-rhamnose + L-glutamate
Glossary: GDP-α-D-perosamine = GDP-4-amino-4,6-dideoxy-α-D-mannose
GDP-4-dehydro-α-D-rhamnose = GDP-4-dehydro-6-deoxy-α-D-mannose
Other name(s): RfbE; GDP-4-keto-6-deoxy-D-mannose-4-aminotransferase; GDP-perosamine synthetase; PerA; GDP-4-amino-4,6-dideoxy-α-D-mannose:2-oxoglutarate aminotransferase
Systematic name: GDP-α-D-perosamine:2-oxoglutarate aminotransferase
Comments: A pyridoxal 5′-phosphate enzyme. D-Perosamine is one of several dideoxy sugars found in the O-specific polysaccharide of the lipopolysaccharide component of the outer membrane of Gram-negative bacteria. The enzyme catalyses the final step in GDP-α-D-perosamine synthesis.
References:
1.  Albermann, C. and Piepersberg, W. Expression and identification of the RfbE protein from Vibrio cholerae O1 and its use for the enzymatic synthesis of GDP-D-perosamine. Glycobiology 11 (2001) 655–661. [PMID: 11479276]
2.  Zhao, G., Liu, J., Liu, X., Chen, M., Zhang, H. and Wang, P.G. Cloning and characterization of GDP-perosamine synthetase (Per) from Escherichia coli O157:H7 and synthesis of GDP-perosamine in vitro. Biochem. Biophys. Res. Commun. 363 (2007) 525–530. [PMID: 17888872]
3.  Albermann, C. and Beuttler, H. Identification of the GDP-N-acetyl-d-perosamine producing enzymes from Escherichia coli O157:H7. FEBS Lett. 582 (2008) 479–484. [PMID: 18201574]
4.  Cook, P.D., Carney, A.E. and Holden, H.M. Accommodation of GDP-linked sugars in the active site of GDP-perosamine synthase. Biochemistry 47 (2008) 10685–10693. [PMID: 18795799]
[EC 2.6.1.102 created 2013]
 
 
EC 2.4.1.287     Relevance: 16.6%
Accepted name: rhamnopyranosyl-N-acetylglucosaminyl-diphospho-decaprenol β-1,4/1,5-galactofuranosyltransferase
Reaction: 2 UDP-α-D-galactofuranose + α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans,octacis-decaprenol = 2 UDP + β-D-galactofuranosyl-(1→5)-β-D-galactofuranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans,octacis-decaprenol (overall reaction)
(1a) UDP-α-D-galactofuranose + α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans-octacis-decaprenol = UDP + β-D-galactofuranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans-octacis-decaprenol
(1b) UDP-α-D-galactofuranose + β-D-galactofuranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans-octacis-decaprenol = UDP + β-D-galactofuranosyl-(1→5)-β-D-galactofuranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans-octacis-decaprenol
Other name(s): arabinogalactan galactofuranosyl transferase 1; GlfT1
Systematic name: UDP-α-D-galactofuranose:α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans,octacis-decaprenol 4-β/4-β-galactofuranosyltransferase (configuration-inverting)
Comments: Isolated from the bacteria Mycobacterium tuberculosis and M. smegmatis, the enzyme has dual β-(1→4) and β-(1→5) transferase action. Involved in the formation of the cell wall in mycobacteria.
References:
1.  Mikusová, K., Belánová, M., Korduláková, J., Honda, K., McNeil, M.R., Mahapatra, S., Crick, D.C. and Brennan, P.J. Identification of a novel galactosyl transferase involved in biosynthesis of the mycobacterial cell wall. J. Bacteriol. 188 (2006) 6592–6598. [PMID: 16952951]
2.  Belánová, M., Dianisková, P., Brennan, P.J., Completo, G.C., Rose, N.L., Lowary, T.L. and Mikusová, K. Galactosyl transferases in mycobacterial cell wall synthesis. J. Bacteriol. 190 (2008) 1141–1145. [PMID: 18055597]
[EC 2.4.1.287 created 2012, modified 2017]
 
 
EC 2.4.1.96     Relevance: 16.6%
Accepted name: sn-glycerol-3-phosphate 1-galactosyltransferase
Reaction: UDP-α-D-galactose + sn-glycerol 3-phosphate = UDP + 1-O-α-D-galactosyl-sn-glycerol 3-phosphate
Other name(s): isofloridoside-phosphate synthase; UDP-Gal:sn-glycero-3-phosphoric acid 1-α-galactosyl-transferase; UDPgalactose:sn-glycerol-3-phosphate α-D-galactosyltransferase; uridine diphosphogalactose-glycerol phosphate galactosyltransferase; glycerol 3-phosphate 1α-galactosyltransferase; UDP-galactose:sn-glycerol-3-phosphate 1-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:sn-glycerol-3-phosphate 1-α-D-galactosyltransferase
Comments: The product is hydrolysed by a phosphatase to isofloridoside, which is involved in osmoregulation (cf. EC 2.4.1.137 sn-glycerol-3-phosphate 2-α-galactosyltransferase).
References:
1.  Kauss, H. and Quader, H. In vitro activation of a galactosyl transferase involved in the osmotic regulation of Ochromonas. Plant Physiol. 58 (1976) 295–298. [PMID: 16659666]
2.  Kauss, H. and Schubert, B. `First demonstration of UDP-gal:sn-glycero-3-phosphoric acid 1α-galactosyl-transferase and its possible role in osmoregulation. FEBS Lett. 19 (1971) 131–135. [PMID: 11946194]
[EC 2.4.1.96 created 1978]
 
 
EC 2.4.1.293     Relevance: 16.6%
Accepted name: GalNAc5-diNAcBac-PP-undecaprenol β-1,3-glucosyltransferase
Reaction: UDP-α-D-glucose + [GalNAc-α-(1→4)]4-GalNAc-α-(1→3)-diNAcBac-diphospho-tritrans,heptacis-undecaprenol = UDP + [GalNAc-α-(1→4)]2-[Glc-β-(1→3)]-[GalNAc-α-(1→4)]2-GalNAc-α-(1→3)-diNAcBac-diphospho-tritrans,heptacis-undecaprenol
Glossary: diNAcBac = N,N′-diacetyl-D-bacillosamine = 2,4-diacetamido-2,4,6-trideoxy-D-glucopyranose
Other name(s): PglI
Systematic name: UDP-α-D-glucose:[GalNAc-α-(1→4)]4-GalNAc-α-(1→3)-diNAcBac-diphospho-tritrans,heptacis-undecaprenol 3-β-D-glucosyltransferase
Comments: Isolated from the bacterium Campylobacter jejuni. Part of a bacterial N-linked glycosylation pathway.
References:
1.  Glover, K.J., Weerapana, E. and Imperiali, B. In vitro assembly of the undecaprenylpyrophosphate-linked heptasaccharide for prokaryotic N-linked glycosylation. Proc. Natl. Acad. Sci. USA 102 (2005) 14255–14259. [PMID: 16186480]
2.  Kelly, J., Jarrell, H., Millar, L., Tessier, L., Fiori, L.M., Lau, P.C., Allan, B. and Szymanski, C.M. Biosynthesis of the N-linked glycan in Campylobacter jejuni and addition onto protein through block transfer. J. Bacteriol. 188 (2006) 2427–2434. [PMID: 16547029]
[EC 2.4.1.293 created 2012]
 
 
EC 1.14.13.105     Relevance: 16.6%
Accepted name: monocyclic monoterpene ketone monooxygenase
Reaction: (1) (–)-menthone + NADPH + H+ + O2 = (4R,7S)-7-isopropyl-4-methyloxepan-2-one + NADP+ + H2O
(2) dihydrocarvone + NADPH + H+ + O2 = 4-isopropenyl-7-methyloxepan-2-one + NADP+ + H2O
(3) (iso)-dihydrocarvone + NADPH + H+ + O2 = 6-isopropenyl-3-methyloxepan-2-one + NADP+ + H2O
(4a) 1-hydroxymenth-8-en-2-one + NADPH + H+ + O2 = 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one + NADP+ + H2O
(4b) 7-hydroxy-4-isopropenyl-7-methyloxepan-2-one = 3-isopropenyl-6-oxoheptanoate (spontaneous)
Other name(s): 1-hydroxy-2-oxolimonene 1,2-monooxygenase; dihydrocarvone 1,2-monooxygenase; MMKMO
Systematic name: (–)-menthone,NADPH:oxygen oxidoreductase
Comments: A flavoprotein (FAD). This Baeyer-Villiger monooxygenase enzyme from the Gram-positive bacterium Rhodococcus erythropolis DCL14 has wide substrate specificity, catalysing the lactonization of a large number of monocyclic monoterpene ketones and substituted cyclohexanones [2]. Both (1R,4S)- and (1S,4R)-1-hydroxymenth-8-en-2-one are metabolized, with the lactone product spontaneously rearranging to form 3-isopropenyl-6-oxoheptanoate [1].
References:
1.  van der Werf, M.J., Swarts, H.J. and de Bont, J.A. Rhodococcus erythropolis DCL14 contains a novel degradation pathway for limonene. Appl. Environ. Microbiol. 65 (1999) 2092–2102. [PMID: 10224006]
2.  Van Der Werf, M.J. Purification and characterization of a Baeyer-Villiger mono-oxygenase from Rhodococcus erythropolis DCL14 involved in three different monocyclic monoterpene degradation pathways. Biochem. J. 347 (2000) 693–701. [PMID: 10769172]
3.  van der Werf, M.J. and Boot, A.M. Metabolism of carveol and dihydrocarveol in Rhodococcus erythropolis DCL14. Microbiology 146 (2000) 1129–1141. [PMID: 10832640]
[EC 1.14.13.105 created 2008]
 
 
EC 2.4.1.359     Relevance: 16.6%
Accepted name: glucosylglycerol phosphorylase (configuration-retaining)
Reaction: 2-O-α-D-glucopyranosyl-glycerol + phosphate = α-D-glucose 1-phosphate + glycerol
Other name(s): 2-O-α-D-glucosylglycerol phosphorylase (retaining)
Systematic name: 2-O-α-D-glucopyranosyl-glycerol:phosphate α-D-glucosyltransferase (configuration-retaining)
Comments: The enzyme, characterized from the halotolerant bacterium Marinobacter adhaerens, is likely responsible for degradation of the compatible solute 2-O-α-D-glucopyranosyl-glycerol when the environmental salt concentration decreases. cf. EC 2.4.1.332, 1,2-α-glucosylglycerol phosphorylase.
References:
1.  Franceus, J., Decuyper, L., D'hooghe, M. and Desmet, T. Exploring the sequence diversity in glycoside hydrolase family 13_18 reveals a novel glucosylglycerol phosphorylase. Appl. Microbiol. Biotechnol. (2018) . [PMID: 29470619]
[EC 2.4.1.359 created 2018]
 
 
EC 2.4.1.4     Relevance: 16.6%
Accepted name: amylosucrase
Reaction: sucrose + [(1→4)-α-D-glucosyl]n = D-fructose + [(1→4)-α-D-glucosyl]n+1
Other name(s): sucrose—glucan glucosyltransferase; sucrose-1,4-α-glucan glucosyltransferase; sucrose:1,4-α-D-glucan 4-α-D-glucosyltransferase
Systematic name: sucrose:(1→4)-α-D-glucan 4-α-D-glucosyltransferase
Comments: The glucansucrases transfer a D-glucosyl residue from sucrose to a glucan chain. They are classified based on the linkage by which they attach the transferred residue. In some cases, in which the enzyme forms more than one linkage type, classification relies on the relative proportion of the linkages that are generated. This enzyme extends the glucan chain by an α(1→4) linkage.
References:
1.  Feingold, D.S., Avigad, G. and Hestrin, S. Enzymic synthesis and reactions of a sucrose isomer α-D-galactopyranosyl-β-D-fructofuranoside. J. Biol. Chem. 224 (1957) 295–307. [PMID: 13398406]
2.  Hehre, E.J. Enzymic synthesis of polysaccharides: a biological type of polymerization. Adv. Enzymol. Relat. Subj. Biochem. 11 (1951) 297–337. [PMID: 24540594]
3.  Hehre, E.J., Hamilton, D.M. and Carlson, A.S. Synthesis of a polysaccharide of the starch-glycogen class from sucrose by a cell-free, bacterial enzyme system (amylosucrase). J. Biol. Chem. 177 (1949) 267–279. [PMID: 18107430]
[EC 2.4.1.4 created 1961]
 
 
EC 3.2.1.77     Relevance: 16.6%
Accepted name: mannan 1,2-(1,3)-α-mannosidase
Reaction: Hydrolysis of (1→2)- and (1→3)-linkages in yeast mannan, releasing mannose
Other name(s): exo-1,2-1,3-α-mannosidase; 1,2-1,3-α-D-mannan mannohydrolase
Systematic name: (1→2)-(1→3)-α-D-mannan mannohydrolase
Comments: A 1,6-α-D-mannan backbone remains after action on yeast mannan. This is further attacked, but slowly.
References:
1.  Jones, G.H. and Ballou, C.E. Studies on the structure of yeast mannan. I. Purification and some properties of an α-mannosidase from an Arthrobacter species. J. Biol. Chem. 244 (1969) 1043–1051. [PMID: 5769177]
2.  Jones, G.H. and Ballou, C.E. Studies on the structure of yeast mannan. II. Mode of action of the Arthrobacter α-mannosidase on yeast mannan. J. Biol. Chem. 244 (1969) 1052–1059. [PMID: 5814027]
[EC 3.2.1.77 created 1972]
 
 
EC 1.1.1.281     Relevance: 16.5%
Accepted name: GDP-4-dehydro-6-deoxy-D-mannose reductase
Reaction: GDP-α-D-rhamnose + NAD(P)+ = GDP-4-dehydro-α-D-rhamnose + NAD(P)H + H+
Glossary: GDP-α-D-rhamnose = GDP-6-deoxy-α-D-mannose
GDP-4-dehydro-α-D-rhamnose = GDP-4-dehydro-6-deoxy-α-D-mannose
Other name(s): GDP-4-keto-6-deoxy-D-mannose reductase [ambiguous]; GDP-6-deoxy-D-lyxo-4-hexulose reductase; Rmd; GDP-6-deoxy-D-mannose:NAD(P)+ 4-oxidoreductase (D-rhamnose-forming); GDP-6-deoxy-α-D-mannose:NAD(P)+ 4-oxidoreductase (D-rhamnose-forming)
Systematic name: GDP-α-D-rhamnose:NAD(P)+ 4-oxidoreductase
Comments: This enzyme differs from EC 1.1.1.187, GDP-4-dehydro-D-rhamnose reductase, in that the only product formed is GDP-α-D-rhamnose. D-Rhamnose is a constituent of lipopolysaccharides of Gram-negative plant and human pathogenic bacteria.
References:
1.  Kneidinger, B., Graninger, M., Adam, G., Puchberger, M., Kosma, P., Zayni, S. and Messner, P. Identification of two GDP-6-deoxy-D-lyxo-4-hexulose reductases synthesizing GDP-D-rhamnose in Aneurinibacillus thermoaerophilus L420-91T. J. Biol. Chem. 276 (2001) 5577–5583. [PMID: 11096116]
2.  Mäki, M., Järvinen, N., Räbinä, J., Roos, C., Maaheimo, H., Mattila, P. and Renkonen, R. Functional expression of Pseudomonas aeruginosa GDP-4-keto-6-deoxy-D-mannose reductase which synthesizes GDP-rhamnose. Eur. J. Biochem. 269 (2002) 593–601. [PMID: 11856318]
[EC 1.1.1.281 created 2004]
 
 
EC 3.6.3.48      
Transferred entry: α-factor-transporting ATPase. Now EC 7.4.2.7 as α-factor-pheromone transporting ATPase
[EC 3.6.3.48 created 2000, deleted 2018]
 
 
EC 2.4.1.26     Relevance: 16.5%
Accepted name: DNA α-glucosyltransferase
Reaction: Transfers an α-D-glucosyl residue from UDP-glucose to an hydroxymethylcytosine residue in DNA
Other name(s): uridine diphosphoglucose-deoxyribonucleate α-glucosyltransferase; UDP-glucose-DNA α-glucosyltransferase; uridine diphosphoglucose-deoxyribonucleate α-glucosyltransferase; T2-HMC-α-glucosyl transferase; T4-HMC-α-glucosyl transferase; T6-HMC-α-glucosyl transferase
Systematic name: UDP-glucose:DNA α-D-glucosyltransferase
References:
1.  Kornberg, S.R., Zimmerman, S.B. and Kornberg, A. Glucosylation of deoxyribonucleic acid by enzymes from bacteriophage-infected Escherichia coli. J. Biol. Chem. 236 (1961) 1487–1493. [PMID: 13753193]
[EC 2.4.1.26 created 1965]
 
 
EC 2.3.1.227     Relevance: 16.5%
Accepted name: GDP-perosamine N-acetyltransferase
Reaction: acetyl-CoA + GDP-4-amino-4,6-dideoxy-α-D-mannose = CoA + GDP-4-acetamido-4,6-dideoxy-α-D-mannose
Glossary: GDP-4-amino-4,6-dideoxy-α-D-mannose = GDP-α-D-perosamine
GDP-4-acetamido-4,6-dideoxy-α-D-mannose = GDP-N-acetyl-α-D-perosamine
Other name(s): perB (gene name); GDP-α-D-perosamine N-acetyltransferase
Systematic name: acetyl-CoA:GDP-4-amino-4,6-dideoxy-α-D-mannose N-acetyltransferase
Comments: D-Perosamine is one of several dideoxy sugars found in the O-antigen component of the outer membrane lipopolysaccharides of Gram-negative bacteria.
References:
1.  Albermann, C. and Beuttler, H. Identification of the GDP-N-acetyl-d-perosamine producing enzymes from Escherichia coli O157:H7. FEBS Lett. 582 (2008) 479–484. [PMID: 18201574]
[EC 2.3.1.227 created 2013]
 
 
EC 2.7.1.168     Relevance: 16.5%
Accepted name: D-glycero-α-D-manno-heptose-7-phosphate kinase
Reaction: D-glycero-α-D-manno-heptose 7-phosphate + ATP = D-glycero-α-D-manno-heptose 1,7-bisphosphate + ADP
Other name(s): D-α-D-heptose-7-phosphate kinase; hdda (gene name)
Systematic name: ATP:D-glycero-α-D-manno-heptose 7-phosphate 1-phosphotransferase
Comments: The enzyme is involved in biosynthesis of GDP-D-glycero-α-D-manno-heptose, which is required for assembly of S-layer glycoprotein in Gram-positive bacteria. The enzyme is specific for the α-anomer.
References:
1.  Kneidinger, B., Graninger, M., Puchberger, M., Kosma, P. and Messner, P. Biosynthesis of nucleotide-activated D-glycero-D-manno-heptose. J. Biol. Chem. 276 (2001) 20935–20944. [PMID: 11279237]
2.  Valvano, M.A., Messner, P. and Kosma, P. Novel pathways for biosynthesis of nucleotide-activated glycero-manno-heptose precursors of bacterial glycoproteins and cell surface polysaccharides. Microbiology 148 (2002) 1979–1989. [PMID: 12101286]
[EC 2.7.1.168 created 2010]
 
 
EC 2.4.99.15     Relevance: 16.4%
Accepted name: (Kdo)3-lipid IVA (2-4) 3-deoxy-D-manno-octulosonic acid transferase
Reaction: α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA + CMP-β-Kdo = α-Kdo-(2→8)-[α-Kdo-(2→4)]-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA + CMP
Glossary: (Kdo)3-lipid IVA = α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→8)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
(Kdo)4-lipid IVA = α-Kdo-(2→8)-[α-Kdo-(2→4)]-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→8)-[(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)]-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
CMP-β-Kdo = CMP-3-deoxy-β-D-manno-oct-2-ulopyranosylonate
Other name(s): Kdo transferase; waaA (gene name); kdtA (gene name); 3-deoxy-D-manno-oct-2-ulosonic acid transferase; 3-deoxy-manno-octulosonic acid transferase; (KDO)3-lipid IVA (2-4) 3-deoxy-D-manno-octulosonic acid transferase
Systematic name: CMP-3-deoxy-D-manno-oct-2-ulosonate:(Kdo)3-lipid IVA 3-deoxy-D-manno-oct-2-ulosonate transferase [(2→4) glycosidic bond-forming]
Comments: The enzyme from Chlamydia psittaci transfers four Kdo residues to lipid A, forming a branched tetrasaccharide with the structure α-Kdo-(2,8)-[α-Kdo-(2,4)]-α-Kdo-(2,4)-α-Kdo (cf. EC 2.4.99.12 [lipid IVA 3-deoxy-D-manno-octulosonic acid transferase], EC 2.4.99.13 [(Kdo)-lipid IVA 3-deoxy-D-manno-octulosonic acid transferase], and EC 2.4.99.14 [(Kdo)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase]).
References:
1.  Brabetz, W., Lindner, B. and Brade, H. Comparative analyses of secondary gene products of 3-deoxy-D-manno-oct-2-ulosonic acid transferases from Chlamydiaceae in Escherichia coli K-12. Eur. J. Biochem. 267 (2000) 5458–5465. [PMID: 10951204]
2.  Holst, O., Bock, K., Brade, L. and Brade, H. The structures of oligosaccharide bisphosphates isolated from the lipopolysaccharide of a recombinant Escherichia coli strain expressing the gene gseA [3-deoxy-D-manno-octulopyranosonic acid (Kdo) transferase] of Chlamydia psittaci 6BC. Eur. J. Biochem. 229 (1995) 194–200. [PMID: 7744029]
[EC 2.4.99.15 created 2010, modified 2011]
 
 
EC 4.2.3.138     Relevance: 16.4%
Accepted name: (+)-epi-α-bisabolol synthase
Reaction: (2E,6E)-farnesyl diphosphate + H2O = (+)-epi-α-bisabolol + diphosphate
Glossary: (+)-epi-α-bisabolol = (2S)-6-methyl-2-[(1R)-4-methylcyclohex-3-en-1-yl]hept-5-en-2-ol
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase (cyclizing, (+)-epi-α-bisabolol-forming)
Comments: Isolated from the plant Phyla dulcis (Aztec sweet herb). (+)-epi-α-Bisabolol is the precursor of the sweetener hernandulcin.
References:
1.  Attia, M., Kim, S.U. and Ro, D.K. Molecular cloning and characterization of (+)-epi-α-bisabolol synthase, catalyzing the first step in the biosynthesis of the natural sweetener, hernandulcin, in Lippia dulcis. Arch. Biochem. Biophys. 527 (2012) 37–44. [PMID: 22867794]
[EC 4.2.3.138 created 2012]
 
 
EC 2.4.1.290     Relevance: 16.4%
Accepted name: N,N′-diacetylbacillosaminyl-diphospho-undecaprenol α-1,3-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + N,N′-diacetyl-α-D-bacillosaminyl-diphospho-tritrans,heptacis-undecaprenol = UDP + N-acetyl-D-galactosaminyl-α-(1→3)-N,N′-diacetyl-α-D-bacillosaminyl-diphospho-tritrans,heptacis-undecaprenol
Glossary: N,N′-diacetyl-D-bacillosamine = 2,4-diacetamido-2,4,6-trideoxy-D-glucopyranose
Other name(s): PglA
Systematic name: UDP-N-acetyl-α-D-galactosamine:N,N′-diacetyl-α-D-bacillosaminyl-diphospho-tritrans,heptacis-undecaprenol 3-α-N-acetyl-D-galactosaminyltransferase
Comments: Isolated from Campylobacter jejuni. Part of a bacterial N-linked glycosylation pathway.
References:
1.  Glover, K.J., Weerapana, E. and Imperiali, B. In vitro assembly of the undecaprenylpyrophosphate-linked heptasaccharide for prokaryotic N-linked glycosylation. Proc. Natl. Acad. Sci. USA 102 (2005) 14255–14259. [PMID: 16186480]
[EC 2.4.1.290 created 2012]
 
 
EC 3.2.1.190     Relevance: 16.4%
Accepted name: dioscin glycosidase (3-O-β-D-Glc-diosgenin-forming)
Reaction: 3-O-[α-L-Rha-(1→4)-[α-L-Rha-(1→2)]-β-D-Glc]diosgenin + 2 H2O = 2 L-rhamnopyranose + diosgenin 3-O-β-D-glucopyranoside
Glossary: 3-O-[α-L-Rha-(1→4)-[α-L-Rha-(1→2)]-β-D-Glc]diosgenin = (3β,25R)-spirost-5-en-3-yl 6-deoxy-α-L-mannopyranosyl-(1→2)-[6-deoxy-α-L-mannopyranosyl-(1→4)]-β-D-glucopyranoside = dioscin
diosgenin = (3β,25R)-spirost-5-en-3-ol
Other name(s): dioscin-α-L-rhamnosidase
Systematic name: 3-O-[α-L-Rha-(1→4)-[α-L-Rha-(1→2)]-β-D-Glc]diosgenin (3-O-β-D-Glc-diosgenin-forming)
Comments: The enzyme is involved in the hydrolysis of the steroid saponin dioscin by the digestive system of Sus scrofa (pig). cf. EC 3.2.1.189, dioscin glycosidase (diosgenin-forming).
References:
1.  Qian, S., Yu, H., Zhang, C., Lu, M., Wang, H. and Jin, F. Purification and characterization of dioscin-α-L-rhamnosidase from pig liver. Chem Pharm Bull (Tokyo) 53 (2005) 911–914. [PMID: 16079518]
[EC 3.2.1.190 created 2013]
 
 
EC 4.2.2.23     Relevance: 16.4%
Accepted name: rhamnogalacturonan endolyase
Reaction: Endotype eliminative cleavage of L-α-rhamnopyranosyl-(1→4)-α-D-galactopyranosyluronic acid bonds of rhamnogalacturonan I domains in ramified hairy regions of pectin leaving L-rhamnopyranose at the reducing end and 4-deoxy-4,5-unsaturated D-galactopyranosyluronic acid at the non-reducing end.
Other name(s): rhamnogalacturonase B; α-L-rhamnopyranosyl-(1→4)-α-D-galactopyranosyluronide lyase; Rgase B; rhamnogalacturonan α-L-rhamnopyranosyl-(1,4)-α-D-galactopyranosyluronide lyase; RG-lyase; YesW; RGL4; Rgl11A; Rgl11Y; RhiE
Systematic name: α-L-rhamnopyranosyl-(1→4)-α-D-galactopyranosyluronate endolyase
Comments: The enzyme is part of the degradation system for rhamnogalacturonan I in Bacillus subtilis strain 168 and Aspergillus aculeatus.
References:
1.  Mutter, M., Colquhoun, I.J., Schols, H.A., Beldman, G. and Voragen, A.G. Rhamnogalacturonase B from Aspergillus aculeatus is a rhamnogalacturonan α-L-rhamnopyranosyl-(1→4)-α-D-galactopyranosyluronide lyase. Plant Physiol. 110 (1996) 73–77. [PMID: 8587995]
2.  Azadi, P., O'Neill, M.A., Bergmann, C., Darvill, A.G. and Albersheim, P. The backbone of the pectic polysaccharide rhamnogalacturonan I is cleaved by an endohydrolase and an endolyase. Glycobiology 5 (1995) 783–789. [PMID: 8720076]
3.  Mutter, M., Colquhoun, I.J., Beldman, G., Schols, H.A., Bakx, E.J. and Voragen, A.G. Characterization of recombinant rhamnogalacturonan α-L-rhamnopyranosyl-(1,4)-α-D-galactopyranosyluronide lyase from Aspergillus aculeatus. An enzyme that fragments rhamnogalacturonan I regions of pectin. Plant Physiol. 117 (1998) 141–152. [PMID: 9576783]
4.  Kadirvelraj, R., Harris, P., Poulsen, J.C., Kauppinen, S. and Larsen, S. A stepwise optimization of crystals of rhamnogalacturonan lyase from Aspergillus aculeatus. Acta Crystallogr. D Biol. Crystallogr. 58 (2002) 1346–1349. [PMID: 12136151]
5.  Laatu, M. and Condemine, G. Rhamnogalacturonate lyase RhiE is secreted by the out system in Erwinia chrysanthemi. J. Bacteriol. 185 (2003) 1642–1649. [PMID: 12591882]
6.  Pages, S., Valette, O., Abdou, L., Belaich, A. and Belaich, J.P. A rhamnogalacturonan lyase in the Clostridium cellulolyticum cellulosome. J. Bacteriol. 185 (2003) 4727–4733. [PMID: 12896991]
7.  Ochiai, A., Yamasaki, M., Itoh, T., Mikami, B., Hashimoto, W. and Murata, K. Crystallization and preliminary X-ray analysis of the rhamnogalacturonan lyase YesW from Bacillus subtilis strain 168, a member of polysaccharide lyase family 11. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 62 (2006) 438–440. [PMID: 16682770]
8.  Jensen, M.H., Otten, H., Christensen, U., Borchert, T.V., Christensen, L.L., Larsen, S. and Leggio, L.L. Structural and biochemical studies elucidate the mechanism of rhamnogalacturonan lyase from Aspergillus aculeatus. J. Mol. Biol. 404 (2010) 100–111. [PMID: 20851126]
[EC 4.2.2.23 created 2011]
 
 
EC 2.4.1.87     Relevance: 16.3%
Accepted name: N-acetyllactosaminide 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R = UDP + α-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-N-acetylglucosaminyl-R (where R can be OH, an oligosaccharide or a glycoconjugate)
Other name(s): α-galactosyltransferase; UDP-Gal:β-D-Gal(1,4)-D-GlcNAc α(1,3)-galactosyltransferase; UDP-Gal:N-acetyllactosaminide α(1,3)-galactosyltransferase; UDP-Gal:N-acetyllactosaminide α-1,3-D-galactosyltransferase; UDP-Gal:Galβ1→4GlcNAc-R α1→3-galactosyltransferase; UDP-galactose-acetyllactosamine α-D-galactosyltransferase; UDPgalactose:β-D-galactosyl-β-1,4-N-acetyl-D-glucosaminyl-glycopeptide α-1,3-D-galactosyltransferase; glucosaminylglycopeptide α-1,3-galactosyltransferase; uridine diphosphogalactose-acetyllactosamine α1→3-galactosyltransferase; uridine diphosphogalactose-acetyllactosamine galactosyltransferase; uridine diphosphogalactose-galactosylacetylglucosaminylgalactosylglucosylceramide galactosyltransferase; β-D-galactosyl-N-acetylglucosaminylglycopeptide α-1,3-galactosyltransferase; UDP-galactose:N-acetyllactosaminide 3-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-1,4-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase
Comments: Acts on β-galactosyl-1,4-N-acetylglucosaminyl termini on asialo-α1-acid glycoprotein and N-acetyllactosamine (β-D-galactosyl-1,4-N-acetyl-β-D-glucosamine), but not on 2′-fucosylated-N-acetyllactosamine. The non-reducing terminal N-acetyllactosamine residues of glycoproteins can also act as acceptor. Now includes EC 2.4.1.124 and EC 2.4.1.151.
References:
1.  Basu, M. and Basu, S. Enzymatic synthesis of a blood group B-related pentaglycosylceramide by an α-galactosyltransferase from rabbit bone marrow. J. Biol. Chem. 248 (1973) 1700–1706. [PMID: 4632915]
2.  Blanken, W.M. and van den Eijnden, D.H. Biosynthesis of terminal Gal α 1→3Gal β 1→4GlcNAc-R oligosaccharide sequences on glycoconjugates. Purification and acceptor specificity of a UDP-Gal:N-acetyllactosaminide α 1→3-galactosyltransferase from calf thymus. J. Biol. Chem. 260 (1985) 12927–12934. [PMID: 3932335]
3.  Blake, D.A. and Goldstein, I.J. An α-D-galactosyltransferase activity in Ehrlich ascites tumor cells. Biosynthesis and characterization of a trisaccharide (α-D-galactose-(1→3)-N-acetyllactosamine). J. Biol. Chem. 256 (1981) 5387–5393. [PMID: 6787040]
[EC 2.4.1.87 created 1976, modified 1989, modified 2002 (EC 2.4.1.124 created 1984, incorporated 2002, EC 2.4.1.151 created 1984, incorporated 2002)]
 
 
EC 3.2.1.177     Relevance: 16.3%
Accepted name: α-D-xyloside xylohydrolase
Reaction: Hydrolysis of terminal, non-reducing α-D-xylose residues with release of α-D-xylose.
Other name(s): α-xylosidase
Systematic name: α-D-xyloside xylohydrolase
Comments: The enzyme catalyses hydrolysis of a terminal, unsubstituted xyloside at the extreme reducing end of a xylogluco-oligosaccharide. Representative α-xylosidases from glycoside hydrolase family 31 utilize a two-step (double-displacement) mechanism involving a covalent glycosyl-enzyme intermediate, and retain the anomeric configuration of the product.
References:
1.  Moracci, M., Cobucci Ponzano, B., Trincone, A., Fusco, S., De Rosa, M., van Der Oost, J., Sensen, C.W., Charlebois, R.L. and Rossi, M. Identification and molecular characterization of the first α -xylosidase from an archaeon. J. Biol. Chem. 275 (2000) 22082–22089. [PMID: 10801892]
2.  Sampedro, J., Sieiro, C., Revilla, G., Gonzalez-Villa, T. and Zarra, I. Cloning and expression pattern of a gene encoding an α-xylosidase active against xyloglucan oligosaccharides from Arabidopsis. Plant Physiol. 126 (2001) 910–920. [PMID: 11402218]
3.  Crombie, H.J., Chengappa, S., Jarman, C., Sidebottom, C. and Reid, J.S. Molecular characterisation of a xyloglucan oligosaccharide-acting α-D-xylosidase from nasturtium (Tropaeolum majus L.) cotyledons that resembles plant ’apoplastic’ α-D-glucosidases. Planta 214 (2002) 406–413. [PMID: 11859845]
4.  Lovering, A.L., Lee, S.S., Kim, Y.W., Withers, S.G. and Strynadka, N.C. Mechanistic and structural analysis of a family 31 α-glycosidase and its glycosyl-enzyme intermediate. J. Biol. Chem. 280 (2005) 2105–2115. [PMID: 15501829]
5.  Iglesias, N., Abelenda, J.A., Rodino, M., Sampedro, J., Revilla, G. and Zarra, I. Apoplastic glycosidases active against xyloglucan oligosaccharides of Arabidopsis thaliana. Plant Cell Physiol. 47 (2006) 55–63. [PMID: 16267099]
6.  Okuyama, M., Kaneko, A., Mori, H., Chiba, S. and Kimura, A. Structural elements to convert Escherichia coli α-xylosidase (YicI) into α-glucosidase. FEBS Lett. 580 (2006) 2707–2711. [PMID: 16631751]
7.  Larsbrink, J., Izumi, A., Ibatullin, F., Nakhai, A., Gilbert, H.J., Davies, G.J. and Brumer, H. Structural and enzymatic characterisation of a glycoside hydrolase family 31 α-xylosidase from Cellvibrio japonicus involved in xyloglucan saccharification. Biochem. J. 436 (2011) 567–580. [PMID: 21426303]
[EC 3.2.1.177 created 2011]
 
 
EC 3.2.1.199     Relevance: 16.3%
Accepted name: sulfoquinovosidase
Reaction: a 6-sulfo-α-D-quinovosyl diacylglycerol + H2O = 6-sulfo-α-D-quinovose + a 1,2-diacylglycerol
Glossary: quinovose = 6-deoxy-D-glucopyranose
Other name(s): yihQ (gene name); 6-sulfo-α-D-quinovosyl diacylglycerol 6-sulfo-D-quinovohydrolase
Systematic name: 6-sulfo-α-D-quinovosyl diacylglycerol 6-sulfo-D-quinovohydrolase (configuration-retaining)
Comments: The enzyme, characterized from the bacteria Escherichia coli and Pseudomonas putida, hydrolyses terminal non-reducing α-sulfoquinovoside residues in α-sulfoquinovosyl diacylglycerides and α-sulfoquinovosyl glycerol using a retaining mechanism. The enzyme belongs to the glycosyl hydrolase GH31 family.
References:
1.  Shibuya, I. and Benson, A. A. Hydrolysis of α-sulphoquinovosides by β-galactosidase. Nature 192 (1961) 1186–1187.
2.  Speciale, G., Jin, Y., Davies, G.J., Williams, S.J. and Goddard-Borger, E.D. YihQ is a sulfoquinovosidase that cleaves sulfoquinovosyl diacylglyceride sulfolipids. Nat. Chem. Biol. 12 (2016) 215–217. [PMID: 26878550]
[EC 3.2.1.199 created 2016]
 
 
EC 3.2.1.63     Relevance: 16.3%
Accepted name: 1,2-α-L-fucosidase
Reaction: methyl-2-α-L-fucopyranosyl-β-D-galactoside + H2O = L-fucose + methyl β-D-galactoside
Other name(s): almond emulsin fucosidase; α-(1→2)-L-fucosidase
Systematic name: 2-α-L-fucopyranosyl-β-D-galactoside fucohydrolase
Comments: Highly specific for non-reducing terminal L-fucose residues linked to D-galactose residues by a 1,2-α-linkage. Not identical with EC 3.2.1.111 1,3-α-L-fucosidase.
References:
1.  Bahl, O.P. Glycosidases of Aspergillus niger. II. Purification and general properties of 1,2-α-L-fucosidase. J. Biol. Chem. 245 (1970) 299–304. [PMID: 5460888]
2.  Ogata-Arakawa, M., Muramatsu, T. and Kobata, A. α-L-Fucosidases from almond emulsin: characterization of the two enzymes with different specificities. Arch. Biochem. Biophys. 181 (1977) 353–358. [PMID: 18111]
3.  Reglero, A. and Cabezas, J.A. Glycosidases of molluscs. Purification and properties of α-L-fucosidase from Chamelea gallina L. Eur. J. Biochem. 66 (1976) 379–387. [PMID: 7458]
[EC 3.2.1.63 created 1972]
 
 
EC 2.4.2.61     Relevance: 16.3%
Accepted name: α-dystroglycan β1,4-xylosyltransferase
Reaction: UDP-α-D-xylose + 3-O-[Rib-ol-P-Rib-ol-P-3-β-D-GalNAc-(1→3)-β-D-GlcNAc-(1→4)-O-6-P-α-D-Man]-Ser/Thr-[protein] = UDP + 3-O-[β-D-Xyl-(1→4)-Rib-ol-P-Rib-ol-P-3-β-D-GalNAc-(1→3)-β-D-GlcNAc-(1→4)-O-6-P-α-D-Man]-Ser/Thr-[protein]
Other name(s): TMEM5 (gene name)
Systematic name: UDP-α-D-xylose:3-O-[Rib-ol-P-Rib-ol-P-3-β-D-GalNAc-(1→3)-β-D-GlcNAc-(1→4)-O-6-P-α-D-Man]-Ser/Thr-[protein] xylosyltransferase
Comments: This eukaryotic enzyme catalyses a step in the biosynthesis of the glycan moiety of the membrane protein α-dystroglycan. It is specific for the second ribitol 5-phosphate in the nascent glycan chain as acceptor.
References:
1.  Vuillaumier-Barrot, S., Bouchet-Seraphin, C., Chelbi, M., Devisme, L., Quentin, S., Gazal, S., Laquerriere, A., Fallet-Bianco, C., Loget, P., Odent, S., Carles, D., Bazin, A., Aziza, J., Clemenson, A., Guimiot, F., Bonniere, M., Monnot, S., Bole-Feysot, C., Bernard, J.P., Loeuillet, L., Gonzales, M., Socha, K., Grandchamp, B., Attie-Bitach, T., Encha-Razavi, F. and Seta, N. Identification of mutations in TMEM5 and ISPD as a cause of severe cobblestone lissencephaly. Am. J. Hum. Genet. 91 (2012) 1135–1143. [PMID: 23217329]
2.  Manya, H., Yamaguchi, Y., Kanagawa, M., Kobayashi, K., Tajiri, M., Akasaka-Manya, K., Kawakami, H., Mizuno, M., Wada, Y., Toda, T. and Endo, T. The muscular dystrophy gene TMEM5 encodes a ribitol β1,4-xylosyltransferase required for the functional glycosylation of dystroglycan. J. Biol. Chem. 291 (2016) 24618–24627. [PMID: 27733679]
[EC 2.4.2.61 created 2018]
 
 
EC 1.1.1.135     Relevance: 16.3%
Accepted name: GDP-6-deoxy-D-talose 4-dehydrogenase
Reaction: GDP-6-deoxy-α-D-talose + NAD(P)+ = GDP-4-dehydro-α-D-rhamnose + NAD(P)H + H+
Glossary: GDP-4-dehydro-α-D-rhamnose = GDP-4-dehydro-6-deoxy-α-D-mannose
GDP-6-deoxy-α-D-talose = GDP-α-D-pneumose
Other name(s): guanosine diphospho-6-deoxy-D-talose dehydrogenase; GDP-6-deoxy-D-talose:NAD(P)+ 4-oxidoreductase
Systematic name: GDP-6-deoxy-α-D-talose:NAD(P)+ 4-oxidoreductase
References:
1.  Markovitz, A. Biosynthesis of guanosine diphosphate D-rhamnose and guanosine diphosphate D-talomethylose from guanosine diphosphate α-D-mannose. J. Biol. Chem. 239 (1964) 2091–2098. [PMID: 14209931]
[EC 1.1.1.135 created 1972, modified 1976]
 
 
EC 2.4.2.42     Relevance: 16.3%
Accepted name: UDP-D-xylose:β-D-glucoside α-1,3-D-xylosyltransferase
Reaction: UDP-α-D-xylose + [protein with EGF-like domain]-3-O-(β-D-glucosyl)-L-serine = UDP + [protein with EGF-like domain]-3-O-[α-D-xylosyl-(1→3)-β-D-glucosyl]-L-serine
Other name(s): β-glucoside α-1,3-xylosyltransferase; UDP-α-D-xylose:β-D-glucoside 3-α-D-xylosyltransferase; GXYLT1 (gene name); GXYLT2 (gene name)
Systematic name: UDP-α-D-xylose:[protein with EGF-like domain]-3-O-(β-D-glucosyl)-L-serine 3-α-D-xylosyltransferase (configuration-retaining)
Comments: The enzyme, found in animals and insects, is involved in the biosynthesis of the α-D-xylosyl-(1→3)-α-D-xylosyl-(1→3)-β-D-glucosyl trisaccharide on epidermal growth factor-like (EGF-like) domains [2,3]. When present on Notch proteins, the trisaccharide functions as a modulator of the signalling activity of this protein.
References:
1.  Omichi, K., Aoki, K., Minamida, S. and Hase, S. Presence of UDP-D-xylose: β-D-glucoside α-1,3-D-xylosyltransferase involved in the biosynthesis of the Xyl α 1-3Glc β-Ser structure of glycoproteins in the human hepatoma cell line HepG2. Eur. J. Biochem. 245 (1997) 143–146. [PMID: 9128735]
2.  Ishimizu, T., Sano, K., Uchida, T., Teshima, H., Omichi, K., Hojo, H., Nakahara, Y. and Hase, S. Purification and substrate specificity of UDP-D-xylose:β-D-glucoside α-1,3-D-xylosyltransferase involved in the biosynthesis of the Xyl α1-3Xyl α1-3Glc β1-O-Ser on epidermal growth factor-like domains. J. Biochem. 141 (2007) 593–600. [PMID: 17317689]
3.  Sethi, M.K., Buettner, F.F., Krylov, V.B., Takeuchi, H., Nifantiev, N.E., Haltiwanger, R.S., Gerardy-Schahn, R. and Bakker, H. Identification of glycosyltransferase 8 family members as xylosyltransferases acting on O-glucosylated notch epidermal growth factor repeats. J. Biol. Chem. 285 (2010) 1582–1586. [PMID: 19940119]
[EC 2.4.2.42 created 2010, modified 2020]
 
 
EC 2.4.1.57      
Deleted entry: phosphatidylinositol α-mannosyltransferase. Newer studies have shown that this is catalysed by two independent activities now covered by EC 2.4.1.345, phosphatidyl-myo-inositol α-mannosyl transferase and EC 2.4.1.346, phosphatidyl-myo-inositol dimannoside synthase
[EC 2.4.1.57 created 1972, modified 2003, deleted 2017]
 
 
EC 2.7.1.212     Relevance: 16.2%
Accepted name: α-D-ribose-1-phosphate 5-kinase (ADP)
Reaction: ADP + α-D-ribose-1-phosphate = AMP + α-D-ribose 1,5-bisphosphate
Systematic name: ADP:α-D-ribose-1-phosphate 5-phosphotransferase
Comments: The enzyme, characterized from the archaeon Thermococcus kodakarensis, participates in an archaeal pathway for nucleoside degradation.
References:
1.  Aono, R., Sato, T., Imanaka, T. and Atomi, H. A pentose bisphosphate pathway for nucleoside degradation in Archaea. Nat. Chem. Biol. 11 (2015) 355–360. [PMID: 25822915]
[EC 2.7.1.212 created 2016]
 
 
EC 2.4.1.345     Relevance: 16.2%
Accepted name: phosphatidyl-myo-inositol α-mannosyltransferase
Reaction: GDP-α-D-mannose + 1-phosphatidyl-1D-myo-inositol = GDP + 2-O-(α-D-mannosyl)-1-phosphatidyl-1D-myo-inositol
Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns
Other name(s): mannosyltransferase PimA; PimA; guanosine diphosphomannose-phosphatidyl-inositol α-mannosyltransferase (ambiguous)
Systematic name: GDP-α-D-mannose:1-phosphatidyl-1D-myo-inositol 2-α-D-mannosyltransferase (configuration-retaining)
Comments: Requires Mg2+. The enzyme, found in Corynebacteriales, is involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs).
References:
1.  Kordulakova, J., Gilleron, M., Mikusova, K., Puzo, G., Brennan, P.J., Gicquel, B. and Jackson, M. Definition of the first mannosylation step in phosphatidylinositol mannoside synthesis. PimA is essential for growth of mycobacteria. J. Biol. Chem. 277 (2002) 31335–31344. [PMID: 12068013]
2.  Gu, X., Chen, M., Wang, Q., Zhang, M., Wang, B. and Wang, H. Expression and purification of a functionally active recombinant GDP-mannosyltransferase (PimA) from Mycobacterium tuberculosis H37Rv. Protein Expr. Purif. 42 (2005) 47–53. [PMID: 15939292]
3.  Giganti, D., Albesa-Jove, D., Urresti, S., Rodrigo-Unzueta, A., Martinez, M.A., Comino, N., Barilone, N., Bellinzoni, M., Chenal, A., Guerin, M.E. and Alzari, P.M. Secondary structure reshuffling modulates glycosyltransferase function at the membrane. Nat. Chem. Biol. 11 (2015) 16–18. [PMID: 25402770]
4.  Rodrigo-Unzueta, A., Martinez, M.A., Comino, N., Alzari, P.M., Chenal, A. and Guerin, M.E. Molecular basis of membrane association by the phosphatidylinositol mannosyltransferase PimA enzyme from Mycobacteria. J. Biol. Chem. 291 (2016) 13955–13963. [PMID: 27189944]
[EC 2.4.1.345 created 2017]
 
 
EC 2.6.1.109     Relevance: 16.1%
Accepted name: 8-amino-3,8-dideoxy-α-D-manno-octulosonate transaminase
Reaction: 8-amino-3,8-dideoxy-α-D-manno-octulosonate + 2-oxoglutarate = 8-dehydro-3-deoxy-α-D-manno-octulosonate + L-glutamate
Glossary: 3-deoxy-α-D-manno-octulosonate = Kdo
8-dehydro-3-deoxy-α-D-manno-octulosonate = (2R,4R,5R,6S)-2,4,5-trihydroxy-6-[(1S)-1-hydroxy-2-oxoethyl]oxane-2-carboxylate
Other name(s): kdnA (gene name)
Systematic name: 8-amino-3,8-dideoxy-α-D-manno-octulosonate:2-oxoglutarate aminotransferase
Comments: The enzyme, characterized from the bacterium Shewanella oneidensis, forms 8-amino-3,8-dideoxy-α-D-manno-octulosonate, an aminated form of Kdo found in lipopolysaccharides of members of the Shewanella genus. cf. EC 1.1.3.48, 3-deoxy-α-D-manno-octulosonate 8-oxidase.
References:
1.  Gattis, S.G., Chung, H.S., Trent, M.S. and Raetz, C.R. The origin of 8-amino-3,8-dideoxy-D-manno-octulosonic acid (Kdo8N) in the lipopolysaccharide of Shewanella oneidensis. J. Biol. Chem. 288 (2013) 9216–9225. [PMID: 23413030]
[EC 2.6.1.109 created 2015]
 
 
EC 2.4.1.21     Relevance: 16.1%
Accepted name: starch synthase (glycosyl-transferring)
Reaction: ADP-α-D-glucose + [(1→4)-α-D-glucosyl]n = ADP + [(1→4)-α-D-glucosyl]n+1
Other name(s): ADP-glucose—starch glucosyltransferase; adenosine diphosphate glucose-starch glucosyltransferase; adenosine diphosphoglucose-starch glucosyltransferase; ADP-glucose starch synthase; ADP-glucose transglucosylase; ADP-glucose-starch glucosyltransferase; ADPG starch synthetase; ADPG-starch glucosyltransferase; starch synthetase; ADP-glucose:1,4-α-D-glucan 4-α-D-glucosyltransferase
Systematic name: ADP-α-D-glucose:(1→4)-α-D-glucan 4-α-D-glucosyltransferase
Comments: The accepted name varies according to the source of the enzyme and the nature of its synthetic product, e.g. starch synthase, bacterial glycogen synthase. Similar to EC 2.4.1.11 [glycogen(starch) synthase] but the preferred or mandatory nucleoside diphosphate sugar substrate is ADP-α-D-glucose. The entry covers starch and glycogen synthases utilizing ADP-α-D-glucose.
References:
1.  Chambers, J.C. and Elbein, A.D. Biosynthesis of glucans in mung bean seedlings. Formation of β-(1,4)-glucans from GDP-glucose and β-(1,3)-glucans from UDP-glucose. Arch. Biochem. Biophys. 138 (1970) 620–631. [PMID: 4317490]
2.  Frydman, R.B. and Cardini, C.E. Studies on adenosine diphosphate D-glucose: α-1,4-glucan α-4-glucosyltransferase of sweet-corn endosperm. Biochim. Biophys. Acta 96 (1965) 294–303. [PMID: 14298833]
3.  Greenberg, E. and Preiss, J. Biosynthesis of bacterial glycogen. II. Purification and properties of the adenosine diphosphoglucose:glycogen transglucosylase of arthrobacter species NRRL B1973. J. Biol. Chem. 240 (1965) 2341–2348. [PMID: 14304835]
4.  Leloir, L.F., de Fekete, M.A. and Cardini, C.E. Starch and oligosaccharide synthesis from uridine diphosphate glucose. J. Biol. Chem. 236 (1961) 636–641. [PMID: 13760681]
5.  Preiss, J., Govins, S., Eidels, L., Lammel, C., Greenberg, E., Edelmann, P. and Sabraw, A. Regulatory mechanisms in the biosynthesis of α-1,4-glucans in bacteria and plants. In: Whelan, W.J. and Schultz, J. (Ed.), Miami Winter Symposia, vol. 1, North Holland, Utrecht, 1970, pp. 122–138.
[EC 2.4.1.21 created 1965]
 
 
EC 2.3.1.284     Relevance: 16.1%
Accepted name: 3′-(hydroxy)phthioceranyl-2′-palmitoyl(stearoyl)-2-O-sulfo-trehalose (hydroxy)phthioceranyltransferase
Reaction: 3 3′-(hydroxy)phthioceranyl-2′-palmitoyl(stearoyl)-2-O-sulfo-α,α-trehalose = 3,6,6′-tris-(hydroxy)phthioceranyl-2-palmitoyl(stearoyl)-2′-sulfo-α-alpha-trehalose + 2 2′-palmitoyl/stearoyl-2-O-sulfo-α,α-trehalose
Glossary: 3,6,6′-tris-(hydroxy)phthioceranyl-2-palmitoyl(stearoyl)-2′-sulfo-α-alpha-trehalose = a mycobacterial sulfolipid
Other name(s): chp1 (gene name)
Systematic name: 3′-(hydroxy)phthioceranyl-2′-palmitoyl(stearoyl)-2-O-sulfo-α,α-trehalose:3′-(hydroxy)phthioceranyl-2′-palmitoyl(stearoyl)-2-O-sulfo-α,α-trehalose 6,6′-di(hydroxy)phthioceranyltransferase
Comments: The enzyme, present in mycobacteria, catalyses the ultimate step in the biosynthesis of mycobacterial sulfolipids. It catalyses two successive transfers of a (hydroxy)phthioceranyl group from two diacylated intermediates to third diacylated intermediate, generating the tetraacylated sulfolipid.
References:
1.  Seeliger, J.C., Holsclaw, C.M., Schelle, M.W., Botyanszki, Z., Gilmore, S.A., Tully, S.E., Niederweis, M., Cravatt, B.F., Leary, J.A. and Bertozzi, C.R. Elucidation and chemical modulation of sulfolipid-1 biosynthesis in Mycobacterium tuberculosis. J. Biol. Chem. 287 (2012) 7990–8000. [PMID: 22194604]
[EC 2.3.1.284 created 2019]
 
 
EC 2.4.1.155     Relevance: 16.1%
Accepted name: α-1,6-mannosyl-glycoprotein 6-β-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-GlcNAc-(1→2)-[β-D-GlcNAc-(1→4)]-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein] = UDP + β-D-GlcNAc-(1→2)-[β-D-GlcNAc-(1→4)]-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-[β-D-GlcNAc-(1→6)]-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein]
Other name(s): MGAT5 (gene name); N-acetylglucosaminyltransferase V; α-mannoside β-1,6-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-α-mannoside β1→6-acetylglucosaminyltransferase; UDP-N-acetylglucosamine:α-mannoside-β1,6 N-acetylglucosaminyltransferase; α-1,3(6)-mannosylglycoprotein β-1,6-N-acetylglucosaminyltransferase; GnTV; GlcNAc-T V; UDP-N-acetyl-D-glucosamine:6-[2-(N-acetyl-β-D-glucosaminyl)-α-D-mannosyl]-glycoprotein 6-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→6)-β-D-mannosyl-glycoprotein 6-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: Requires Mg2+. The enzyme, found in vertebrates, participates in the processing of N-glycans in the Golgi apparatus. It catalyses the addition of N-acetylglucosamine in β 1-6 linkage to the α-linked mannose of biantennary N-linked oligosaccharides, and thus enables the synthesis of tri- and tetra-antennary complexes.
References:
1.  Cummings, R.D., Trowbridge, I.S. and Kornfeld, S. A mouse lymphoma cell line resistant to the leukoagglutinating lectin from Phaseolus vulgaris is deficient in UDP-GlcNAc: α-D-mannoside β1,6 N-acetylglucosaminyltransferase. J. Biol. Chem. 257 (1982) 13421–13427. [PMID: 6216250]
2.  Hindsgaul, O., Tahir, S.H., Srivastava, O.P. and Pierce, M. The trisaccharide β-D-GlcpNAc-(1→2)-α-D-Manp-(1→6)-β-D-Manp, as its 8-methoxycarbonyloctyl glycoside, is an acceptor selective for N-acetylglucosaminyltransferase V. Carbohydr. Res. 173 (1988) 263–272. [PMID: 2834054]
3.  Shoreibah, M.G., Hindsgaul, O. and Pierce, M. Purification and characterization of rat kidney UDP-N-acetylglucosamine: α-6-D-mannoside β-1,6-N-acetylglucosaminyltransferase. J. Biol. Chem. 267 (1992) 2920–2927. [PMID: 1531335]
4.  Gu, J., Nishikawa, A., Tsuruoka, N., Ohno, M., Yamaguchi, N., Kangawa, K. and Taniguchi, N. Purification and characterization of UDP-N-acetylglucosamine: α-6-D-mannoside β 1-6N-acetylglucosaminyltransferase (N-acetylglucosaminyltransferase V) from a human lung cancer cell line. J. Biochem. 113 (1993) 614–619. [PMID: 8393437]
5.  Park, C., Jin, U.H., Lee, Y.C., Cho, T.J. and Kim, C.H. Characterization of UDP-N-acetylglucosamine:α-6-D-mannoside β-1,6-N-acetylglucosaminyltransferase V from a human hepatoma cell line Hep3B. Arch. Biochem. Biophys. 367 (1999) 281–288. [PMID: 10395745]
6.  Saito, T., Miyoshi, E., Sasai, K., Nakano, N., Eguchi, H., Honke, K. and Taniguchi, N. A secreted type of β 1,6-N-acetylglucosaminyltransferase V (GnT-V) induces tumor angiogenesis without mediation of glycosylation: a novel function of GnT-V distinct from the original glycosyltransferase activity. J. Biol. Chem. 277 (2002) 17002–17008. [PMID: 11872751]
[EC 2.4.1.155 created 1986, modified 2001, modified 2018]
 
 
EC 5.5.1.10     Relevance: 16.1%
Accepted name: α-pinene-oxide decyclase
Reaction: α-pinene oxide = (Z)-2-methyl-5-isopropylhexa-2,5-dienal
Other name(s): α-pinene oxide lyase; α-pinene-oxide lyase (decyclizing)
Systematic name: α-pinene-oxide lyase (ring-opening)
Comments: Both rings of pinene are cleaved in the reaction.
References:
1.  Griffiths, E.T., Harries, P.C., Jeffcoat, R. and Trudgill, P.W. Purification and properties of α-pinene oxide lyase from Nocardia sp. strain P18.3. J. Bacteriol. 169 (1987) 4980–4983. [PMID: 3667522]
[EC 5.5.1.10 created 1990]
 
 
EC 5.4.99.9     Relevance: 16.1%
Accepted name: UDP-galactopyranose mutase
Reaction: UDP-α-D-galactopyranose = UDP-α-D-galactofuranose
Other name(s): UGM; UDP-D-galactopyranose furanomutase
Systematic name: UDP-α-D-galactopyranose furanomutase
Comments: A flavoenzyme which generates UDP-α-D-glactofuranose required for cell wall formation in bacteria, fungi, and protozoa.
References:
1.  Trejo, A.G., Chittenden, G.J.F., Buchanan, J.G. and Baddiley, J. Uridine diphosphate α-D-galactofuranose, an intermediate in the biosynthesis of galactofuranosyl residues. Biochem. J. 117 (1970) 637–639. [PMID: 5419754]
2.  Karunan Partha, S., Bonderoff, S.A., van Straaten, K.E. and Sanders, D.A. Expression, purification and preliminary X-ray crystallographic analysis of UDP-galactopyranose mutase from Deinococcus radiodurans. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 65 (2009) 843–845. [PMID: 19652355]
3.  Dhatwalia, R., Singh, H., Oppenheimer, M., Karr, D.B., Nix, J.C., Sobrado, P. and Tanner, J.J. Crystal structures and small-angle x-ray scattering analysis of UDP-galactopyranose mutase from the pathogenic fungus Aspergillus fumigatus. J. Biol. Chem. 287 (2012) 9041–9051. [PMID: 22294687]
4.  van Straaten, K.E., Routier, F.H. and Sanders, D.A. Towards the crystal structure elucidation of eukaryotic UDP-galactopyranose mutase. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 68 (2012) 455–459. [PMID: 22505419]
[EC 5.4.99.9 created 1984, modified 2012]
 
 
EC 2.4.1.1     Relevance: 16.1%
Accepted name: glycogen phosphorylase
Reaction: [(1→4)-α-D-glucosyl]n + phosphate = [(1→4)-α-D-glucosyl]n-1 + α-D-glucose 1-phosphate
Other name(s): muscle phosphorylase a and b; amylophosphorylase; polyphosphorylase; amylopectin phosphorylase; glucan phosphorylase; α-glucan phosphorylase; 1,4-α-glucan phosphorylase; glucosan phosphorylase; granulose phosphorylase; maltodextrin phosphorylase; muscle phosphorylase; myophosphorylase; potato phosphorylase; starch phosphorylase; 1,4-α-D-glucan:phosphate α-D-glucosyltransferase; phosphorylase (ambiguous)
Systematic name: (1→4)-α-D-glucan:phosphate α-D-glucosyltransferase
Comments: This entry covers several enzymes from different sources that act in vivo on different forms of (1→4)-α-D-glucans. Some of these enzymes catalyse the first step in the degradation of large branched glycan polymers - the phosphorolytic cleavage of α-1,4-glucosidic bonds from the non-reducing ends of linear poly(1→4)-α-D-glucosyl chains within the polymers. The enzyme stops when it reaches the fourth residue away from an α-1,6 branching point, leaving a highly branched core known as a limit dextrin. The accepted name of the enzyme should be modified for each specific instance by substituting "glycogen" with the name of the natural substrate, e.g. maltodextrin phosphorylase, starch phosphorylase, etc.
References:
1.  Hanes, C.S. The breakdown and synthesis of starch by an enzyme from pea seeds. Proc. R. Soc. Lond. B Biol. Sci. 128 (1940) 421–450.
2.  Green, A.A. and Cori, G.T. Crystalline muscle phosphorylase. I. Preparation, properties, and molecular weight. J. Biol. Chem. 151 (1943) 21–29.
3.  Baum, H. and Gilbert, G.A. A simple method for the preparation of crystalline potato phosphorylase and Q-enzyme. Nature 171 (1953) 983–984. [PMID: 13063502]
4.  Cowgill, R.W. Lobster muscle phosphorylase: purfication and properties. J. Biol. Chem. 234 (1959) 3146–3153. [PMID: 13812491]
5.  Chen, G.S. and Segel, I.H. Purification and properties of glycogen phosphorylase from Escherichia coli. Arch. Biochem. Biophys. 127 (1968) 175–186. [PMID: 4878695]
6.  Fischer, E.H., Pocker, A. and Saari, J.C. The structure, function and control of glycogen phosphorylase. In: Campbell, P.N. and Greville, G.D. (Ed.), Essays in Biochemistry, vol. 6, Academic Press, London and New York, 1970, pp. 23–68.
[EC 2.4.1.1 created 1961, modified 2013]
 
 
EC 2.4.1.64     Relevance: 16.1%
Accepted name: α,α-trehalose phosphorylase
Reaction: α,α-trehalose + phosphate = D-glucose + β-D-glucose 1-phosphate
Other name(s): trehalose phosphorylase
Systematic name: α,α-trehalose:phosphate β-D-glucosyltransferase
References:
1.  Belocopitow, E. and Maréchal, L.R. Trehalose phosphorylase from Euglena gracilis. Biochim. Biophys. Acta 198 (1970) 151–154. [PMID: 5413942]
[EC 2.4.1.64 created 1972]
 
 
EC 5.3.2.3     Relevance: 16.1%
Accepted name: TDP-4-oxo-6-deoxy-α-D-glucose-3,4-oxoisomerase (dTDP-3-dehydro-6-deoxy-α-D-galactopyranose-forming)
Reaction: dTDP-4-dehydro-6-deoxy-α-D-glucopyranose = dTDP-3-dehydro-6-deoxy-α-D-galactopyranose
Other name(s): dTDP-6-deoxy-hex-4-ulose isomerase; TDP-6-deoxy-hex-4-ulose isomerase; FdtA
Systematic name: dTDP-4-dehydro-6-deoxy-α-D-glucopyranose:dTDP-3-dehydro-6-deoxy-α-D-galactopyranose isomerase
Comments: The enzyme is involved in the biosynthesis of dTDP-3-acetamido-3,6-dideoxy-α-D-galactose. Four moieties of α-D-rhamnose and two moities of 3-acetamido-3,6-dideoxy-α-D-galactose form the repeating unit of the glycan chain in the S-layer of the bacterium Aneurinibacillus thermoaerophilus.
References:
1.  Pfoestl, A., Hofinger, A., Kosma, P. and Messner, P. Biosynthesis of dTDP-3-acetamido-3,6-dideoxy-α-D-galactose in Aneurinibacillus thermoaerophilus L420-91T. J. Biol. Chem. 278 (2003) 26410–26417. [PMID: 12740380]
2.  Davis, M.L., Thoden, J.B. and Holden, H.M. The x-ray structure of dTDP-4-keto-6-deoxy-D-glucose-3,4-ketoisomerase. J. Biol. Chem. 282 (2007) 19227–19236. [PMID: 17459872]
[EC 5.3.2.3 created 2011]
 
 
EC 7.4.2.7     Relevance: 16%
Accepted name: ABC-type α-factor-pheromone transporter
Reaction: ATP + H2O + α-factor[side 1] = ADP + phosphate + α-factor[side 2]
Other name(s): α-factor-transporting ATPase; α-factor-pheromone transporting ATPase
Systematic name: ATP phosphohydrolase (ABC-type, α-factor-exporting)
Comments: An ATP-binding cassette (ABC) type transporter, characterized by the presence of two similar ATP-binding domains/proteins and two integral membrane domains/proteins. Does not undergo phosphorylation during the transport process. A yeast enzyme that exports the α-factor sex pheromone.
References:
1.  Michaelis, S. STE6, the yeast α-factor exporter. Semin. Cell Biol. 4 (1993) 17–27. [PMID: 8095825]
2.  Saier, M.H., Jr. Molecular phylogeny as a basis for the classification of transport proteins from bacteria, archaea and eukarya. Adv. Microb. Physiol. 40 (1998) 81–136. [PMID: 9889977]
[EC 7.4.2.7 created 2000 as EC 3.6.3.48, transferred 2018 to EC 7.4.2.7]
 
 
EC 3.2.1.94     Relevance: 16%
Accepted name: glucan 1,6-α-isomaltosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in polysaccharides, to remove successive isomaltose units from the non-reducing ends of the chains
Other name(s): exo-isomaltohydrolase; isomalto-dextranase; isomaltodextranase; G2-dextranase; 1,6-α-D-glucan isomaltohydrolase
Systematic name: 6-α-D-glucan isomaltohydrolase
Comments: Optimum activity is on those 1,6-α-D-glucans containing 6, 7 and 8 glucose units; those containing 3, 4 and 5 glucose units are hydrolysed at slower rates.
References:
1.  Sawai, T., Toriyama, K. and Yano, K. A bacterial dextranase releasing only isomaltose from dextrans. J. Biochem. (Tokyo) 75 (1974) 105–112. [PMID: 4826536]
2.  Sawai, T. and Niwa, Y. Transisomaltosylation activity of a bacterial isomaltodextranase. Agric. Biol. Chem. 39 (1975) 1077–1083.
[EC 3.2.1.94 created 1976]
 
 
EC 2.4.1.248     Relevance: 16%
Accepted name: cycloisomaltooligosaccharide glucanotransferase
Reaction: cyclizes part of a (1→6)-α-D-glucan chain by formation of a (1→6)-α-D-glucosidic bond
Systematic name: (1→6)-α-D-glucan:(1→6)-α-D-glucan 6-α-D-[1→6α-D-glucano]-transferase (cyclizing)
Comments: Specific for (1→6)-α-D-glucans (dextrans) and, unlike cyclomaltodextrin glucanotransferase (EC 2.4.1.19), without activity towards (1→4)-α-D-glucans, such as amylose. It also has no activity on oligosaccharides, such as amylopectin and pullulan, containing (1→6)-α-D-glucosidic linkages at branch points. The enzyme from Bacillus circulans T-3040 has been shown to form cycloisomalto-oligosaccharides of three sizes (7, 8 and 9 glucose units). It will also catalyse the disproportionation of two isomalto-oligosaccharides molecules to yield a series of isomalto-oligosachharides and the addition of D-glucose to cycloisomalto-oligosaccharides with ring opening to form isomalto-oligosaccharides.
References:
1.  Oguma T, Horiuchi, T, and Kobayashi M. Novel Cyclic dextrins, Cycloisomaltooligosaccharides, from Bacillus sp. T-3040 culture. Biosci. Biotech. Biochem. 57 (1993) 1225–1227.
2.  Oguma, T., Tobe, K. and Kobayashi, M. Purification and properties of a novel enzyme from Bacillus spp. T-3040, which catalyzes the conversion of dextran to cyclic isomaltooligosaccharides. FEBS Lett. 345 (1994) 135–138. [PMID: 7515357]
3.  Yamamoto, T., Terasawa, K., Kim, Y.M., Kimura, A., Kitamura, Y., Kobayashi, M. and Funane, K. Identification of catalytic amino acids of cyclodextran glucanotransferase from Bacillus circulans T-3040. Biosci. Biotechnol. Biochem. 70 (2006) 1947–1953. [PMID: 16926507]
[EC 2.4.1.248 created 2009]
 
 
EC 2.4.1.132     Relevance: 16%
Accepted name: GDP-Man:Man1GlcNAc2-PP-dolichol α-1,3-mannosyltransferase
Reaction: GDP-α-D-mannose + β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = GDP + α-D-Man-(1→3)-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol
Glossary: β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol = β-D-mannosyl-(1→4)-N,N′-diacetylchitobiosyldiphosphodolichol
Other name(s): Alg2 mannosyltransferase (ambiguous); ALG2 (gene name, ambiguous); glycolipid 3-α-mannosyltransferase; GDP-mannose:glycolipid 3-α-D-mannosyltransferase; GDP-Man:Man1GlcNAc2-PP-Dol α-1,3-mannosyltransferase; GDP-D-mannose:D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol 3-α-mannosyltransferase
Systematic name: GDP-α-D-mannose:β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-α-D-GlcNAc-diphosphodolichol 3-α-D-mannosyltransferase (configuration-retaining)
Comments: The biosynthesis of asparagine-linked glycoproteins utilizes a dolichyl diphosphate-linked glycosyl donor, which is assembled by the series of membrane-bound glycosyltransferases that comprise the dolichol pathway. Alg2 mannosyltransferase from Saccharomyces cerevisiae carries out an α1,3-mannosylation of D-Man-β-(1→4)-D-GlcNAc-β-(1→4)-D-GlcNAc-diphosphodolichol, followed by an α1,6-mannosylation (cf. EC 2.4.1.257), to form the first branched pentasaccharide intermediate of the dolichol pathway [1,2].
References:
1.  Kampf, M., Absmanner, B., Schwarz, M. and Lehle, L. Biochemical characterization and membrane topology of Alg2 from Saccharomyces cerevisiae as a bifunctional α1,3- and 1,6-mannosyltransferase involved in lipid-linked oligosaccharide biosynthesis. J. Biol. Chem. 284 (2009) 11900–11912. [PMID: 19282279]
2.  O'Reilly, M.K., Zhang, G. and Imperiali, B. In vitro evidence for the dual function of Alg2 and Alg11: essential mannosyltransferases in N-linked glycoprotein biosynthesis. Biochemistry 45 (2006) 9593–9603. [PMID: 16878994]
[EC 2.4.1.132 created 1984, modified 2011, modified 2012]
 
 
EC 3.2.1.174     Relevance: 15.9%
Accepted name: rhamnogalacturonan rhamnohydrolase
Reaction: Exohydrolysis of the α-L-Rha-(1→4)-α-D-GalA bond in rhamnogalacturonan oligosaccharides with initial inversion of configuration releasing β-L-rhamnose from the non-reducing end of rhamnogalacturonan oligosaccharides.
Other name(s): RG-rhamnohydrolase; RG α-L-rhamnopyranohydrolase
Systematic name: rhamnogalacturonan oligosaccharide α-L-Rha-(1→4)-α-D-GalA rhamnohydrolase
Comments: The enzyme is part of the degradation system for rhamnogalacturonan I in Aspergillus aculeatus.
References:
1.  Pitson, S.M., Mutter, M., van den Broek, L.A., Voragen, A.G. and Beldman, G. Stereochemical course of hydrolysis catalysed by α-L-rhamnosyl and α-D-galacturonosyl hydrolases from Aspergillus aculeatus. Biochem. Biophys. Res. Commun. 242 (1998) 552–559. [PMID: 9464254]
2.  Mutter, M., Beldman, G., Schols, H.A. and Voragen, A.G. Rhamnogalacturonan α-L-rhamnopyranohydrolase. A novel enzyme specific for the terminal nonreducing rhamnosyl unit in rhamnogalacturonan regions of pectin. Plant Physiol. 106 (1994) 241–250. [PMID: 7972516]
[EC 3.2.1.174 created 2011]
 
 
EC 3.2.1.76     Relevance: 15.9%
Accepted name: L-iduronidase
Reaction: Hydrolysis of unsulfated α-L-iduronosidic linkages in dermatan sulfate
Other name(s): α-L-iduronidase
Systematic name: glycosaminoglycan α-L-iduronohydrolase
References:
1.  Matalon, R., Cifonelli, J.A. and Dorfman, A. L-Iduronidase in cultured human fibroblasts and liver. Biochem. Biophys. Res. Commun. 42 (1971) 340–345. [PMID: 4993544]
2.  Rome, L.H., Garvin, A.J. and Neufeld, E.F. Human kidney α-L-iduronidase: purification and characterization. Arch. Biochem. Biophys. 189 (1978) 344–353. [PMID: 30407]
3.  Srivastava, R.M., Hudson, N., Seymour, F.R. and Weissman, B. Preparation of (aryl α-L-idopyranosid)uronic acids. Carbohydr. Res. 60 (1978) 315–326.
[EC 3.2.1.76 created 1972]
 
 
EC 2.4.1.352     Relevance: 15.9%
Accepted name: glucosylglycerate phosphorylase
Reaction: 2-O-(α-D-glucopyranosyl)-D-glycerate + phosphate = α-D-glucopyranose 1-phosphate + D-glycerate
Systematic name: 2-O-(α-D-glucopyranosyl)-D-glycerate:phosphate α-D-glucosyltransferase (configuration-retaining)
Comments: The enzyme has been characterized from the bacterium Meiothermus silvanus.
References:
1.  Franceus, J., Pinel, D. and Desmet, T. Glucosylglycerate phosphorylase, an enzyme with novel specificity involved in compatible solute metabolism. Appl. Environ. Microbiol. 83 (2017) . [PMID: 28754708]
[EC 2.4.1.352 created 2018]
 
 
EC 3.2.1.3     Relevance: 15.9%
Accepted name: glucan 1,4-α-glucosidase
Reaction: Hydrolysis of terminal (1→4)-linked α-D-glucose residues successively from non-reducing ends of the chains with release of β-D-glucose
Other name(s): glucoamylase; amyloglucosidase; γ-amylase; lysosomal α-glucosidase; acid maltase; exo-1,4-α-glucosidase; glucose amylase; γ-1,4-glucan glucohydrolase; acid maltase; 1,4-α-D-glucan glucohydrolase
Systematic name: 4-α-D-glucan glucohydrolase
Comments: Most forms of the enzyme can rapidly hydrolyse 1,6-α-D-glucosidic bonds when the next bond in the sequence is 1,4, and some preparations of this enzyme hydrolyse 1,6- and 1,3-α-D-glucosidic bonds in other polysaccharides. This entry covers all such enzymes acting on polysaccharides more rapidly than on oligosaccharides. EC 3.2.1.20 α-glucosidase, from mammalian intestine, can catalyse similar reactions.
References:
1.  French, D. and Knapp, D.W. The maltase of Clostridium acetobutylicum. J. Biol. Chem. 187 (1950) 463–471. [PMID: 14803428]
2.  Illingworth Brown, B. and Brown, D.H. The subcellular distribution of enzymes in type II glycogenosis and the occurrence of an oligo-α-1,4-glucan glucohydrolase in human tissues. Biochim. Biophys. Acta 110 (1965) 124–133. [PMID: 4286143]
3.  Jeffrey, P.L., Brown, D.H. and Brown, B.I. Studies of lysosomal α-glucosidase. I. Purification and properties of the rat liver enzyme. Biochemistry 9 (1970) 1403–1415. [PMID: 4313883]
4.  Kelly, J.J. and Alpers, D.H. Properties of human intestinal glucoamylase. Biochim. Biophys. Acta 315 (1973) 113–122. [PMID: 4743896]
5.  Miller, K.D. and Copeland, W.H. A blood trans-α-glucosylase. Biochim. Biophys. Acta 22 (1956) 193–194. [PMID: 13373867]
6.  Tsujisaka, Y., Fukimoto, J. and Yamamoto, T. Specificity of crystalline saccharogenic amylase of moulds. Nature 181 (1958) 770–771. [PMID: 13517301]
[EC 3.2.1.3 created 1961]
 
 
EC 3.1.1.119      
Transferred entry: exo-acting protein-α-N-acetylgalactosaminidase. The enzyme was discovered at the public-review stage to have been misclassified and so was withdrawn. See EC 3.2.1.217, exo-acting protein-α-N-acetylgalactosaminidase.
[EC 3.1.1.119 created 2022, deleted 2022]
 
 
EC 3.2.1.217     Relevance: 15.9%
Accepted name: exo-acting protein-α-N-acetylgalactosaminidase
Reaction: a [protein]-N-acetyl-α-D-galactosalaminyl-(L-serine/L-threonine) + H2O = a [protein]-(L-serine/L-threonine) + N-acetyl-D-galactosamine
Other name(s): Nag31
Systematic name: [protein]-N-acetyl-α-D-galactosalaminyl-(L-serine/L-threonine) N-acetylgalactosaminohydrolase
Comments: The enzyme, which belongs to the glycosylhydrolase 31 (GH31) family, is an exo-acting α-N-acetylgalactosaminidase that acts on the innermost α-GalNAc residues at the core of O-glycans when no other saccharides are attached to it. Unlike EC 3.2.1.49, α-N-acetylgalactosaminidase, it is not able to act on blood group A antigen.
References:
1.  Rahfeld, P., Wardman, J.F., Mehr, K., Huff, D., Morgan-Lang, C., Chen, H.M., Hallam, S.J. and Withers, S.G. Prospecting for microbial α-N-acetylgalactosaminidases yields a new class of GH31 O-glycanase. J. Biol. Chem. 294 (2019) 16400–16415. [PMID: 31530641]
2.  Miyazaki, T. and Park, E.Y. Crystal structure of the Enterococcus faecalis α-N-acetylgalactosaminidase, a member of the glycoside hydrolase family 31. FEBS Lett. 594 (2020) 2282–2293. [PMID: 32367553]
3.  Ikegaya, M., Miyazaki, T. and Park, E.Y. Biochemical characterization of Bombyx mori α-N-acetylgalactosaminidase belonging to the glycoside hydrolase family 31. Insect Mol Biol 30 (2021) 367–378. [PMID: 33742736]
4.  Miyazaki, T., Ikegaya, M. and Alonso-Gil, S. Structural and mechanistic insights into the substrate specificity and hydrolysis of GH31 α-N-acetylgalactosaminidase. Biochimie (2021) . [PMID: 34826537]
[EC 3.2.1.217 created 2022]
 
 
EC 3.2.1.142     Relevance: 15.9%
Accepted name: limit dextrinase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in α- and β-limit dextrins of amylopectin and glycogen, and in amylopectin and pullulan
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Other name(s): R-enzyme; amylopectin-1,6-glucosidase; dextrin α-1,6-glucanohydrolase
Systematic name: dextrin 6-α-glucanohydrolase
Comments: Plant enzymes with little or no action on glycogen. Action on amylopectin is incomplete, but action on α-limit dextrins is complete. Maltose is the smallest sugar it can release from an α-(1→6)-linkage.
References:
1.  Gordon, R.W., Manners, D.J. and Stark, J.R. The limit dextrinase of the broad bean (Vicia faba). Carbohydr. Res. 42 (1975) 125–134.
2.  Manners, D.J. Observations on the specificity and nomenclature of starch debranching enzymes. J. Appl. Glycosci. 44 (1997) 83–85.
[EC 3.2.1.142 created 2000]
 
 
EC 3.1.3.70     Relevance: 15.8%
Accepted name: mannosyl-3-phosphoglycerate phosphatase
Reaction: 2-O-(α-D-mannosyl)-3-phosphoglycerate + H2O = 2-O-(α-D-mannosyl)-D-glycerate + phosphate
Systematic name: 2-O-(α-D-mannosyl)-3-phosphoglycerate phosphohydrolase
Comments: Requires Mg2+. The enzyme from Pyrococcus horikoshii is specific for α-D-mannosyl-3-phosphoglycerate and forms part of the pathway for the synthesis of mannosylglycerate.
References:
1.  Empadinhas, N., Marugg, J.D., Borges, N., Santos, H. and da Costa, M.S. Pathway for the synthesis of mannosylglycerate in the hyperthermophilic archaeon Pyrococcus horikoshii. Biochemical and genetic characterization of key-enzymes. J. Biol. Chem. 276 (2001) 43580–43588. [PMID: 11562374]
[EC 3.1.3.70 created 2002]
 
 
EC 2.4.1.284     Relevance: 15.8%
Accepted name: 2-deoxystreptamine glucosyltransferase
Reaction: UDP-α-D-glucose + 2-deoxystreptamine = UDP + 2′-deamino-2′-hydroxyparomamine
Glossary: 2′-deamino-2′-hydroxyparomamine = 4-O-α-D-glucopyranosyl-2-deoxy-D-streptamine
Other name(s): kanF (gene name)
Systematic name: UDP-α-D-glucose:2-deoxystreptamine 6-α-D-glucosyltransferase
Comments: Involved in the biosynthesis of kanamycin B and kanamycin C. Also catalyses EC 2.4.1.283, 2-deoxystreptamine N-acetyl-D-glucosaminyltransferase, but activity is only one fifth of that with UDP-α-D-glucose.
References:
1.  Park, J.W., Park, S.R., Nepal, K.K., Han, A.R., Ban, Y.H., Yoo, Y.J., Kim, E.J., Kim, E.M., Kim, D., Sohng, J.K. and Yoon, Y.J. Discovery of parallel pathways of kanamycin biosynthesis allows antibiotic manipulation. Nat. Chem. Biol. 7 (2011) 843–852. [PMID: 21983602]
[EC 2.4.1.284 created 2012]
 
 
EC 2.7.7.99     Relevance: 15.8%
Accepted name: N-acetyl-α-D-muramate 1-phosphate uridylyltransferase
Reaction: UDP + N-acetyl-α-D-muramate 1-phosphate = UDP-N-acetyl-α-D-muramate + phosphate
Glossary: N-acetyl-α-D-muramate = 3-O-[(1R)-1-carboxyethyl]-2-acetoxy-2-deoxy-D-glucopyranose
Other name(s): murU (gene name)
Systematic name: UDP:N-acetyl-α-D-muramate 1-phosphate uridylyltransferase
Comments: The enzyme, characterized from Pseudomonas species, participates in a peptidoglycan salvage pathway.
References:
1.  Gisin, J., Schneider, A., Nagele, B., Borisova, M. and Mayer, C. A cell wall recycling shortcut that bypasses peptidoglycan de novo biosynthesis. Nat. Chem. Biol. 9 (2013) 491–493. [PMID: 23831760]
2.  Renner-Schneck, M., Hinderberger, I., Gisin, J., Exner, T., Mayer, C. and Stehle, T. Crystal structure of the N-acetylmuramic acid α-1-phosphate (MurNAc-α1-P) uridylyltransferase MurU, a minimal sugar nucleotidyltransferase and potential drug target enzyme in Gram-negative pathogens. J. Biol. Chem. 290 (2015) 10804–10813. [PMID: 25767118]
[EC 2.7.7.99 created 2017]
 
 
EC 3.2.1.144     Relevance: 15.8%
Accepted name: 3-deoxyoctulosonase
Reaction: 3-deoxyoctulosonyl-lipopolysaccharide + H2O = 3-deoxyoctulosonic acid + lipopolysaccharide
Other name(s): α-Kdo-ase
Systematic name: 3-deoxyoctulosonyl-lipopolysaccharide hydrolase
Comments: Releases Kdo (α- and β-linked 3-deoxy-D-manno-octulosonic acid) from different lipopolysaccharides, including Re-LPS from Escherichia coli and Salmonella, Rd-LPS from S. minnesota, and de-O-acyl-re-LPS. 4-Methylumbelliferyl-α-Kdo (α-Kdo-OMec) is also a substrate.
References:
1.  Li, Y.T., Wang, L.X., Pavlova, N.V., Li, S.C. and Lee, Y.C. α-KDOase activity in oyster and synthesis of α- and β-4-methylumbelliferyl ketosides of 3-deoxy-D-manno-octulosonic acid (KDO). J. Biol. Chem. 272 (1997) 26419–26424. [PMID: 9334217]
[EC 3.2.1.144 created 2000]
 
 
EC 2.7.1.6     Relevance: 15.8%
Accepted name: galactokinase
Reaction: ATP + α-D-galactose = ADP + α-D-galactose 1-phosphate
Other name(s): galactokinase (phosphorylating); ATP:D-galactose-1-phosphotransferase
Systematic name: ATP:α-D-galactose 1-phosphotransferase
Comments: Part of the Leloir pathway for galactose metabolism. The enzymes from mammals and from the bacterium Escherichia coli have no activity with N-acetyl-α-D-galactosamine [4-6].
References:
1.  Cardini, C.E. and Leloir, L.F. Enzymic phosphorylation of galactosamine and galactose. Arch. Biochem. Biophys. 45 (1953) 55–64. [PMID: 13058412]
2.  Neufeld, E.F., Feingold, D.S. and Hassid, W.Z. Phosphorylation of D-galactose and L-arabinose by extracts from Phaseolus aureus seedlings. J. Biol. Chem. 235 (1960) 906–909. [PMID: 14426659]
3.  Wilkinson, J.F. The pathway of the adaptive fermentation of galactose by yeast. Biochem. J. 44 (1949) 460–467. [PMID: 16748546]
4.  Yang, J., Fu, X., Jia, Q., Shen, J., Biggins, J.B., Jiang, J., Zhao, J., Schmidt, J.J., Wang, P.G. and Thorson, J.S. Studies on the substrate specificity of Escherichia coli galactokinase. Org. Lett. 5 (2003) 2223–2226. [PMID: 12816414]
5.  Timson, D.J. and Reece, R.J. Sugar recognition by human galactokinase. BMC Biochem. 4:16 (2003). [PMID: 14596685]
6.  Thoden, J.B., Timson, D.J., Reece, R.J. and Holden, H.M. Molecular structure of human galactokinase: implications for type II galactosemia. J. Biol. Chem. 280 (2005) 9662–9670. [PMID: 15590630]
[EC 2.7.1.6 created 1961]
 
 
EC 4.2.2.13     Relevance: 15.8%
Accepted name: exo-(1→4)-α-D-glucan lyase
Reaction: linear α-glucan = (n-1) 1,5-anhydro-D-fructose + D-glucose
Other name(s): α-(1→4)-glucan 1,5-anhydro-D-fructose eliminase; α-1,4-glucan exo-lyase; α-1,4-glucan lyase; GLase
Systematic name: (1→4)-α-D-glucan exo-4-lyase (1,5-anhydro-D-fructose-forming)
Comments: The enzyme catalyses the sequential degradation of (1→4)-α-D-glucans from the non-reducing end with the release of 1,5-anhydro-D-fructose. Thus, for an α-glucan containing n (1→4)-linked glucose units, the final products are 1 glucose plus (n-1) 1,5-anhydro-D-fructose. Maltose, maltosaccharides and amylose are all completely degraded. It does not degrade (1→6)-α-glucosidic bonds and thus the degradation of a branched glucan, such as amylopectin or glycogen, will result in the formation of 1,5-anhydro-D-fructose plus a limit dextrin. Other enzymes involved in the anhydrofructose pathway are EC 4.2.1.110 (aldos-2-ulose dehydratase), EC 4.2.1.111 (1,5-anhydro-D-fructose dehydratase) and EC 5.3.2.7 (ascopyrone tautomerase).
References:
1.  Yu, S., Kenne, L., Pedersén, M. α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. I. Efficient purification and characterization from red seaweeds. Biochim. Biophys. Acta 1156 (1993) 313–320. [PMID: 8461323]
2.  Yu, S., Pedersén, M. α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. II. Subcellular localization and partial amino-acid sequence. Planta 191 (1993) 137–142. [PMID: 7763826]
3.  Yu, S., Ahmad, T., Kenne, L. and Pedersén, M. α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. III. Substrate specificity, mode of action, and cleavage mechanism. Biochim. Biophys. Acta 1244 (1995) 1–9. [PMID: 7766642]
4.  Yu, S., Christensen, T.M., Kragh, K.M., Bojsen, K. and Marcussen, J. Efficient purification, characterization and partial amino acid sequencing of two α-1,4-glucan lyases from fungi. Biochim. Biophys. Acta 1339 (1997) 311–320. [PMID: 9187252]
5.  Yu, S., Bojsen, K., Svensson, B. and Marcussen, J. α-1,4-glucan lyases producing 1,5-anhydro-D-fructose from starch and glycogen have sequence similarity to α-glucosidases. Biochim. Biophys. Acta 1433 (1999) 1–15. [PMID: 10446355]
6.  Lee, S.S., Yu, S. and Withers, S.G. α-1,4-Glucan lyase performs a trans-elimination via a nucleophilic displacement followed by a syn-elimination. J. Am. Chem. Soc. 124 (2002) 4948–4949. [PMID: 11982345]
7.  Lee, S.S., Yu, S. and Withers, S.G. Detailed dissection of a new mechanism for glycoside cleavage: α-1,4-glucan lyase. Biochemistry 42 (2003) 13081–13090. [PMID: 14596624]
[EC 4.2.2.13 created 1999]
 
 
EC 5.4.2.7     Relevance: 15.8%
Accepted name: phosphopentomutase
Reaction: α-D-ribose 1-phosphate = D-ribose 5-phosphate
Other name(s): phosphodeoxyribomutase; deoxyribose phosphomutase; deoxyribomutase; phosphoribomutase; α-D-glucose-1,6-bisphosphate:deoxy-D-ribose-1-phosphate phosphotransferase; D-ribose 1,5-phosphomutase
Systematic name: α-D-ribose 1,5-phosphomutase
Comments: Also converts 2-deoxy-α-D-ribose 1-phosphate into 2-deoxy-D-ribose 5-phosphate. α-D-Ribose 1,5-bisphosphate, 2-deoxy-α-D-ribose 1,5-bisphosphate, or α-D-glucose 1,6-bisphosphate can act as cofactor.
References:
1.  Hammen-Jepersen, K. and Munch-Petersen, A. Phosphodeoxyribomutase from Escherichia coli. Purification and some properties. Eur. J. Biochem. 17 (1970) 397–407. [PMID: 4992818]
2.  Kammen, H.O. and Koo, R. Phosphopentomutases. I. Identification of two activities in rabbit tissues. J. Biol. Chem. 244 (1969) 4888–4893. [PMID: 5824563]
3.  Ray, W.J., Jr. and Peck, E.J., Jr. Phosphomutases. In: Boyer, P.D. (Ed.), The Enzymes, 3rd edn, vol. 6, 1972, pp. 407–477.
[EC 5.4.2.7 created 1972 as EC 2.7.5.6, transferred 1984 to EC 5.4.2.7]
 
 
EC 5.1.3.10     Relevance: 15.7%
Accepted name: CDP-paratose 2-epimerase
Reaction: CDP-α-D-paratose = CDP-α-D-tyvelose
Glossary: CDP-α-D-tyvelose = CDP-3,6-dideoxy-α-D-mannose = CDP-3,6-dideoxy-α-D-arabino-hexose
CDP-α-D-paratose = CDP-3,6-dideoxy-α-D-glucose = CDP-3,6-dideoxy-α-D-ribo-hexose
Other name(s): CDP-paratose epimerase; cytidine diphosphoabequose epimerase; cytidine diphosphodideoxyglucose epimerase; cytidine diphosphoparatose epimerase; cytidine diphosphate paratose-2-epimerase; CDP-abequose epimerase (incorrect); CDP-D-abequose 2-epimerase (incorrect); CDP-tyvelose 2-epimerase,
Systematic name: CDP-3,6-dideoxy-D-glucose 2-epimerase
Comments: Requires NAD+.
References:
1.  Matsuhashi, S. Enzymatic synthesis of cytidine diphosphate 3,6-dideoxyhexoses. II. Reversible 2-epimerization of cytidine diphosphate paratose. J. Biol. Chem. 241 (1966) 4275–4282. [PMID: 5924649]
2.  Liu, H.-W. and Thorson, J.S. Pathways and mechanisms in the biogenesis of novel deoxysugars by bacteria. Annu. Rev. Microbiol. 48 (1994) 223–256. [PMID: 7826006]
3.  Koropatkin, N.M., Liu, H.W. and Holden, H.M. High resolution x-ray structure of tyvelose epimerase from Salmonella typhi. J. Biol. Chem. 278 (2003) 20874–20881. [PMID: 12642575]
[EC 5.1.3.10 created 1972, modified 2005]
 
 
EC 3.2.1.33     Relevance: 15.7%
Accepted name: amylo-α-1,6-glucosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic branch linkages in glycogen phosphorylase limit dextrin
Other name(s): amylo-1,6-glucosidase; dextrin 6-α-D-glucosidase; amylopectin 1,6-glucosidase; dextrin-1,6-glucosidase; glycogen phosphorylase-limit dextrin α-1,6-glucohydrolase
Systematic name: glycogen phosphorylase-limit dextrin 6-α-glucohydrolase
Comments: This enzyme hydrolyses an unsubstituted glucose unit linked by an α(1→6) bond to an α(1→4) glucose chain. The enzyme activity found in mammals and yeast is in a polypeptide chain containing two active centres. The other activity is similar to that of EC 2.4.1.25 (4-α-glucanotransferase), which acts on the glycogen phosphorylase limit dextrin chains to expose the single glucose residues, which the 6-α-glucosidase activity can then hydrolyse. Together, these two activities constitute the glycogen debranching system.
References:
1.  Brown, D.H. and Brown, B.I. Enzymes of glycogen debranching: Amylo-1,6-glucosidase (I) and oligo-1,4→1,4-glucanotransferase (II). Methods Enzymol. 8 (1966) 515–524.
2.  Lee, E.Y.C., Carter, J.H., Nielsen, L.D. and Fischer, E.H. Purification and properties of yeast amylo-1,6-glucosidase-oligo-1,4 leads to 1,4-glucantransferase. Biochemistry 9 (1970) 2347–2355. [PMID: 5424210]
3.  Nelson, T.E., Kolb, E. and Larner, J. Purification and properties of rabbit muscle amylo-1,6-glucosidase-oligo-1,4-1,4-transferase. Biochemistry 8 (1969) 1419–1428. [PMID: 5805288]
[EC 3.2.1.33 created 1965, modified 2000]
 
 
EC 3.2.1.15     Relevance: 15.7%
Accepted name: endo-polygalacturonase
Reaction: (1,4-α-D-galacturonosyl)n+m + H2O = (1,4-α-D-galacturonosyl)n + (1,4-α-D-galacturonosyl)m
Other name(s): pectin depolymerase (ambiguous); pectinase (ambiguous); endopolygalacturonase; pectolase (ambiguous); pectin hydrolase (ambiguous); pectin polygalacturonase (ambiguous); polygalacturonase (ambiguous); poly-α-1,4-galacturonide glycanohydrolase (ambiguous); endogalacturonase; endo-D-galacturonase; poly(1,4-α-D-galacturonide) glycanohydrolase (ambiguous)
Systematic name: (1→4)-α-D-galacturonan glycanohydrolase (endo-cleaving)
Comments: The enzyme catalyses the random hydrolysis of (1→4)-α-D-galactosiduronic linkages in pectate and other galacturonans. Different forms of the enzyme have different tolerances to methyl esterification of the substrate.
References:
1.  Lineweaver, H. and Jansen, E.F. Pectic enzymes. Adv. Enzymol. Relat. Subj. Biochem. 11 (1951) 267–295.
2.  McCready, R.M. and Seegmiller, C.G. Action of pectic enzymes on oligogalacturonic acids and some of their derivatives. Arch. Biochem. Biophys. 50 (1954) 440–450. [PMID: 13159344]
3.  Phaff, H.J. and Demain, A.L. The unienzymatic nature of yeast polygalacturonase. J. Biol. Chem. 218 (1956) 875–884. [PMID: 13295238]
4.  Deuel, H. and Stutz, E. Pectic substances and pectic enzymes. Adv. Enzymol. Relat. Areas Mol. Biol. 20 (1958) 341–382. [PMID: 13605988]
5.  Mill, P.J. and Tuttobello, R. The pectic enzymes of Aspergillus niger. 2. Endopolygalacturonase. Biochem. J. 79 (1961) 57–64. [PMID: 13770689]
[EC 3.2.1.15 created 1961, modified 2019]
 
 
EC 2.4.1.351     Relevance: 15.7%
Accepted name: rhamnogalacturonan I rhamnosyltransferase
Reaction: UDP-β-L-rhamnose + α-D-galacturonosyl-[(1→2)-α-L-rhamnosyl-(1→4)-α-D-galacturonosyl]n = UDP + [(1→2)-α-L-rhamnosyl-(1→4)-α-D-galacturonosyl]n+1
Other name(s): RRT; RG I rhamnosyltransferase
Systematic name: UDP-β-L-rhamnose:rhamnogalacturonan I 4-rhamnosyltransferase (configuration-inverting)
Comments: The enzyme, characterized from Vigna angularis (azuki beans), participates in the biosynthesis of rhamnogalacturonan type I. It does not require any metal ions, and prefers substrates with a degree of polymerization larger than 7.
References:
1.  Uehara, Y., Tamura, S., Maki, Y., Yagyu, K., Mizoguchi, T., Tamiaki, H., Imai, T., Ishii, T., Ohashi, T., Fujiyama, K. and Ishimizu, T. Biochemical characterization of rhamnosyltransferase involved in biosynthesis of pectic rhamnogalacturonan I in plant cell wall. Biochem. Biophys. Res. Commun. 486 (2017) 130–136. [PMID: 28283389]
[EC 2.4.1.351 created 2018]
 
 
EC 3.1.3.85     Relevance: 15.7%
Accepted name: glucosyl-3-phosphoglycerate phosphatase
Reaction: 2-O-(α-D-glucopyranosyl)-3-phospho-D-glycerate + H2O = 2-O-(α-D-glucopyranosyl)-D-glycerate + phosphate
Other name(s): GpgP protein
Systematic name: α-D-glucosyl-3-phospho-D-glycerate phosphohydrolase
Comments: The enzyme is involved in biosynthesis of 2-O-(α-D-glucopyranosyl)-D-glycerate via the two-step pathway in which EC 2.4.1.266 (glucosyl-3-phosphoglycerate synthase) catalyses the conversion of GDP-glucose and 3-phospho-D-glycerate into 2-O-(α-D-glucopyranosyl)-3-phospho-D-glycerate, which is then converted to 2-O-(α-D-glucopyranosyl)-D-glycerate by glucosyl-3-phosphoglycerate phosphatase. In vivo the enzyme catalyses the dephosphorylation of 2-O-(α-D-mannopyranosyl)-3-phospho-D-glycerate with lower efficiency [1,2]. Divalent metal ions (Mg2+, Mn2+ or Co2+) stimulate activity [1,2].
References:
1.  Costa, J., Empadinhas, N. and da Costa, M.S. Glucosylglycerate biosynthesis in the deepest lineage of the bacteria: characterization of the thermophilic proteins GpgS and GpgP from Persephonella marina. J. Bacteriol. 189 (2007) 1648–1654. [PMID: 17189358]
2.  Costa, J., Empadinhas, N., Goncalves, L., Lamosa, P., Santos, H. and da Costa, M.S. Characterization of the biosynthetic pathway of glucosylglycerate in the archaeon Methanococcoides burtonii. J. Bacteriol. 188 (2006) 1022–1030. [PMID: 16428406]
3.  Mendes, V., Maranha, A., Alarico, S., da Costa, M.S. and Empadinhas, N. Mycobacterium tuberculosis Rv2419c, the missing glucosyl-3-phosphoglycerate phosphatase for the second step in methylglucose lipopolysaccharide biosynthesis. Sci. Rep. 1:177 (2011). [PMID: 22355692]
[EC 3.1.3.85 created 2011]
 
 
EC 1.1.1.342     Relevance: 15.7%
Accepted name: CDP-paratose synthase
Reaction: CDP-α-D-paratose + NADP+ = CDP-4-dehydro-3,6-dideoxy-α-D-glucose + NADPH + H+
Glossary: CDP-α-D-paratose = CDP-3,6-dideoxy-α-D-glucose = CDP-3,6-dideoxy-α-D-ribo-hexose
Other name(s): rfbS (gene name)
Systematic name: CDP-α-D-paratose:NADP+ 4-oxidoreductase
Comments: The enzyme is involved in synthesis of paratose and tyvelose, unusual 3,6-dideoxyhexose sugars that form part of the O-antigen in the lipopolysaccharides of several enteric bacteria. Isolated from Salmonella enterica subsp. enterica serovar Typhi (Salmonella typhi).
References:
1.  Verma, N. and Reeves, P. Identification and sequence of rfbS and rfbE, which determine antigenic specificity of group A and group D salmonellae. J. Bacteriol. 171 (1989) 5694–5701. [PMID: 2793833]
2.  Hallis, T.M., Lei, Y., Que, N.L. and Liu, H. Mechanistic studies of the biosynthesis of paratose: purification and characterization of CDP-paratose synthase. Biochemistry 37 (1998) 4935–4945. [PMID: 9538012]
[EC 1.1.1.342 created 2012]
 
 
EC 2.4.1.143     Relevance: 15.6%
Accepted name: α-1,6-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein] = UDP + β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein]
Other name(s): MGAT2 (gene name); N-acetylglucosaminyltransferase II; N-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase II; acetylglucosaminyltransferase II; uridine diphosphoacetylglucosamine-mannoside α1→6-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-α-1,6-mannosylglycoprotein β-1-2-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-α-D-mannoside β1-2-acetylglucosaminyltransferase; UDP-GlcNAc:mannoside α1-6 acetylglucosaminyltransferase; α-1,6-mannosyl-glycoprotein β-1,2-N-acetylglucosaminyltransferase; GnTII; GlcNAc-T II; UDP-N-acetyl-D-glucosamine:6-(α-D-mannosyl)-β-D-mannosyl-glycoprotein 2-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:α-D-mannosyl-(1→6)-β-D-mannosyl-glycoprotein 2-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: The enzyme, found in plants and animals, participates in the processing of N-glycans in the Golgi apparatus. Its activity initiates the synthesis of the second antenna of di-antennary complex N-glycans. While the natural substrate (produced by EC 3.2.1.114, mannosyl-oligosaccharide 1,3-1,6-α-mannosidase) is described here, the minimal substrate recognized by the enzyme is α-D-Man-(1→6)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→3)]-β-D-Man-R.
References:
1.  Harpaz, N. and Schachter, H. Control of glycoprotein synthesis. Bovine colostrum UDP-N-acetylglucosamine:α-D-mannoside β2-N-acetylglucosaminyltransferase I. Separation from UDP-N-acetylglucosamine:α-D-mannoside β2-N-acetylglucosaminyltransferase II, partial purification, and substrate specificity. J. Biol. Chem. 255 (1980) 4885–4893. [PMID: 6445358]
2.  Mendicino, J., Chandrasekaran, E.V., Anumula, K.R. and Davila, M. Isolation and properties of α-D-mannose:β-1,2-N-acetylglucosaminyltransferase from trachea mucosa. Biochemistry 20 (1981) 967–976. [PMID: 6452163]
3.  Oppenheimer, C.L., Eckhardt, A.E. and Hill, R.L. The nonidentity of porcine N-acetylglucosaminyltransferases I and II. J. Biol. Chem. 256 (1981) 11477–11482. [PMID: 6457827]
4.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
5.  Bendiak, B. and Schachter, H. Control of glycoprotein synthesis. Kinetic mechanism, substrate specificity, and inhibition characteristics of UDP-N-acetylglucosamine:α-D-mannoside β-1-2 N-acetylglucosaminyltransferase II from rat liver. J. Biol. Chem. 262 (1987) 5784–5790. [PMID: 2952645]
6.  Bendiak, B. and Schacter, H. Control of glycoprotein synthesis. Purification of UDP-N-acetylglucosamine:α-D-mannoside β1-2 N-acetylglucosaminyltransferase II from rat liver. J. Biol. Chem. 262 (1987) 5775–5783. [PMID: 2952644]
7.  Tan, J., D'Agostaro, A.F., Bendiak, B., Reck, F., Sarkar, M., Squire, J.A., Leong, P. and Schachter, H. The human UDP-N-acetylglucosamine: α-6-D-mannoside-β-1,2- N-acetylglucosaminyltransferase II gene (MGAT2). Cloning of genomic DNA, localization to chromosome 14q21, expression in insect cells and purification of the recombinant protein. Eur. J. Biochem. 231 (1995) 317–328. [PMID: 7635144]
[EC 2.4.1.143 created 1984, modified 2001 (EC 2.4.1.51 created 1972, part incorporated 1984), modified 2018]
 
 
EC 1.2.1.92     Relevance: 15.6%
Accepted name: 3,6-anhydro-α-L-galactose dehydrogenase
Reaction: 3,6-anhydro-α-L-galactopyranose + NAD(P)+ + H2O = 3,6-anhydro-L-galactonate + NAD(P)H + H+
Systematic name: 3,6-anhydro-α-L-galactopyranose:NAD(P)+ 1-oxidoredutase
Comments: The enzyme, characterized from the marine bacterium Vibrio sp. EJY3, is involved in a degradation pathway for 3,6-anhydro-α-L-galactose, a major component of the polysaccharides produced by red macroalgae, such as agarose and porphyran.
References:
1.  Yun, E.J., Lee, S., Kim, H.T., Pelton, J.G., Kim, S., Ko H,-J., Choi I,-G. and Kim, K.H. The novel catabolic pathway of 3,6-anhydro-L-galactose, the main component of red macroalgae, in a marine bacterium. Environ. Microbiol. 17 (2014) 1677–1688. [PMID: 25156229]
[EC 1.2.1.92 created 2014]
 
 
EC 2.4.1.65     Relevance: 15.6%
Accepted name: 3-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = GDP + β-D-galactosyl-(1→3)-[α-L-fucosyl-(1→4)]-N-acetyl-β-D-glucosaminyl-R
Other name(s): (Lea)-dependent (α-3/4)-fucosyltransferase; α(1,3/1,4) fucosyltransferase III; α-(1→4)-L-fucosyltransferase; α-4-L-fucosyltransferase; β-acetylglucosaminylsaccharide fucosyltransferase; FucT-II; Lewis α-(1→3/4)-fucosyltransferase; Lewis blood group α-(1→3/4)-fucosyltransferase; Lewis(Le) blood group gene-dependent α-(1→3/4)-L-fucosyltransferase; blood group Lewis α-4-fucosyltransferase; blood-group substance Lea-dependent fucosyltransferase; guanosine diphosphofucose-β-acetylglucosaminylsaccharide 4-α-L-fucosyltransferase; guanosine diphosphofucose-glycoprotein 4-α-L-fucosyltransferase; guanosine diphosphofucose-glycoprotein 4-α-fucosyltransferase; 3-α-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase; GDP-β-L-fucose:3-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 4I-α-L-fucosyltransferase; GDP-L-fucose:3-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 4I-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R 4I-α-L-fucosyltransferase (configuration-inverting)
Comments: This enzyme is the product of the Lewis blood group gene. Normally acts on a glycoconjugate where R (see reaction) is a glycoprotein or glycolipid. Although it is a 4-fucosyltransferase, it has a persistent 3-fucosyltransferase activity towards the glucose residue in free lactose. This enzyme fucosylates on O-4 of an N-acetylglucosamine that carries a galactosyl group on O-3, unlike EC 2.4.1.152, 4-galactosyl-N-acetylglucosaminide 3-α-L-fucosyltransferase, which fucosylates on O-3 of an N-acetylglucosamine that carries a galactosyl group on O-4. Enzymes catalysing the 4-α-fucosylation of the GlcNAc in β-D-Gal-(1→3)-β-GlcNAc sequences (with some activity also as 3-α-fucosyltransferases) are present in plants, where the function in vivo is the modification of N-glycans. In addition, the fucTa gene of Helicobacter strain UA948 encodes a fucosyltransferase with both 3-α- and 4-α-fucosyltransferase activities.
References:
1.  Prieels, J.-P., Monnom, D., Dolmans, M., Beyer, T.A. and Hill, R.L. Co-purification of the Lewis blood group N-acetylglucosaminide α1→4 fucosyltransferase and an N-acetylglucosaminide α1→3 fucosyltransferase from human milk. J. Biol. Chem. 256 (1981) 10456–10463. [PMID: 7287719]
2.  Rasko, D.A., Wang, G., Palcic, M.M. and Taylor, D.E. Cloning and characterization of the α(1,3/4) fucosyltransferase of Helicobacter pylori. J. Biol. Chem. 275 (2000) 4988–4994. [PMID: 10671538]
3.  Wilson, I.B.H. Identification of a cDNA encoding a plant Lewis-type α1,4-fucosyltransferase. Glycoconj. J. 18 (2001) 439–447. [PMID: 12084979]
4.  Ma, B., Wang, G., Palcic, M.M., Hazes, B. and Taylor, D.E. C-terminal amino acids of Helicobacter pylori α1,3/4 fucosyltransferases determine type I and type II transfer. J. Biol. Chem. 278 (2003) 21893–21900. [PMID: 12676935]
[EC 2.4.1.65 created 1972, modified 2001, modified twice 2002]
 
 
EC 2.4.1.48     Relevance: 15.6%
Accepted name: heteroglycan α-mannosyltransferase
Reaction: GDP-mannose + heteroglycan = GDP + 2(or 3)-α-D-mannosyl-heteroglycan
Other name(s): GDP mannose α-mannosyltransferase; guanosine diphosphomannose-heteroglycan α-mannosyltransferase
Systematic name: GDP-mannose:heteroglycan 2-(or 3-)-α-D-mannosyltransferase
Comments: The acceptor is a heteroglycan primer containing mannose, galactose and xylose. 1,2- and 1,3-mannosyl bonds are formed.
References:
1.  Ankel, H., Ankel, E., Schutzbach, J. and Garancis, J.C. Mannosyl transfer in Cryptococcus laurentii. J. Biol. Chem. 245 (1970) 3945–3955. [PMID: 5492958]
[EC 2.4.1.48 created 1972]
 
 
EC 3.1.3.83     Relevance: 15.6%
Accepted name: D-glycero-α-D-manno-heptose 1,7-bisphosphate 7-phosphatase
Reaction: D-glycero-α-D-manno-heptose 1,7-bisphosphate + H2O = D-glycero-α-D-manno-heptose 1-phosphate + phosphate
Other name(s): gmhB (gene name)
Systematic name: D-glycero-α-D-manno-heptose 1,7-bisphosphate 7-phosphohydrolase
Comments: The enzyme is involved in biosynthesis of GDP-D-glycero-α-D-manno-heptose, which is required for assembly of S-layer glycoprotein in some Gram-positive bacteria. The in vitro catalytic efficiency of the enzyme from Bacteroides thetaiotaomicron is 6-fold higher with the α-anomer than with the β-anomer [1].
References:
1.  Wang, L., Huang, H., Nguyen, H.H., Allen, K.N., Mariano, P.S. and Dunaway-Mariano, D. Divergence of biochemical function in the HAD superfamily: D-glycero-D-manno-heptose-1,7-bisphosphate phosphatase (GmhB). Biochemistry 49 (2010) 1072–1081. [PMID: 20050615]
[EC 3.1.3.83 created 2010]
 
 
EC 3.2.1.215     Relevance: 15.5%
Accepted name: arabinogalactan exo α-(1,3)-α-D-galactosyl-(1→3)-L-arabinofuranosidase (non-reducing end)
Reaction: Hydrolysis of α-D-Galp-(1→3)-L-Araf disaccharides from non-reducing terminals in branches of type II arabinogalactan attached to proteins.
Glossary: Araf = arabinofuranose
Arap = arabinopyranose
Galp = galactopyranose
Other name(s): 3-O-α-D-galactosyl-α-L-arabinofuranosidase
Systematic name: type II arabinogalactan exo α-(1,3)-[α-D-galactosyl-(1→3)-L-arabinofuranose] hydrolase (non-reducing end)
Comments: The enzyme, characterized from the bacterium Bifidobacterium longum, specifically hydrolyses α-D-Galp-(1→3)-L-Araf disaccharides from the non-reducing terminal of arabinogalactan using an exo mode of action. It is particularly active with gum arabic arabinogalactan, a type II arabinogalactan produced by acacia trees. The enzyme can also hydrolyse β-L-Arap-(1→3)-L-Araf disaccharides, but this activity is significantly lower.
References:
1.  Sasaki, Y., Horigome, A., Odamaki, T., Xiao, J.Z., Ishiwata, A., Ito, Y., Kitahara, K. and Fujita, K. Characterization of a novel 3-O-α-D-galactosyl-α-L-arabinofuranosidase for the assimilation of gum arabic AGP in Bifidobacterium longum subsp. longum. Appl. Environ. Microbiol. (2021) . [PMID: 33674431]
[EC 3.2.1.215 created 2021]
 
 
EC 2.7.7.12     Relevance: 15.5%
Accepted name: UDP-glucose—hexose-1-phosphate uridylyltransferase
Reaction: UDP-α-D-glucose + α-D-galactose 1-phosphate = α-D-glucose 1-phosphate + UDP-α-D-galactose
Other name(s): uridyl transferase; hexose-1-phosphate uridylyltransferase; uridyltransferase; hexose 1-phosphate uridyltransferase; UDP-glucose:α-D-galactose-1-phosphate uridylyltransferase
Systematic name: UDP-α-D-glucose:α-D-galactose-1-phosphate uridylyltransferase
References:
1.  Kalckar, H.M., Braganca, B. and Munch-Petersen, A. Uridyl transferases and the formation of uridinediphosphogalactose. Nature 172 (1953) 1038. [PMID: 13111247]
2.  Kurahashi, K. and Sugimura, A. Purification and properties of galactose 1-phosphate uridyl transferase from Escherichia coli. J. Biol. Chem. 235 (1960) 940–946. [PMID: 14412847]
3.  Mayes, J.S. and Hansen, R.G. Galactose 1-phosphate uridyl transferase. Methods Enzymol. 9 (1966) 708–713.
4.  Saito, S., Ozutsumi, M. and Kurahashi, K. Galactose 1-phosphate uridylyltransferase of Escherichia coli. II. Further purification and characterization. J. Biol. Chem. 242 (1967) 2362–2368. [PMID: 5338129]
5.  Smith, E.E.B. and Mills, G.T. The uridyl transferase of mammary gland. Biochim. Biophys. Acta 18 (1955) 152. [PMID: 13260264]
[EC 2.7.7.12 created 1961]
 
 
EC 3.2.1.48     Relevance: 15.5%
Accepted name: sucrose α-glucosidase
Reaction: Hydrolysis of sucrose and maltose by an α-D-glucosidase-type action
Other name(s): sucrose α-glucohydrolase; sucrase; sucrase-isomaltase; sucrose.α.-glucohydrolase; intestinal sucrase; sucrase(invertase)
Systematic name: sucrose-α-D-glucohydrolase
Comments: This enzyme is isolated from intestinal mucosa as a single polypeptide chain that also displays activity towards isomaltose (EC 3.2.1.10 oligo-1,6-glucosidase).
References:
1.  Conklin, K.A., Yamashiro, K.M. and Gray, G.M. Human intestinal sucrase-isomaltase. Identification of free sucrase and isomaltase and cleavage of the hybrid into active distinct subunits. J. Biol. Chem. 250 (1975) 5735–5741. [PMID: 807575]
2.  Hauri, H.-P., Quaroni, A. and Isselbacher, K.J. Biogenesis of intestinal plasma membrane: posttranslational route and cleavage of sucrase-isomaltase. Proc. Natl. Acad. Sci. USA 76 (1979) 5183–5186. [PMID: 291933]
3.  Kolinska, J. and Kraml, J. Separation and characterization of sucrose-isomaltase and of glucoamylase of rat intestine. Biochim. Biophys. Acta 284 (1972) 235–247. [PMID: 5073761]
4.  Sigrist, H., Ronner, P. and Semenza, G. A hydrophobic form of the small-intestinal sucrase-isomaltase complex. Biochim. Biophys. Acta 406 (1975) 433–446. [PMID: 1182172]
5.  Sjöström, H., Norén, O., Christiansen, L., Wacker, H. and Semenza, G. A fully active, two-active-site, single-chain sucrase-isomaltase from pig small intestine. Implications for the biosynthesis of a mammalian integral stalked membrane protein. J. Biol. Chem. 255 (1980) 11332–11338. [PMID: 7002920]
6.  Takesue, Y. Purification and properties of rabbit intestinal sucrase. J. Biochem. (Tokyo) 65 (1969) 545–552. [PMID: 5804876]
[EC 3.2.1.48 created 1972]
 
 
EC 1.1.1.384     Relevance: 15.5%
Accepted name: dTDP-3,4-didehydro-2,6-dideoxy-α-D-glucose 3-reductase
Reaction: dTDP-4-dehydro-2,6-dideoxy-α-D-glucose + NADP+ = dTDP-3,4-didehydro-2,6-dideoxy-α-D-glucose + NADPH + H+
Glossary: dTDP-4-dehydro-2,6-dideoxy-α-D-glucose = dTDP-2,6-dideoxy-α-D-threo-hexopyranos-4-ulose
dTDP-3,4-didehydro-2,6-dideoxy-α-D-glucose = thymidine 5′-[(2R,6R)-6-methyl-4,5-dioxotetrahydro-2H-pyran-2-yl] diphosphate
Other name(s): KijD10; dTDP-4-keto-2,6-dideoxy-D-glucose 3-oxidoreductase; dTDP-4-dehydro-2,6-dideoxy-α-D-glucose 3-oxidoreductase
Systematic name: dTDP-4-dehydro-2,6-dideoxy-α-D-glucose:NADP+ 3-oxidoreductase
Comments: The enzyme is involved in the biosynthesis of several deoxysugars, including L-digitoxose, L- and D-olivose, L-oliose, D-mycarose and forosamine.
References:
1.  Aguirrezabalaga, I., Olano, C., Allende, N., Rodriguez, L., Brana, A.F., Mendez, C. and Salas, J.A. Identification and expression of genes involved in biosynthesis of L-oleandrose and its intermediate L-olivose in the oleandomycin producer Streptomyces antibioticus. Antimicrob. Agents Chemother. 44 (2000) 1266–1275. [PMID: 10770761]
2.  Wang, L., White, R.L. and Vining, L.C. Biosynthesis of the dideoxysugar component of jadomycin B: genes in the jad cluster of Streptomyces venezuelae ISP5230 for L-digitoxose assembly and transfer to the angucycline aglycone. Microbiology 148 (2002) 1091–1103. [PMID: 11932454]
3.  Hong, L., Zhao, Z., Melancon, C.E., 3rd, Zhang, H. and Liu, H.W. In vitro characterization of the enzymes involved in TDP-D-forosamine biosynthesis in the spinosyn pathway of Saccharopolyspora spinosa. J. Am. Chem. Soc. 130 (2008) 4954–4967. [PMID: 18345667]
4.  Kubiak, R.L. and Holden, H.M. Combined structural and functional investigation of a C-3′′-ketoreductase involved in the biosynthesis of dTDP-L-digitoxose. Biochemistry 50 (2011) 5905–5917. [PMID: 21598943]
[EC 1.1.1.384 created 2015]
 
 
EC 3.2.1.10     Relevance: 15.5%
Accepted name: oligo-1,6-glucosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in some oligosaccharides produced from starch and glycogen by EC 3.2.1.1 (α-amylase), and in isomaltose
Other name(s): limit dextrinase (erroneous); isomaltase; sucrase-isomaltase; exo-oligo-1,6-glucosidase; dextrin 6α-glucanohydrolase; α-limit dextrinase; dextrin 6-glucanohydrolase; oligosaccharide α-1,6-glucohydrolase; α-methylglucosidase
Systematic name: oligosaccharide 6-α-glucohydrolase
Comments: This enzyme, like EC 3.2.1.33 (amylo-α-1,6-glucosidase), can release an α-1→6-linked glucose, whereas the shortest chain that can be released by EC 3.2.1.41 (pullulanase), EC 3.2.1.142 (limit dextrinase), and EC 3.2.1.68 (isoamylase) is maltose. It also hydrolyses isomaltulose (palatinose), isomaltotriose and panose, but has no action on glycogen or phosphorylase limit dextrin. The enzyme from intestinal mucosa is a single polypeptide chain that also catalyses the reaction of EC 3.2.1.48 (sucrose α-glucosidase). Differs from EC 3.2.1.33 (amylo-α-1,6-glucosidase) in its preference for short-chain substrates and in its not requiring the 6-glucosylated residue to be at a branch point, i.e. linked at both C-1 and C-4.
References:
1.  Hauri, H.-P., Quaroni, A. and Isselbacher, K.J. Biogenesis of intestinal plasma membrane: posttranslational route and cleavage of sucrase-isomaltase. Proc. Natl. Acad. Sci. USA 76 (1979) 5183–5186. [PMID: 291933]
2.  Sjöström, H., Norén, O., Christiansen, L., Wacker, H. and Semenza, G. A fully active, two-active-site, single-chain sucrase-isomaltase from pig small intestine. Implications for the biosynthesis of a mammalian integral stalked membrane protein. J. Biol. Chem. 255 (1980) 11332–11338. [PMID: 7002920]
3.  Rodriguez, I.R., Taravel, F.R. and Whelan, W.J. Characterization and function of pig intestinal sucrase-isomaltase and its separate subunits. Eur. J. Biochem. 143 (1984) 575–582. [PMID: 6479163]
4.  Khan, N.A. and Eaton, N.R. Purification and characterization of maltase and α-methyl glucosidase from yeast. Biochim. Biophys. Acta 146 (1967) 173–180. [PMID: 6060462]
5.  Yamamoto, K., Nakayama, A., Yamamoto, Y. and Tabata, S. Val216 decides the substrate specificity of α-glucosidase in Saccharomyces cerevisiae. Eur. J. Biochem. 271 (2004) 3414–3420. [PMID: 15291818]
[EC 3.2.1.10 created 1961, modified 2000, modified 2013]
 
 
EC 3.2.1.112     Relevance: 15.5%
Accepted name: 2-deoxyglucosidase
Reaction: a 2-deoxy-α-D-glucoside + H2O = 2-deoxy-D-glucose + an alcohol
Other name(s): 2-deoxy-α-glucosidase; 2-deoxy-α-D-glucosidase
Systematic name: 2-deoxy-α-D-glucoside deoxyglucohydrolase
References:
1.  Canellakis, Z.N., Bondy, P.K., May, J.A., Jr., Myers-Robfogel, M.K. and Sartorelli, A.C. Identification of a glycosidase activity with apparent specificity for 2-deoxy-D-glucose in glycosidic linkage. Eur. J. Biochem. 143 (1984) 159–163. [PMID: 6468386]
[EC 3.2.1.112 created 1986]
 
 
EC 2.4.1.228     Relevance: 15.5%
Accepted name: lactosylceramide 4-α-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): Galβ1-4Glcβ1-Cer α1,4-galactosyltransferase; globotriaosylceramide/CD77 synthase; histo-blood group Pk UDP-galactose; UDP-galactose:lactosylceramide 4II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl(1↔1)ceramide 4II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4II-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4II-α-D-galactosyltransferase
Comments: For explanation of superscript II in systematic name, see 2-carb.37.
References:
1.  Bailly, P., Piller, F., Cartron, J.P., Leroy, Y. and Fournet, B. Identification of UDP-galactose: lactose (lactosylceramide) α-4 and β-3 galactosyltransferases in human kidney. Biochem. Biophys. Res. Commun. 141 (1986) 84–91. [PMID: 3099784]
2.  Steffensen, R., Carlier, K., Wiels, J., Levery, S.B., Stroud, M., Cedergren, B., Nilsson Sojka, B., Bennett, E.P., Jersild, C. and Clausen, H. Cloning and expression of the histo-blood group Pk UDP-galactose: Galβ1-4Glcβ1-Cer α1,4-galactosyltransferase. Molecular genetic basis of the p phenotype. J. Biol. Chem. 275 (2000) 16723–16729. [PMID: 10747952]
3.  Kojima, Y., Fukumoto, S., Furukawa, K., Okajima, T., Wiels, J., Yokoyama, K., Suzuki, Y., Urano, T., Ohta, M. and Furukawa, K. Molecular cloning of globotriaosylceramide/CD77 synthase, a glycosyltransferase that initiates the synthesis of globo series glycosphingolipids. J. Biol. Chem. 275 (2000) 15152–15156. [PMID: 10748143]
[EC 2.4.1.228 created 2002]
 
 
EC 2.4.99.14     Relevance: 15.4%
Accepted name: (Kdo)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase
Reaction: α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA + CMP-β-Kdo = α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA + CMP
Glossary: (Kdo)2-lipid IVA = α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
(Kdo)3-lipid IVA = α-Kdo-(2→8)-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→8)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
CMP-β-Kdo = CMP-3-deoxy-β-D-manno-oct-2-ulopyranosylonate
Other name(s): Kdo transferase; waaA (gene name); kdtA (gene name); 3-deoxy-D-manno-oct-2-ulosonic acid transferase; 3-deoxy-manno-octulosonic acid transferase; (KDO)2-lipid IVA (2-8) 3-deoxy-D-manno-octulosonic acid transferase
Systematic name: CMP-3-deoxy-D-manno-oct-2-ulosonate:(Kdo)2-lipid IVA 3-deoxy-D-manno-oct-2-ulosonate transferase [(2→8) glycosidic bond-forming]
Comments: The enzymes from Chlamydia transfer three or more 3-deoxy-D-manno-oct-2-ulosonate residues and generate genus-specific epitopes.
References:
1.  Lobau, S., Mamat, U., Brabetz, W. and Brade, H. Molecular cloning, sequence analysis, and functional characterization of the lipopolysaccharide biosynthetic gene kdtA encoding 3-deoxy-α-D-manno-octulosonic acid transferase of Chlamydia pneumoniae strain TW-183. Mol. Microbiol. 18 (1995) 391–399. [PMID: 8748024]
2.  Mamat, U., Baumann, M., Schmidt, G. and Brade, H. The genus-specific lipopolysaccharide epitope of Chlamydia is assembled in C. psittaci and C. trachomatis by glycosyltransferases of low homology. Mol. Microbiol. 10 (1993) 935–941. [PMID: 7523826]
3.  Belunis, C.J., Mdluli, K.E., Raetz, C.R. and Nano, F.E. A novel 3-deoxy-D-manno-octulosonic acid transferase from Chlamydia trachomatis required for expression of the genus-specific epitope. J. Biol. Chem. 267 (1992) 18702–18707. [PMID: 1382060]
[EC 2.4.99.14 created 2010, modified 2011]
 
 
EC 2.1.1.305     Relevance: 15.4%
Accepted name: 8-demethyl-8-α-L-rhamnosyltetracenomycin-C 2′-O-methyltransferase
Reaction: S-adenosyl-L-methionine + 8-demethyl-8-α-L-rhamnosyltetracenomycin C = S-adenosyl-L-homocysteine + 8-demethyl-8-(2-O-methyl-α-L-rhamnosyl)tetracenomycin C
Glossary: 8-demethyl-8-α-L-rhamnosyltetracenomycin C = methyl (6aR,7S,10aR)-6a,7,10a,12-tetrahydroxy-8-methoxy-1-methyl-6,10,11-trioxo-3-α-L-rhamnosyloxy-6,6a,7,10,10a,11-hexahydrotetracene-2-carboxylate
Other name(s): ElmMI
Systematic name: S-adenosyl-L-methionine:8-demethyl-8-α-L-rhamnosyltetracenomycin-C 2′-O-methyltransferase
Comments: The enzyme from the bacterium Streptomyces olivaceus is involved in the biosynthesis of the polyketide elloramycin.
References:
1.  Patallo, E.P., Blanco, G., Fischer, C., Brana, A.F., Rohr, J., Mendez, C. and Salas, J.A. Deoxysugar methylation during biosynthesis of the antitumor polyketide elloramycin by Streptomyces olivaceus. Characterization of three methyltransferase genes. J. Biol. Chem. 276 (2001) 18765–18774. [PMID: 11376004]
[EC 2.1.1.305 created 2014]
 
 
EC 1.1.99.2     Relevance: 15.4%
Accepted name: L-2-hydroxyglutarate dehydrogenase
Reaction: (S)-2-hydroxyglutarate + acceptor = 2-oxoglutarate + reduced acceptor
Other name(s): α-ketoglutarate reductase; α-hydroxyglutarate dehydrogenase; L-α-hydroxyglutarate dehydrogenase; hydroxyglutaric dehydrogenase; α-hydroxyglutarate oxidoreductase; L-α-hydroxyglutarate:NAD+ 2-oxidoreductase; α-hydroxyglutarate dehydrogenase (NAD+ specific); (S)-2-hydroxyglutarate:(acceptor) 2-oxidoreductase
Systematic name: (S)-2-hydroxyglutarate:acceptor 2-oxidoreductase
References:
1.  Weil-Malherbe, H. The oxidation of l(–)α-hydroxyglutaric acid in animal tissues. Biochem. J. 31 (1937) 2080–2094. [PMID: 16746551]
[EC 1.1.99.2 created 1961, modified 2013]
 
 
EC 4.2.2.11     Relevance: 15.4%
Accepted name: guluronate-specific alginate lyase
Reaction: Eliminative cleavage of alginate to give oligosaccharides with 4-deoxy-α-L-erythro-hex-4-enuronosyl groups at their non-reducing ends and α-L-guluronate at their reducing end.
Other name(s): alginase II; guluronate lyase; L-guluronan lyase; L-guluronate lyase; poly-α-L-guluronate lyase; polyguluronate-specific alginate lyase; poly(α-L-1,4-guluronide) exo-lyase; poly(α-L-guluronate) lyase; poly[(1→4)-α-L-guluronide] exo-lyase
Systematic name: alginate α-L-guluronate—uronate lyase
Comments: The enzyme catalyses the degradation of alginate by a β-elimination reaction. It cleaves the (1→4) bond between α-L-guluronate and either α-L-guluronate or β-D-mannuronate, generating oligosaccharides with 4-deoxy-α-L-erythro-hex-4-enuronosyl groups at their non-reducing ends and α-L-guluronate at the reducing end. Depending on the composition of the substrate, the enzyme produces oligosaccharides ranging from two to six residues, with preference for shorter products. cf. EC 4.2.2.3, mannuronate-specific alginate lyase.
References:
1.  Boyd, J. and Turvey, J.R. Isolation of poly-α-L-guluronate lyase from Klebsiella aerogenes. Carbohydr. Res. 57 (1977) 163–171. [PMID: 332364]
2.  Davidson, I.W., Sutherland, I.W. and Lawson, C.J. Purification and properties of an alginate lyase from a marine bacterium. Biochem. J. 159 (1976) 707–713. [PMID: 1008828]
[EC 4.2.2.11 created 1990, modified 2015]
 
 
EC 3.2.1.101     Relevance: 15.4%
Accepted name: mannan endo-1,6-α-mannosidase
Reaction: Random hydrolysis of (1→6)-α-D-mannosidic linkages in unbranched (1→6)-mannans
Other name(s): endo-α-1→6-D-mannanase; endo-1,6-β-mannanase; mannan endo-1,6-β-mannosidase; 1,6-α-D-mannan mannanohydrolase
Systematic name: 6-α-D-mannan mannanohydrolase
References:
1.  Nakajima, T., Maitra, S.K. and Ballou, C.E. An endo-α-1→6-D-mannanase from a soil bacterium. Purification, properties, and mode of action. J. Biol. Chem. 251 (1976) 174–181. [PMID: 811665]
2.  Brigance, W.T., Barlowe, C. and Graham, T.R. Organization of the yeast Golgi complex into at least four functionally distinct compartments. Mol. Biol. Cell 11 (2000) 171–182. [PMID: 10637300]
3.  Nakajima, T. and Ballou, C.E. Structure of the linkage region between the polysaccharide and protein parts of Saccharomyces cerevisiae mannan. J. Biol. Chem. 249 (1974) 7685–7694. [PMID: 4612041]
[EC 3.2.1.101 created 1984, modified 2001]
 
 
EC 2.4.3.4     Relevance: 15.4%
Accepted name: β-galactoside α-2,3-sialyltransferase
Reaction: CMP-N-acetylneuraminate + β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-R = CMP + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-R
Other name(s): CMP-N-acetylneuraminate:β-D-galactoside α-2,3-N-acetylneuraminyl-transferase
Systematic name: CMP-N-acetylneuraminate:β-D-galactoside α-(2→3)-N-acetylneuraminyl-transferase
Comments: The acceptor is Galβ1,3GalNAc-R, where R is H, a threonine or serine residue in a glycoprotein, or a glycolipid. Lactose can also act as acceptor. May be identical with EC 2.4.3.2 β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase.
References:
1.  Rearick, J.I., Sadler, J.E., Paulson, J.C. and Hill, R.L. Enzymatic characterization of β D-galactoside α2→3 sialyltransferase from porcine submaxillary gland. J. Biol. Chem. 254 (1979) 4444–4451. [PMID: 438198]
2.  Sadler, J.E., Rearick, J.I., Paulson, J.C. and Hill, R.L. Purification to homogeneity of a β-galactoside α2→3 sialyltransferase and partial purification of an α-N-acetylgalactosaminide α2→6 sialyltransferase from porcine submaxillary glands. J. Biol. Chem. 254 (1979) 4434–4442. [PMID: 438196]
[EC 2.4.3.4 created 1984 as EC 2.4.99.4, modified 1986, transferred 2022 to EC 2.4.3.4]
 
 
EC 1.3.3.10     Relevance: 15.4%
Accepted name: tryptophan α,β-oxidase
Reaction: L-tryptophan + O2 = α,β-didehydrotryptophan + H2O2
Other name(s): L-tryptophan 2′,3′-oxidase; L-tryptophan α,β-dehydrogenase
Systematic name: L-tryptophan:oxygen α,β-oxidoreductase
Comments: Requires heme. The enzyme from Chromobacterium violaceum is specific for tryptophan derivatives possessing its carboxyl group free or as an amide or ester, and an unsubstituted indole ring. Also catalyses the α,β dehydrogenation of L-tryptophan side chains in peptides. The product of the reaction can hydrolyse spontaneously to form (indol-3-yl)pyruvate.
References:
1.  Genet, R., Denoyelle, C. and Menez, A. Purification and partial characterization of an amino acid α,β-dehydrogenase, L-tryptophan 2′,3′-oxidase from Chromobacterium violaceum. J. Biol. Chem. 269 (1994) 18177–18184. [PMID: 8027079]
2.  Genet, R., Benetti, P.H., Hammadi, A. and Menez, A. L-Tryptophan 2′,3′-oxidase from Chromobacterium violaceum. Substrate specificity and mechanistic implications. J. Biol. Chem. 270 (1995) 23540–23545. [PMID: 7559518]
[EC 1.3.3.10 created 2000 as EC 1.4.3.17, transferred 2003 to EC 1.3.3.10]
 
 
EC 2.4.1.208     Relevance: 15.4%
Accepted name: diglucosyl diacylglycerol synthase (1,2-linking)
Reaction: UDP-α-D-glucose + 1,2-diacyl-3-O-(α-D-glucopyranosyl)-sn-glycerol = 1,2-diacyl-3-O-[α-D-glucopyranosyl-(1→2)-O-α-D-glucopyranosyl]-sn-glycerol + UDP
Other name(s): monoglucosyl diacylglycerol (1→2) glucosyltransferase; MGlcDAG (1→2) glucosyltransferase; DGlcDAG synthase (ambiguous); UDP-glucose:1,2-diacyl-3-O-(α-D-glucopyranosyl)-sn-glycerol (1→2) glucosyltransferase; diglucosyl diacylglycerol synthase
Systematic name: UDP-α-D-glucose:1,2-diacyl-3-O-(α-D-glucopyranosyl)-sn-glycerol 2-glucosyltransferase
Comments: The enzyme from Acholeplasma laidlawii requires Mg2+.
References:
1.  Karlsson, O.P., Rytomaa, M., Dahlqvist, A., Kinnunen, P.K., Wieslander, A. Correlation between bilayer lipid dynamics and activity of the diglucosyldiacylglycerol synthase from Acholeplasma laidlawii membranes. Biochemistry 35 (1996) 10094–10102. [PMID: 8756472]
[EC 2.4.1.208 created 1999, modified 2014]
 
 
EC 1.14.14.113     Relevance: 15.4%
Accepted name: α-humulene 10-hydroxylase
Reaction: α-humulene + O2 + [reduced NADPH—hemoprotein reductase] = 10-hydroxy-α-humulene + [oxidized NADPH—hemoprotein reductase] + H2O
Other name(s): CYP71BA1
Systematic name: α-humulene,[reduced NADPH—hemoprotein reductase]:oxygen 10-oxidoreductase
Comments: A cytochrome P-450 (heme-thiolate) protein. The recommended numbering of humulene gives 10-hydroxy-α-humulene as the product rather than 8-hydroxy-α-humulene as used by the reference. See Section F: Natural Product Nomenclature.
References:
1.  Yu, F., Okamoto, S., Harada, H., Yamasaki, K., Misawa, N. and Utsumi, R. Zingiber zerumbet CYP71BA1 catalyzes the conversion of α-humulene to 8-hydroxy-α-humulene in zerumbone biosynthesis. Cell. Mol. Life Sci. 68 (2011) 1033–1040. [PMID: 20730551]
[EC 1.14.14.113 created 2012 as EC 1.14.13.150, transferred 2018 to EC 1.14.14.113]
 
 
EC 4.2.3.86     Relevance: 15.4%
Accepted name: 7-epi-α-selinene synthase
Reaction: (2E,6E)-farnesyl diphosphate = 7-epi-α-selinene + diphosphate
Glossary: 7-epi-α-selinene = (2S,4aR,8aR)-4a,8-dimethyl-2-(prop-1-en-2-yl)-1,2,3,4,4a,5,6,8a-octahydronaphthalene
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase (7-epi-α-selinene-forming)
Comments: The recombinant enzyme from Vitis vinifera forms 49.5% (+)-valencene (cf. EC 4.2.3.73, valencene synthase) and 35.5% (-)-7-epi-α-selinene. Initial cyclization gives (+)-germacrene A in an enzyme bound form which is not released to the medium.
References:
1.  Lucker, J., Bowen, P. and Bohlmann, J. Vitis vinifera terpenoid cyclases: functional identification of two sesquiterpene synthase cDNAs encoding (+)-valencene synthase and (-)-germacrene D synthase and expression of mono- and sesquiterpene synthases in grapevine flowers and berries. Phytochemistry 65 (2004) 2649–2659. [PMID: 15464152]
2.  Martin, D.M., Toub, O., Chiang, A., Lo, B.C., Ohse, S., Lund, S.T. and Bohlmann, J. The bouquet of grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) flowers arises from the biosynthesis of sesquiterpene volatiles in pollen grains. Proc. Natl. Acad. Sci. USA 106 (2009) 7245–7250. [PMID: 19359488]
[EC 4.2.3.86 created 2011]
 
 
EC 3.2.1.68     Relevance: 15.4%
Accepted name: isoamylase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic branch linkages in glycogen, amylopectin and their β-limit dextrins
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Other name(s): debranching enzyme; glycogen α-1,6-glucanohydrolase
Systematic name: glycogen 6-α-D-glucanohydrolase
Comments: Also readily hydrolyses amylopectin. Differs from EC 3.2.1.41 (pullulanase) and EC 3.2.1.142 (limit dextrinase) by its inability to hydrolyse pullulan, and by limited action on α-limit dextrins. Maltose is the smallest sugar it can release from an α-(1→6)-linkage.
References:
1.  Yokobayashi, K., Misaki, A. and Harada, T. Purification and properties of Pseudomonas isoamylase. Biochim. Biophys. Acta 212 (1970) 458–469. [PMID: 5456995]
[EC 3.2.1.68 created 1972, modified 1976, modified 2000]
 
 
EC 4.2.2.15     Relevance: 15.4%
Accepted name: anhydrosialidase
Reaction: Elimination of α-sialyl groups in N-acetylneuraminic acid glycosides, releasing 2,7-anhydro-α-N-acetylneuraminate
Other name(s): anhydroneuraminidase; sialglycoconjugate N-acylneuraminylhydrolase (2,7-cyclizing); sialidase L
Systematic name: glycoconjugate sialyl-lyase (2,7-cyclizing)
Comments: Also acts on N-glycolylneuraminate glycosides. cf. EC 3.2.1.18 (exo-α-sialidase) and EC 3.2.1.129 (endo-α-sialidase).
References:
1.  Li, Y.-T., Nakagawa, H., Ross, S.A., Hansson, G.C. and Li, S.C. A novel sialidase which releases 2,7-anhydro-α-N-acetylneuraminic acid from sialoglycoconjugates. J. Biol. Chem. 265 (1990) 21629–21633. [PMID: 2254319]
[EC 4.2.2.15 created 1992 as EC 3.2.1.138, transferred 2003 to EC 4.2.2.15]
 
 
EC 1.1.1.364     Relevance: 15.3%
Accepted name: dTDP-4-dehydro-6-deoxy-α-D-gulose 4-ketoreductase
Reaction: dTDP-6-deoxy-α-D-allose + NAD(P)+ = dTDP-4-dehydro-6-deoxy-α-D-gulose + NAD(P)H + H+
Glossary: dTDP-4-dehydro-6-deoxy-α-D-gulose = dTDP-4-dehydro-6-deoxy-α-D-allose
Other name(s): dTDP-4-dehydro-6-deoxygulose reductase; tylD (gene name); gerKI (gene name); chmD (gene name); mydI (gene name)
Systematic name: dTDP-6-deoxy-α-D-allose:NAD(P)+ oxidoreductase
Comments: The enzyme forms an activated deoxy-α-D-allose, which is converted to mycinose after attachment to the aglycones of several macrolide antibiotics, including tylosin, chalcomycin, dihydrochalcomycin, and mycinamicin II.
References:
1.  Bate, N. and Cundliffe, E. The mycinose-biosynthetic genes of Streptomyces fradiae, producer of tylosin. J Ind Microbiol Biotechnol 23 (1999) 118–122. [PMID: 10510490]
2.  Anzai, Y., Saito, N., Tanaka, M., Kinoshita, K., Koyama, Y. and Kato, F. Organization of the biosynthetic gene cluster for the polyketide macrolide mycinamicin in Micromonospora griseorubida. FEMS Microbiol. Lett. 218 (2003) 135–141. [PMID: 12583909]
3.  Thuy, T.T., Liou, K., Oh, T.J., Kim, D.H., Nam, D.H., Yoo, J.C. and Sohng, J.K. Biosynthesis of dTDP-6-deoxy-β-D-allose, biochemical characterization of dTDP-4-keto-6-deoxyglucose reductase (GerKI) from Streptomyces sp. KCTC 0041BP. Glycobiology 17 (2007) 119–126. [PMID: 17053005]
4.  Kubiak, R.L., Phillips, R.K., Zmudka, M.W., Ahn, M.R., Maka, E.M., Pyeatt, G.L., Roggensack, S.J. and Holden, H.M. Structural and functional studies on a 3′-epimerase involved in the biosynthesis of dTDP-6-deoxy-D-allose. Biochemistry 51 (2012) 9375–9383. [PMID: 23116432]
[EC 1.1.1.364 created 2013]
 
 
EC 2.3.1.265     Relevance: 15.3%
Accepted name: phosphatidylinositol dimannoside acyltransferase
Reaction: (1) an acyl-CoA + 2,6-di-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol = CoA + 2-O-(6-O-acyl-α-D-mannosyl)-6-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol
(2) an acyl-CoA + 2-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol = CoA + 2-O-(6-O-acyl-α-D-mannosyl)-1-phosphatidyl-1D-myo-inositol
Other name(s): PIM2 acyltransferase; ptfP1 (gene name)
Systematic name: acyl-CoA:2,6-di-O-α-D-mannosyl-1-phosphatidyl-1D-myo-inositol acyltransferase
Comments: The enzyme, found in Corynebacteriales, is involved in the biosynthesis of phosphatidyl-myo-inositol mannosides (PIMs).
References:
1.  Svetlikova, Z., Barath, P., Jackson, M., Kordulakova, J. and Mikusova, K. Purification and characterization of the acyltransferase involved in biosynthesis of the major mycobacterial cell envelope glycolipid—monoacylated phosphatidylinositol dimannoside. Protein Expr. Purif. 100 (2014) 33–39. [PMID: 24810911]
[EC 2.3.1.265 created 2017]
 
 
EC 2.4.1.52     Relevance: 15.3%
Accepted name: poly(glycerol-phosphate) α-glucosyltransferase
Reaction: n UDP-α-D-glucose + 4-O-{poly[(2R)-glycerophospho]-(2R)-glycerophospho}-N-acetyl-β-D-mannosaminyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = n UDP + 4-O-{poly[(2R)-2-α-D-glucosyl-1-glycerophospho]-(2R)-glycerophospho}-N-acetyl-β-D-mannosaminyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol
Other name(s): UDP glucose-poly(glycerol-phosphate) α-glucosyltransferase; uridine diphosphoglucose-poly(glycerol-phosphate) α-glucosyltransferase; tagE (gene name); UDP-glucose:poly(glycerol-phosphate) α-D-glucosyltransferase
Systematic name: UDP-α-D-glucose:4-O-{poly[(2R)-glycerophospho]-(2R)-glycerophospho}-N-acetyl-β-D-mannosaminyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol α-D-glucosyltransferase (configuration-retaining)
Comments: Involved in the biosynthesis of poly glycerol phosphate teichoic acids in bacterial cell walls. This enzyme, isolated from Bacillus subtilis 168, adds an α-D-glucose to the free OH groups of the glycerol units. The enzyme has a strong preference for UDP-α-glucose as the sugar donor. It has no activity with poly(ribitol phosphate).
References:
1.  Glaser, L. and Burger, M.M. The synthesis of teichoic acids. 3. Glucosylation of polyglycerophosphate. J. Biol. Chem. 239 (1964) 3187–3191. [PMID: 14245359]
2.  Allison, S.E., D'Elia, M.A., Arar, S., Monteiro, M.A. and Brown, E.D. Studies of the genetics, function, and kinetic mechanism of TagE, the wall teichoic acid glycosyltransferase in Bacillus subtilis 168. J. Biol. Chem. 286 (2011) 23708–23716. [PMID: 21558268]
[EC 2.4.1.52 created 1972, modified 2017]
 
 
EC 5.4.99.16     Relevance: 15.3%
Accepted name: maltose α-D-glucosyltransferase
Reaction: maltose = α,α-trehalose
Other name(s): trehalose synthase; maltose glucosylmutase
Systematic name: maltose α-D-glucosylmutase
References:
1.  Nishimoto, T., Nakano, M., Ikegami, S., Chaen, H., Fukuda, S., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Existence of a novel enzyme converting maltose to trehalose. Biosci. Biotechnol. Biochem. 59 (1995) 2189–2190.
2.  Nishimoto, T., Nakano, M., Nakada, T., Chaen, H., Fukuda, S., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Purification and properties of a novel enzyme, trehalose synthase, from Pimelobacter sp. R48. Biosci. Biotechnol. Biochem. 60 (1996) 640–644. [PMID: 8829531]
[EC 5.4.99.16 created 1999]
 
 
EC 2.7.7.78     Relevance: 15.3%
Accepted name: GDP-D-glucose phosphorylase
Reaction: GDP-α-D-glucose + phosphate = α-D-glucose 1-phosphate + GDP
Systematic name: GDP:α-D-glucose 1-phosphate guanylyltransferase
Comments: The enzyme may be involved in prevention of misincorporation of glucose in place of mannose residues into glycoconjugates i.e. to remove accidentally produced GDP-α-D-glucose. Activities with GDP-L-galactose, GDP-D-mannose and UDP-D-glucose are all less than 3% that with GDP-D-glucose.
References:
1.  Adler, L.N., Gomez, T.A., Clarke, S.G. and Linster, C.L. A novel GDP-D-glucose phosphorylase involved in quality control of the nucleoside diphosphate sugar pool in Caenorhabditis elegans and mammals. J. Biol. Chem. 286 (2011) 21511–21523. [PMID: 21507950]
[EC 2.7.7.78 created 2011]
 
 
EC 2.4.1.282     Relevance: 15.3%
Accepted name: 3-O-α-D-glucosyl-L-rhamnose phosphorylase
Reaction: 3-O-α-D-glucopyranosyl-L-rhamnopyranose + phosphate = L-rhamnopyranose + β-D-glucose 1-phosphate
Other name(s): cphy1019 (gene name)
Systematic name: 3-O-α-D-glucopyranosyl-L-rhamnopyranose:phosphate β-D-glucosyltransferase
Comments: The enzyme does not phosphorylate α,α-trehalose, kojibiose, nigerose, or maltose. In the reverse phosphorolysis reaction the enzyme is specific for L-rhamnose as acceptor and β-D-glucose 1-phosphate as donor.
References:
1.  Nihira, T., Nakai, H. and Kitaoka, M. 3-O-α-D-glucopyranosyl-L-rhamnose phosphorylase from Clostridium phytofermentans. Carbohydr. Res. 350 (2012) 94–97. [PMID: 22277537]
[EC 2.4.1.282 created 2012]
 
 
EC 4.2.3.46     Relevance: 15.3%
Accepted name: α-farnesene synthase
Reaction: (2E,6E)-farnesyl diphosphate = (3E,6E)-α-farnesene + diphosphate
Other name(s): (E,E)-α-farnesene synthase; AFS1; MdAFS1
Systematic name: (2E,6E)-farnesyl-diphosphate lyase [(3E,6E)-α-farnesene-forming]
References:
1.  Pechous, S.W. and Whitaker, B.D. Cloning and functional expression of an (E,E)-α-farnesene synthase cDNA from peel tissue of apple fruit. Planta 219 (2004) 84–94. [PMID: 14740213]
2.  Green, S., Squire, C.J., Nieuwenhuizen, N.J., Baker, E.N. and Laing, W. Defining the potassium binding region in an apple terpene synthase. J. Biol. Chem. 284 (2009) 8661–8669. [PMID: 19181671]
3.  Nieuwenhuizen, N.J., Wang, M.Y., Matich, A.J., Green, S.A., Chen, X., Yauk, Y.K., Beuning, L.L., Nagegowda, D.A., Dudareva, N. and Atkinson, R.G. Two terpene synthases are responsible for the major sesquiterpenes emitted from the flowers of kiwifruit (Actinidia deliciosa). J. Exp. Bot. 60 (2009) 3203–3219. [PMID: 19516075]
[EC 4.2.3.46 created 2010]
 
 
EC 3.2.1.67     Relevance: 15.3%
Accepted name: galacturonan 1,4-α-galacturonidase
Reaction: [(1→4)-α-D-galacturonide]n + H2O = [(1→4)-α-D-galacturonide]n-1 + D-galacturonate
Other name(s): exo-polygalacturonase; poly(galacturonate) hydrolase (ambiguous); exo-D-galacturonase; exo-D-galacturonanase; exopoly-D-galacturonase; poly(1,4-α-D-galacturonide) galacturonohydrolase (ambiguous); pgaA (gene name); pgaB (gene name); pgaC (gene name); pgaD (gene name); pgaE (gene name); pgaI (gene name); pgaII (gene name); poly[(1→4)-α-D-galacturonide] galacturonohydrolase; galacturan 1,4-α-galacturonidase (incorrect)
Systematic name: poly[(1→4)-α-D-galacturonide] non-reducing-end galacturonohydrolase
Comments: The enzyme hydrolyses the first glycosidic bond from the non-reducing end of the substrate. It is specific for saturated oligomers of D-homogalacturonan, and is unable to degrade unsaturated substrates or methyl-esterified substrates.
References:
1.  Hasegawa, H. and Nagel, C.W. Isolation of an oligogalacturonate hydrolase from a Bacillus species. Arch. Biochem. Biophys. 124 (1968) 513–520. [PMID: 5661621]
2.  Kluskens, L.D., van Alebeek, G.J., Walther, J., Voragen, A.G., de Vos, W.M. and van der Oost, J. Characterization and mode of action of an exopolygalacturonase from the hyperthermophilic bacterium Thermotoga maritima. FEBS J. 272 (2005) 5464–5473. [PMID: 16262687]
3.  Martens-Uzunova, E.S., Zandleven, J.S., Benen, J.A., Awad, H., Kools, H.J., Beldman, G., Voragen, A.G., Van den Berg, J.A. and Schaap, P.J. A new group of exo-acting family 28 glycoside hydrolases of Aspergillus niger that are involved in pectin degradation. Biochem. J. 400 (2006) 43–52. [PMID: 16822232]
4.  Pijning, T., van Pouderoyen, G., Kluskens, L., van der Oost, J. and Dijkstra, B.W. The crystal structure of a hyperthermoactive exopolygalacturonase from Thermotoga maritima reveals a unique tetramer. FEBS Lett. 583 (2009) 3665–3670. [PMID: 19854184]
[EC 3.2.1.67 created 1972, modified 2019]
 
 
EC 2.4.1.303     Relevance: 15.3%
Accepted name: UDP-Gal:α-D-GlcNAc-diphosphoundecaprenol β-1,3-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = UDP + β-D-Gal-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbbD; WbbD β3Gal-transferase; UDP-Gal:GlcNAc-R β1,3-galactosyltransferase; UDP-Gal:GlcNAcα-pyrophosphate-R β1,3-galactosyltransferase; UDP-Gal:GlcNAc-R galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol 3-β-galactosyltransferase (configuration-inverting)
Comments: The enzyme is involved in the the biosynthesis of the O-antigen repeating unit of Escherichia coli O7:K1 (VW187). Requires Mn2+. cf. EC 2.4.1.343, UDP-Gal:α-D-GlcNAc-diphosphoundecaprenol α-1,3-galactosyltransferase.
References:
1.  Riley, J.G., Menggad, M., Montoya-Peleaz, P.J., Szarek, W.A., Marolda, C.L., Valvano, M.A., Schutzbach, J.S. and Brockhausen, I. The wbbD gene of E. coli strain VW187 (O7:K1) encodes a UDP-Gal: GlcNAcα-pyrophosphate-R β1,3-galactosyltransferase involved in the biosynthesis of O7-specific lipopolysaccharide. Glycobiology 15 (2005) 605–613. [PMID: 15625181]
2.  Brockhausen, I., Riley, J.G., Joynt, M., Yang, X. and Szarek, W.A. Acceptor substrate specificity of UDP-Gal: GlcNAc-R β1,3-galactosyltransferase (WbbD) from Escherichia coli O7:K1. Glycoconj. J. 25 (2008) 663–673. [PMID: 18536883]
[EC 2.4.1.303 created 2013, modified 2017]
 
 
EC 2.4.1.145     Relevance: 15.3%
Accepted name: α-1,3-mannosyl-glycoprotein 4-β-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein] = UDP + β-D-GlcNAc-(1→2)-[β-D-GlcNAc-(1→4)]-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc-N-Asn-[protein]
Other name(s): N-acetylglucosaminyltransferase IV; N-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase IV; β-acetylglucosaminyltransferase IV; uridine diphosphoacetylglucosamine-glycopeptide β4-acetylglucosaminyltransferase IV; α-1,3-mannosylglycoprotein β-1,4-N-acetylglucosaminyltransferase; GnTIV; UDP-N-acetyl-D-glucosamine:3-[2-(N-acetyl-β-D-glucosaminyl)-α-D-mannosyl]-glycoprotein 4-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→3)-β-D-mannosyl-glycoprotein 4-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: Requires Mn2+. The enzyme, found in vertebrates, participates in the processing of N-glycans in the Golgi apparatus. By adding a glucosaminyl residue to biantennary N-linked glycans, it enables the synthesis of tri- and tetra-antennary complexes.
References:
1.  Gleeson, P.A. and Schachter, H. Control of glycoprotein synthesis. J. Biol. Chem. 258 (1983) 6162–6173. [PMID: 6222042]
2.  Oguri, S., Minowa, M.T., Ihara, Y., Taniguchi, N., Ikenaga, H. and Takeuchi, M. Purification and characterization of UDP-N-acetylglucosamine: α1,3-D-mannoside β1,4-N-acetylglucosaminyltransferase (N-acetylglucosaminyltransferase-IV) from bovine small intestine. J. Biol. Chem. 272 (1997) 22721–22727. [PMID: 9278430]
3.  Minowa, M.T., Oguri, S., Yoshida, A., Hara, T., Iwamatsu, A., Ikenaga, H. and Takeuchi, M. cDNA cloning and expression of bovine UDP-N-acetylglucosamine: α1, 3-D-mannoside β1,4-N-acetylglucosaminyltransferase IV. J. Biol. Chem. 273 (1998) 11556–11562. [PMID: 9565571]
4.  Yoshida, A., Minowa, M.T., Takamatsu, S., Hara, T., Oguri, S., Ikenaga, H. and Takeuchi, M. Tissue specific expression and chromosomal mapping of a human UDP-N-acetylglucosamine: α1,3-d-mannoside β1, 4-N-acetylglucosaminyltransferase. Glycobiology 9 (1999) 303–310. [PMID: 10024668]
5.  Yoshida, A., Minowa, M.T., Takamatsu, S., Hara, T., Ikenaga, H. and Takeuchi, M. A novel second isoenzyme of the human UDP-N-acetylglucosamine:α1,3-D-mannoside β1,4-N-acetylglucosaminyltransferase family: cDNA cloning, expression, and chromosomal assignment. Glycoconj. J. 15 (1998) 1115–1123. [PMID: 10372966]
6.  Takamatsu, S., Antonopoulos, A., Ohtsubo, K., Ditto, D., Chiba, Y., Le, D.T., Morris, H.R., Haslam, S.M., Dell, A., Marth, J.D. and Taniguchi, N. Physiological and glycomic characterization of N-acetylglucosaminyltransferase-IVa and -IVb double deficient mice. Glycobiology 20 (2010) 485–497. [PMID: 20015870]
[EC 2.4.1.145 created 1984, modified 2001 (EC 2.4.1.51 created 1972, part incorporated 1984), modified 2018]
 
 
EC 3.2.1.41     Relevance: 15.3%
Accepted name: pullulanase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in pullulan, amylopectin and glycogen, and in the α- and β-limit dextrins of amylopectin and glycogen
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Other name(s): limit dextrinase (erroneous); amylopectin 6-glucanohydrolase; bacterial debranching enzyme; debranching enzyme; α-dextrin endo-1,6-α-glucosidase; R-enzyme; pullulan α-1,6-glucanohydrolase
Systematic name: pullulan 6-α-glucanohydrolase
Comments: Different from EC 3.2.1.142 (limit dextrinase) in its action on glycogen, and its rate of hydrolysis of limit dextrins. Its action on amylopectin is complete. Maltose is the smallest sugar that it can release from an α-(1→6)-linkage.
References:
1.  Lee, E.Y.C. and Whelan, W.J. Glycogen and starch debranching enzymes. In: Boyer, P.D. (Ed.), The Enzymes, 3rd edn, vol. 5, Academic Press, New York, 1972, pp. 191–234.
2.  Bender, H. and Wallenfels, K. Pullulanase (an amylopectin and glycogen debranching enzyme) from Aerobacter aerogenes. Methods Enzymol. 8 (1966) 555–559.
3.  Manners, D.J. Observations on the specificity and nomenclature of starch debranching enzymes. J. Appl. Glycosci. 44 (1997) 83–85.
[EC 3.2.1.41 created 1972, modified 1976, modified 2000 (EC 3.2.1.69 created 1972, incorporated 1976)]
 
 
EC 4.2.3.83     Relevance: 15.3%
Accepted name: β-santalene synthase
Reaction: (2E,6E)-farnesyl diphosphate = (-)-β-santalene + diphosphate
Glossary: (-)-exo-α-bergamotene = (-)-trans-α-bergamotene = (1S,5S,6R)-2,6-dimethyl-6-(4-methylpent-3-en-1-yl)bicyclo[3.1.1]hept-2-ene
Systematic name: (2E,6E)-farnesyl diphosphate lyase (cyclizing, (-)-β-santalene-forming)
Comments: The enzyme synthesizes a mixture of sesquiterpenoids from (2E,6E)-farnesyl diphosphate. As well as (-)-β-santalene (+)-α-santalene and (-)-exo-α-bergamotene are formed with traces of (+)-epi-β-santalene. See EC 4.2.3.82 [(+)-α-santalene synthase], and EC 4.2.3.81 [(-)-exo-α-bergamotene synthase].
References:
1.  Jones, C.G., Moniodis, J., Zulak, K.G., Scaffidi, A., Plummer, J.A., Ghisalberti, E.L., Barbour, E.L. and Bohlmann, J. Sandalwood fragrance biosynthesis involves sesquiterpene synthases of both the terpene synthase (TPS)-a and TPS-b subfamilies, including santalene synthases. J. Biol. Chem. 286 (2011) 17445–17454. [PMID: 21454632]
[EC 4.2.3.83 created 2011]
 
 
EC 4.2.3.121     Relevance: 15.3%
Accepted name: (+)-α-pinene synthase
Reaction: geranyl diphosphate = (+)-α-pinene + diphosphate
Glossary: (+)-α-pinene = (1R,5R)-2,6,6-trimethylbicyclo[3.1.1]hept-2-ene
Other name(s): (+)-α-pinene cyclase; cyclase I
Systematic name: geranyl-diphosphate diphosphate-lyase [cyclizing, (+)-α-pinene-forming]
Comments: Cyclase I of Salvia officinalis (sage) gives about equal parts (+)-α-pinene and (+)-camphene, whereas cyclase III gives about equal parts of (+)-α-pinene and (+)-β-pinene. (3R)-Linalyl diphosphate can also be used by the enzyme in preference to (3S)-linalyl diphosphate. The 4-pro-R-hydrogen of geranyl diphosphate is lost. Requires Mg2+ (preferred to Mn2+) [1-4]. With synthase II of Pinus taeda (loblolly pine) (+)-α-pinene was the only product [5,6]. Requires Mn2+ (preferred to Mg2+). See also EC 4.2.3.122, (+)-β-pinene synthase, and EC 4.2.3.116, (+)-camphene synthase.
References:
1.  Gambliel, H. and Croteau, R. Pinene cyclases I and II. Two enzymes from sage (Salvia officinalis) which catalyze stereospecific cyclizations of geranyl pyrophosphate to monoterpene olefins of opposite configuration. J. Biol. Chem. 259 (1984) 740–748. [PMID: 6693393]
2.  Croteau, R., Satterwhite, D.M., Cane, D.E. and Chang, C.C. Biosynthesis of monoterpenes. Enantioselectivity in the enzymatic cyclization of (+)- and (-)-linalyl pyrophosphate to (+)- and (-)-pinene and (+)- and (-)-camphene. J. Biol. Chem. 263 (1988) 10063–10071. [PMID: 3392006]
3.  Wagschal, K.C., Pyun, H.J., Coates, R.M. and Croteau, R. Monoterpene biosynthesis: isotope effects associated with bicyclic olefin formation catalyzed by pinene synthases from sage (Salvia officinalis). Arch. Biochem. Biophys. 308 (1994) 477–487. [PMID: 8109978]
4.  Pyun, H.J., Wagschal, K.C., Jung, D.I., Coates, R.M. and Croteau, R. Stereochemistry of the proton elimination in the formation of (+)- and (-)-α-pinene by monoterpene cyclases from sage (Salvia officinalis). Arch. Biochem. Biophys. 308 (1994) 488–496. [PMID: 8109979]
5.  Phillips, M.A., Savage, T.J. and Croteau, R. Monoterpene synthases of loblolly pine (Pinus taeda) produce pinene isomers and enantiomers. Arch. Biochem. Biophys. 372 (1999) 197–204. [PMID: 10562434]
6.  Phillips, M.A., Wildung, M.R., Williams, D.C., Hyatt, D.C. and Croteau, R. cDNA isolation, functional expression, and characterization of (+)-α-pinene synthase and (-)-α-pinene synthase from loblolly pine (Pinus taeda): stereocontrol in pinene biosynthesis. Arch. Biochem. Biophys. 411 (2003) 267–276. [PMID: 12623076]
[EC 4.2.3.121 created 2012]
 
 
EC 2.4.1.216     Relevance: 15.3%
Accepted name: trehalose 6-phosphate phosphorylase
Reaction: α,α-trehalose 6-phosphate + phosphate = glucose 6-phosphate + β-D-glucose 1-phosphate
Other name(s): trehalose 6-phosphate:phosphate β-D-glucosyltransferase
Systematic name: α,α-trehalose 6-phosphate:phosphate β-D-glucosyltransferase
Comments: The enzyme from Lactococcus lactis is specific for trehalose 6-phosphate. Differs from EC 2.4.1.64, α,α-trehalose phosphorylase, in that trehalose is not a substrate.
References:
1.  Andersson, U., Levander, F. and Radstrom, P. Trehalose 6-phosphate phosphorylase is part of a novel metabolic pathway for trehalose utilization in Lactococcus lactis. J. Biol. Chem. 276 (2001) 42707–42713. [PMID: 11553642]
[EC 2.4.1.216 created 2001]
 
 
EC 2.4.1.312     Relevance: 15.2%
Accepted name: protein O-mannose β-1,4-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + 3-O-(α-D-mannosyl)-L-threonyl-[protein] = UDP + 3-O-[N-acetyl-β-D-glucosaminyl-(1→4)-α-D-mannosyl]-L-threonyl-[protein]
Other name(s): GTDC2 (gene name); POMGNT2
Systematic name: UDP-N-acetyl-α-D-glucosamine:α-D-mannosyl-threonyl-[protein] 4-β-N-acetyl-D-glucosaminyltransferase
Comments: The human protein is involved in the formation of a phosphorylated trisaccharide on a threonine residue of α-dystroglycan, an extracellular peripheral glycoprotein that acts as a receptor for extracellular matrix proteins containing laminin-G domains.
References:
1.  Yoshida-Moriguchi, T., Willer, T., Anderson, M.E., Venzke, D., Whyte, T., Muntoni, F., Lee, H., Nelson, S.F., Yu, L. and Campbell, K.P. SGK196 is a glycosylation-specific O-mannose kinase required for dystroglycan function. Science 341 (2013) 896–899. [PMID: 23929950]
[EC 2.4.1.312 created 2013]
 
 
EC 3.2.1.44      
Transferred entry: fucoidanase. Now EC 3.2.1.211, endo-(13)-fucoidanase and EC 3.2.1.212, endo-(14)-fucoidanase
[EC 3.2.1.44 created 1972, deleted 2020]
 
 
EC 3.6.1.54     Relevance: 15.2%
Accepted name: UDP-2,3-diacylglucosamine diphosphatase
Reaction: a UDP-2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine + H2O = a lipid X + UMP
Glossary: a lipid X = 2-N-[(3R)-3-hydroxyacyl]-3-O-[(3R)-3-hydroxyacyl]-α-D-glucosamine 1-phosphate =
2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine
Other name(s): lpxH (gene name); UDP-2,3-diacylglucosamine hydrolase; UDP-2,3-diacylglucosamine pyrophosphatase; ybbF (gene name); UDP-2,3-bis[(3R)-3-hydroxymyristoyl]-α-D-glucosamine 2,3-bis[(3R)-3-hydroxymyristoyl]-β-D-glucosaminyl 1-phosphate phosphohydrolase (incorrect); UDP-2-N,3-O-bis[(3R)-3-hydroxytetradecanoyl]-α-D-glucosamine 2-N,3-O-bis[(3R)-3-hydroxytetradecanoyl]-α-D-glucosaminyl 1-phosphate phosphohydrolase
Systematic name: UDP-2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine 2-N,3-O-bis[(3R)-3-hydroxyacyl]-α-D-glucosamine-1-phosphate phosphohydrolase
Comments: The enzyme catalyses a step in the biosynthesis of lipid A.
References:
1.  Babinski, K.J., Ribeiro, A.A. and Raetz, C.R. The Escherichia coli gene encoding the UDP-2,3-diacylglucosamine pyrophosphatase of lipid A biosynthesis. J. Biol. Chem. 277 (2002) 25937–25946. [PMID: 12000770]
2.  Babinski, K.J., Kanjilal, S.J. and Raetz, C.R. Accumulation of the lipid A precursor UDP-2,3-diacylglucosamine in an Escherichia coli mutant lacking the lpxH gene. J. Biol. Chem. 277 (2002) 25947–25956. [PMID: 12000771]
3.  Okada, C., Wakabayashi, H., Kobayashi, M., Shinoda, A., Tanaka, I. and Yao, M. Crystal structures of the UDP-diacylglucosamine pyrophosphohydrase LpxH from Pseudomonas aeruginosa. Sci. Rep. 6:32822 (2016). [PMID: 27609419]
4.  Cho, J., Lee, C.J., Zhao, J., Young, H.E. and Zhou, P. Structure of the essential Haemophilus influenzae UDP-diacylglucosamine pyrophosphohydrolase LpxH in lipid A biosynthesis. Nat Microbiol 1:16154 (2016). [PMID: 27780190]
5.  Arenas, J., Pupo, E., de Jonge, E., Perez-Ortega, J., Schaarschmidt, J., van der Ley, P. and Tommassen, J. Substrate specificity of the pyrophosphohydrolase LpxH determines the asymmetry of Bordetella pertussis lipid A. J. Biol. Chem. 294 (2019) 7982–7989. [PMID: 30926608]
[EC 3.6.1.54 created 2010, modified 2021]
 
 
EC 2.4.1.278     Relevance: 15.2%
Accepted name: 3-α-mycarosylerythronolide B desosaminyl transferase
Reaction: dTDP-D-desosamine + 3-α-L-mycarosylerythronolide B = dTDP + erythromycin D
Glossary: dTDP-D-desosamine = dTDP-3,4,6-trideoxy-3-(dimethylamino)-α-D-xylo-hexopyranose
erythromycin D = (3R,4S,5S,6R,7R,9R,11R,12S,13R,14R)-4-(2,6-dideoxy-3-C-methyl-α-L-ribo-hexopyranosyloxy)-14-ethyl-7,12-dihydroxy-6-[3,4,6-trideoxy-3-(dimethylamino)-β-D-xylo-hexopyranosyloxy]-3,5,7,9,11,13-hexamethyloxacyclotetradecane-2,10-dione
3-O-α-mycarosylerythronolide B = (3R,4S,5R,6R,7R,9R,11R,12S,13R,14R)-4-(2,6-dideoxy-3-C-methyl-α-L-ribo-hexopyranosyloxy)-14-ethyl-6,7,12-trihydroxy-3,5,7,9,11,13-hexamethyloxacyclotetradecane-2,10-dione
Other name(s): EryCIII; dTDP-3-dimethylamino-4,6-dideoxy-α-D-glucopyranose:3-α-mycarosylerythronolide B 3-dimethylamino-4,6-dideoxy-α-D-glucosyltransferase
Systematic name: dTDP-3-dimethylamino-3,4,6-trideoxy-α-D-glucopyranose:3-α-mycarosylerythronolide B 3-dimethylamino-3,4,6-trideoxy-β-D-glucosyltransferase
Comments: The enzyme is involved in erythromycin biosynthesis.
References:
1.  Yuan, Y., Chung, H.S., Leimkuhler, C., Walsh, C.T., Kahne, D. and Walker, S. In vitro reconstitution of EryCIII activity for the preparation of unnatural macrolides. J. Am. Chem. Soc. 127 (2005) 14128–14129. [PMID: 16218575]
2.  Lee, H.Y., Chung, H.S., Hang, C., Khosla, C., Walsh, C.T., Kahne, D. and Walker, S. Reconstitution and characterization of a new desosaminyl transferase, EryCIII, from the erythromycin biosynthetic pathway. J. Am. Chem. Soc. 126 (2004) 9924–9925. [PMID: 15303858]
3.  Moncrieffe, M.C., Fernandez, M.J., Spiteller, D., Matsumura, H., Gay, N.J., Luisi, B.F. and Leadlay, P.F. Structure of the glycosyltransferase EryCIII in complex with its activating P450 homologue EryCII. J. Mol. Biol. 415 (2012) 92–101. [PMID: 22056329]
[EC 2.4.1.278 created 2012, modified 2014]
 
 
EC 2.4.99.1      
Transferred entry: β-galactoside α-(2,6)-sialyltransferase. Now EC 2.4.3.1, β-galactoside α-(2,6)-sialyltransferase
[EC 2.4.99.1 created 1972, modified 1976, modified 1986, modified 2017 (EC 2.4.99.11 created 1992, incorporated 2017), deleted 2022]
 
 
EC 2.4.3.1     Relevance: 15.2%
Accepted name: β-galactoside α-(2,6)-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + β-D-galactosyl-R = CMP + N-acetyl-α-neuraminyl-(2→6)-β-D-galactosyl-R
Other name(s): ST6Gal-I; CMP-N-acetylneuraminate:β-D-galactosyl-1,4-N-acetyl-β-D-glucosamine α-2,6-N-acetylneuraminyltransferase; lactosylceramide α-2,6-N-sialyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosamine α-(2→6)-N-acetylneuraminyltransferase; β-galactoside α-2,6-sialyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:β-D-galactoside α-(2→6)-N-acetylneuraminyltransferase (configuration-inverting)
Comments: The enzyme acts on the terminal non-reducing β-D-galactosyl residue of the oligosaccharide moiety of glycoproteins and glycolipids.
References:
1.  Spiro, M.H. and Spiro, R.G. Glycoprotein biosynthesis: studies on thyroglobulin. Thyroid sialyltransferase. J. Biol. Chem. 243 (1968) 6520–6528. [PMID: 5726897]
2.  Hickman, J., Ashwell, G., Morell, A.G., van der Hamer, C.J.A. and Scheinberg, I.H. Physical and chemical studies on ceruloplasmin. 8. Preparation of N-acetylneuraminic acid-1-14C-labeled ceruloplasmin. J. Biol. Chem. 245 (1970) 759–766. [PMID: 4313609]
3.  Bartholomew, B.A., Jourdian, G.W. and Roseman, S. The sialic acids. XV. Transfer of sialic acid to glycoproteins by a sialyltransferase from colostrum. J. Biol. Chem. 248 (1973) 5751–5762. [PMID: 4723915]
4.  Paulson, J.C., Beranek, W.E. and Hill, R.L. Purification of a sialyltransferase from bovine colostrum by affinity chromatography on CDP-agarose. J. Biol. Chem. 252 (1977) 2356–2362. [PMID: 849932]
5.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
6.  Albarracin, I., Lassaga, F.E. and Caputto, R. Purification and characterization of an endogenous inhibitor of the sialyltransferase CMP-N-acetylneuraminate: lactosylceramide α2,6-N-acetylneuraminyltransferase (EC 2.4.99.-). Biochem. J. 254 (1988) 559–565. [PMID: 2460092]
[EC 2.4.3.1 created 1972 as EC 2.4.99.1, modified 1976, modified 1986, modified 2017 (EC 2.4.99.11 created 1992, incorporated 2016), modified 2017, transferred 2021 to EC 2.4.3.1]
 
 
EC 3.2.1.113     Relevance: 15.2%
Accepted name: mannosyl-oligosaccharide 1,2-α-mannosidase
Reaction: (1) Man9GlcNAc2-[protein] + 4 H2O = Man5GlcNAc2-[protein] + 4 β-D-mannopyranose (overall reaction)
(1a) Man9GlcNAc2-[protein] + H2O = Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,2) + β-D-mannopyranose
(1b) Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,2) + H2O = Man7GlcNAc2-[protein] (isomer 7A1,2,3B2) + β-D-mannopyranose
(1c) Man7GlcNAc2-[protein] (isomer 7A1,2,3B2) + H2O = Man6GlcNAc2-[protein] (isomer 6A1,2B2) + β-D-mannopyranose
(1d) Man6GlcNAc2-[protein] (isomer 6A1,2B2) + H2O = Man5GlcNAc2-[protein] + β-D-mannopyranose
(2) Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) + 3 H2O = Man5GlcNAc2-[protein] + 3 β-D-mannopyranose (overall reaction)
(2a) Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) + H2O = Man7GlcNAc2-[protein] (isomer 7A1,2,3B1) + β-D-mannopyranose
(2b) Man7GlcNAc2-[protein] (isomer 7A1,2,3B1) + H2O = Man6GlcNAc2-[protein] (isomer 6A1,2,3) + β-D-mannopyranose
(2c) Man6GlcNAc2-[protein] (isomer 6A1,2,3) + H2O = Man5GlcNAc2-[protein] + β-D-mannopyranose
Glossary: Man9GlcNAc2-[protein] = [α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-{α-D-Man-(1→2)-α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)}-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc]-N-Asn-[protein]
Man8GlcNAc2-[protein] (isomer 8A1,2,3B1,3) = [α-D-Man-(1→2)-α-D-Man-(1→2)-α-D-Man-(1→3)-{α-D-Man-(1→3)-[α-D-Man-(1→2)-α-D-Man-(1→6)]-α-D-Man-(1→6)}-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc]-N-Asn-[protein]
Man5GlcNAc2-[protein] = [α-D-Man-(1→3)-{α-D-Man-(1→3)-[α-D-Man-(1→6)]-α-D-Man-(1→6)}-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc]-N-Asn-[protein]
Other name(s): mannosidase 1A; mannosidase 1B; 1,2-α-mannosidase; exo-α-1,2-mannanase; mannose-9 processing α-mannosidase; glycoprotein processing mannosidase I; mannosidase I; Man9-mannosidase; ManI; 1,2-α-mannosyl-oligosaccharide α-D-mannohydrolase; MAN1A1 (gene name); MAN1A2 (gene name); MAN1C1 (gene name); 2-α-mannosyl-oligosaccharide α-D-mannohydrolase
Systematic name: Man9GlcNAc2-[protein] α-2-mannohydrolase (configuration-inverting)
Comments: This family of mammalian enzymes, located in the Golgi system, participates in the maturation process of N-glycans that leads to formation of hybrid and complex structures. The enzymes catalyse the hydrolysis of the four (1→2)-linked α-D-mannose residues from the Man9GlcNAc2 oligosaccharide attached to target proteins as described in reaction (1). Alternatively, the enzymes act on the Man8GlcNAc2 isomer formed by EC 3.2.1.209, endoplasmic reticulum Man9GlcNAc2 1,2-α-mannosidase, as described in reaction (2). The enzymes are type II membrane proteins, require Ca2+, and use an inverting mechanism. While all three human enzymes can catalyse the reactions listed here, some of the enzymes can additionally catalyse hydrolysis in an alternative order, generating additional isomeric intermediates, although the final product is the same. The names of the isomers listed here are based on a nomenclature system proposed by Prien et al [7].
References:
1.  Tabas, I. and Kornfeld, S. Purification and characterization of a rat liver Golgi α-mannosidase capable of processing asparagine-linked oligosaccharides. J. Biol. Chem. 254 (1979) 11655–11663. [PMID: 500665]
2.  Tulsiani, D.R.P., Hubbard, S.C., Robbins, P.W. and Touster, O. α-D-Mannosidases of rat liver Golgi membranes. Mannosidase II is the GlcNAcMAN5-cleaving enzyme in glycoprotein biosynthesis and mannosidases IA and IB are the enzymes converting Man9 precursors to Man5 intermediates. J. Biol. Chem. 257 (1982) 3660–3668. [PMID: 7061502]
3.  Bieberich, E. and Bause, E. Man9-mannosidase from human kidney is expressed in COS cells as a Golgi-resident type II transmembrane N-glycoprotein. Eur. J. Biochem. 233 (1995) 644–649. [PMID: 7588811]
4.  Tremblay, L.O., Campbell Dyke, N. and Herscovics, A. Molecular cloning, chromosomal mapping and tissue-specific expression of a novel human α1,2-mannosidase gene involved in N-glycan maturation. Glycobiology 8 (1998) 585–595. [PMID: 9592125]
5.  Lal, A., Pang, P., Kalelkar, S., Romero, P.A., Herscovics, A. and Moremen, K.W. Substrate specificities of recombinant murine Golgi α1,2-mannosidases IA and IB and comparison with endoplasmic reticulum and Golgi processing α1,2-mannosidases. Glycobiology 8 (1998) 981–995. [PMID: 9719679]
6.  Tremblay, L.O. and Herscovics, A. Characterization of a cDNA encoding a novel human Golgi α 1, 2-mannosidase (IC) involved in N-glycan biosynthesis. J. Biol. Chem. 275 (2000) 31655–31660. [PMID: 10915796]
7.  Prien, J.M., Ashline, D.J., Lapadula, A.J., Zhang, H. and Reinhold, V.N. The high mannose glycans from bovine ribonuclease B isomer characterization by ion trap MS. J. Am. Soc. Mass Spectrom. 20 (2009) 539–556. [PMID: 19181540]
[EC 3.2.1.113 created 1986, modified 2019]
 
 
EC 2.6.1.106     Relevance: 15.2%
Accepted name: dTDP-3-amino-3,4,6-trideoxy-α-D-glucose transaminase
Reaction: dTDP-3-amino-3,4,6-trideoxy-α-D-glucose + 2-oxoglutarate = dTDP-3-dehydro-4,6-deoxy-α-D-glucose + L-glutamate
Glossary: dTDP-α-D-desosamine = dTDP-3-(dimethylamino)-3,4,6-trideoxy-α-D-glucose
Other name(s): desV (gene name); megDII (gene name); eryCI (gene name)
Systematic name: dTDP-3-amino-3,4,6-trideoxy-α-D-glucose:2-oxoglutarate aminotransferase
Comments: A pyridoxal-phosphate protein. The enzyme is involved in the biosynthesis of dTDP-α-D-desosamine, a sugar found in several bacterial macrolide antibiotics including erythromycin, megalomicin A, mycinamicin II, and oleandomycin. The reaction occurs in the reverse direction.
References:
1.  Burgie, E.S., Thoden, J.B. and Holden, H.M. Molecular architecture of DesV from Streptomyces venezuelae: a PLP-dependent transaminase involved in the biosynthesis of the unusual sugar desosamine. Protein Sci. 16 (2007) 887–896. [PMID: 17456741]
[EC 2.6.1.106 created 2014]
 
 
EC 2.4.1.88     Relevance: 15.2%
Accepted name: globoside α-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-α-D-galactosaminyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): uridine diphosphoacetylgalactosamine-globoside α-acetylgalactosaminyltransferase; Forssman synthase; globoside acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetyl-D-galactosaminyl-1,3-D-galactosyl-1,4-D-galactosyl-1,4-D-glucosylceramide α-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetyl-D-galactosaminyl-(1→3)-D-galactosyl-(1→4)-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide α-N-acetyl-D-galactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide α-N-acetyl-D-galactosaminyltransferase
References:
1.  Kijimoto, S., Ishibashi, T. and Makita, A. Biosynthesis of Forssman hapten from globoside by α-N-acetylgalactosaminyltransferase of guinea pig tissues. Biochem. Biophys. Res. Commun. 56 (1974) 177–184. [PMID: 4823436]
[EC 2.4.1.88 created 1976]
 
 
EC 2.4.1.372     Relevance: 15.1%
Accepted name: mutansucrase
Reaction: sucrose + [(1→3)-α-D-glucosyl]n = D-fructose + [(1→3)-α-D-glucosyl]n+1
Other name(s): gtfJ (gene name)
Systematic name: sucrose:(1→3)-α-D-glucan 3-α-D-glucosyltransferase
Comments: The glucansucrases transfer a D-glucosyl residue from sucrose to a glucan chain. They are classified based on the linkage by which they attach the transferred residue. In some cases, in which the enzyme forms more than one linkage type, classification relies on the relative proportion of the linkages that are generated. This enzyme extends the glucan chain by an α(1→3) linkage.
References:
1.  Simpson, C.L., Cheetham, N.W., Giffard, P.M. and Jacques, N.A. Four glucosyltransferases, GtfJ, GtfK, GtfL and GtfM, from Streptococcus salivarius ATCC 25975. Microbiology 141 (1995) 1451–1460. [PMID: 7545511]
2.  Puanglek, S., Kimura, S., Enomoto-Rogers, Y., Kabe, T., Yoshida, M., Wada, M. and Iwata, T. In vitro synthesis of linear α-1,3-glucan and chemical modification to ester derivatives exhibiting outstanding thermal properties. Sci. Rep. 6:30479 (2016). [PMID: 27469976]
[EC 2.4.1.372 created 2019]
 
 
EC 1.1.1.374     Relevance: 15.1%
Accepted name: UDP-N-acetylglucosamine 3-dehydrogenase
Reaction: UDP-N-acetyl-α-D-glucosamine + NAD+ = UDP-2-acetamido-3-dehydro-2-deoxy-α-D-glucopyranose + NADH + H+
Systematic name: UDP-N-acetyl-α-D-glucosamine:NAD+ 3-oxidoreductase
Comments: The enzyme from the archaeon Methanococcus maripaludis is activated by KCl (200 mM).
References:
1.  Namboori, S.C. and Graham, D.E. Enzymatic analysis of uridine diphosphate N-acetyl-D-glucosamine. Anal. Biochem. 381 (2008) 94–100. [PMID: 18634748]
[EC 1.1.1.374 created 2014]
 
 
EC 2.4.99.4      
Transferred entry: β-galactoside α-2,3-sialyltransferase. Now EC 2.4.3.4, β-galactoside α-2,3-sialyltransferase
[EC 2.4.99.4 created 1984, modified 1986, deleted 2022]
 
 
EC 1.1.1.136     Relevance: 15.1%
Accepted name: UDP-N-acetylglucosamine 6-dehydrogenase
Reaction: UDP-N-acetyl-α-D-glucosamine + 2 NAD+ + H2O = UDP-2-acetamido-2-deoxy-α-D-glucuronate + 2 NADH + 2 H+
Other name(s): uridine diphosphoacetylglucosamine dehydrogenase; UDP-acetylglucosamine dehydrogenase; UDP-2-acetamido-2-deoxy-D-glucose:NAD oxidoreductase; UDP-GlcNAc dehydrogenase; WbpA; WbpO
Systematic name: UDP-N-acetyl-α-D-glucosamine:NAD+ 6-oxidoreductase
Comments: This enzyme participates in the biosynthetic pathway for UDP-α-D-ManNAc3NAcA (UDP-2,3-diacetamido-2,3-dideoxy-α-D-mannuronic acid), an important precursor of B-band lipopolysaccharide.
References:
1.  Fan, D.-F., John, C.E., Zalitis, J. and Feingold, D.S. UDPacetylglucosamine dehydrogenase from Achromobacter georgiopolitanum. Arch. Biochem. Biophys. 135 (1969) 45–49. [PMID: 4312076]
2.  Miller, W.L., Wenzel, C.Q., Daniels, C., Larocque, S., Brisson, J.R. and Lam, J.S. Biochemical characterization of WbpA, a UDP-N-acetyl-D-glucosamine 6-dehydrogenase involved in O-antigen biosynthesis in Pseudomonas aeruginosa PAO1. J. Biol. Chem. 279 (2004) 37551–37558. [PMID: 15226302]
[EC 1.1.1.136 created 1972, modified 2012]
 
 
EC 2.4.1.313     Relevance: 15.1%
Accepted name: protein O-mannose β-1,3-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + 3-O-[N-acetyl-β-D-glucosaminyl-(1→4)-α-D-mannosyl]-L-threonyl-[protein] = UDP + 3-O-[N-acetyl-β-D-galactosaminyl-(1→3)-N-acetyl-β-D-glucosaminyl-(1→4)-α-D-mannosyl]-L-threonyl-[protein]
Other name(s): B3GALNT2
Systematic name: UDP-N-acetyl-α-D-galactosamine:N-acetyl-β-D-glucosaminyl-(1→4)-α-D-mannosyl-threonyl-[protein] 3-β-N-acetyl-D-galactosaminyltransferase
Comments: The human protein is specific for UDP-N-acetyl-α-D-galactosamine as donor [1]. The enzyme is involved in the formation of a phosphorylated trisaccharide on a threonine residue of α-dystroglycan, an extracellular peripheral glycoprotein that acts as a receptor for extracellular matrix proteins containing laminin-G domains.
References:
1.  Hiruma, T., Togayachi, A., Okamura, K., Sato, T., Kikuchi, N., Kwon, Y.D., Nakamura, A., Fujimura, K., Gotoh, M., Tachibana, K., Ishizuka, Y., Noce, T., Nakanishi, H. and Narimatsu, H. A novel human β1,3-N-acetylgalactosaminyltransferase that synthesizes a unique carbohydrate structure, GalNAcβ1-3GlcNAc. J. Biol. Chem. 279 (2004) 14087–14095. [PMID: 14724282]
2.  Yoshida-Moriguchi, T., Willer, T., Anderson, M.E., Venzke, D., Whyte, T., Muntoni, F., Lee, H., Nelson, S.F., Yu, L. and Campbell, K.P. SGK196 is a glycosylation-specific O-mannose kinase required for dystroglycan function. Science 341 (2013) 896–899. [PMID: 23929950]
[EC 2.4.1.313 created 2013]
 
 
EC 4.2.2.24     Relevance: 15.1%
Accepted name: rhamnogalacturonan exolyase
Reaction: Exotype eliminative cleavage of α-L-rhamnopyranosyl-(1→4)-α-D-galactopyranosyluronic acid bonds of rhamnogalacturonan I oligosaccharides containing α-L-rhamnopyranose at the reducing end and 4-deoxy-4,5-unsaturated D-galactopyranosyluronic acid at the non-reducing end. The products are the disaccharide 2-O-(4-deoxy-β-L-threo-hex-4-enopyranuronosyl)-α-L-rhamnopyranose and the shortened rhamnogalacturonan oligosaccharide containing one 4-deoxy-4,5-unsaturated D-galactopyranosyluronic acid at the non-reducing end.
Glossary: 6-deoxy-2-O-(4-deoxy-β-L-threo-hex-4-enopyranuronosyl)-α-L-mannopyranose = 2-O-(4-deoxy-β-L-threo-hex-4-enopyranuronosyl)-α-L-rhamnopyranose
Other name(s): YesX
Systematic name: α-L-rhamnopyranosyl-(1→4)-α-D-galactopyranosyluronate exolyase
Comments: The enzyme is part of the degradation system for rhamnogalacturonan I in Bacillus subtilis strain 168.
References:
1.  Ochiai, A., Itoh, T., Mikami, B., Hashimoto, W. and Murata, K. Structural determinants responsible for substrate recognition and mode of action in family 11 polysaccharide lyases. J. Biol. Chem. 284 (2009) 10181–10189. [PMID: 19193638]
2.  Ochiai, A., Itoh, T., Kawamata, A., Hashimoto, W. and Murata, K. Plant cell wall degradation by saprophytic Bacillus subtilis strains: gene clusters responsible for rhamnogalacturonan depolymerization. Appl. Environ. Microbiol. 73 (2007) 3803–3813. [PMID: 17449691]
[EC 4.2.2.24 created 2011]
 
 
EC 3.2.1.168     Relevance: 15.1%
Accepted name: hesperidin 6-O-α-L-rhamnosyl-β-D-glucosidase
Reaction: hesperidin + H2O = hesperetin + rutinose
Glossary: hesperetin = 5,7,3′-trihydroxy-4′-methoxyflavanone
hesperidin = hesperetin 7-(6-O-α-L-rhamnopyranosyl-β-D-glucopyranoside)
rutinose = 6-O-α-L-rhamnopyranosyl-D-glucose
Systematic name: hesperetin 7-(6-O-α-L-rhamnopyranosyl-β-D-glucopyranoside) 6-O-α-rhamnopyranosyl-β-glucohydrolase
Comments: The enzyme exhibits high specificity towards 7-O-linked flavonoid β-rutinosides.
References:
1.  Mazzaferro, L., Piñuel, L., Minig, M. and Breccia, J.D. Extracellular monoenzyme deglycosylation system of 7-O-linked flavonoid β-rutinosides and its disaccharide transglycosylation activity from Stilbella fimetaria. Arch. Microbiol. 192 (2010) 383–393. [PMID: 20358178]
2.  Mazzaferro, L., Piñuel, L., Minig, M. and Breccia, J.D. Erratum to: Extracellular monoenzyme deglycosylation system of 7-O-linked flavonoid β-rutinosides and its disaccharide transglycosylation activity from Stilbella fimetaria. Arch. Microbiol. 193 (2011) 461.
[EC 3.2.1.168 created 2011]
 
 
EC 2.4.1.332     Relevance: 15.1%
Accepted name: 1,2-α-glucosylglycerol phosphorylase
Reaction: 2-O-α-D-glucopyranosyl-glycerol + phosphate = β-D-glucose 1-phosphate + glycerol
Other name(s): 2-O-α-D-glucopyranosylglycerol phosphorylase
Systematic name: 2-O-α-D-glucopyranosyl-glycerol:phosphate β-D-glucosyltransferase
Comments: The enzyme has been isolated from the bacterium Bacillus selenitireducens. In the absence of glycerol the enzyme produces α-D-glucopyranose and phosphate from β-D-glucopyranose 1-phosphate. In this reaction the glucosyl residue is transferred to a water molecule with an inversion of the anomeric conformation.
References:
1.  Nihira, T., Saito, Y., Ohtsubo, K., Nakai, H. and Kitaoka, M. 2-O-α-D-glucosylglycerol phosphorylase from Bacillus selenitireducens MLS10 possessing hydrolytic activity on β-D-glucose 1-phosphate. PLoS One 9:e86548 (2014). [PMID: 24466148]
2.  Touhara, K.K., Nihira, T., Kitaoka, M., Nakai, H. and Fushinobu, S. Structural basis for reversible phosphorolysis and hydrolysis reactions of 2-O-α-glucosylglycerol phosphorylase. J. Biol. Chem. 289 (2014) 18067–18075. [PMID: 24828502]
[EC 2.4.1.332 created 2014]
 
 
EC 2.4.1.15     Relevance: 15.1%
Accepted name: α,α-trehalose-phosphate synthase (UDP-forming)
Reaction: UDP-α-D-glucose + D-glucose 6-phosphate = UDP + α,α-trehalose 6-phosphate
Other name(s): UDP-glucose—glucose-phosphate glucosyltransferase; trehalosephosphate-UDP glucosyltransferase; UDP-glucose-glucose-phosphate glucosyltransferase; α,α-trehalose phosphate synthase (UDP-forming); phosphotrehalose-uridine diphosphate transglucosylase; trehalose 6-phosphate synthase; trehalose 6-phosphate synthetase; trehalose phosphate synthase; trehalose phosphate synthetase; trehalose phosphate-uridine diphosphate glucosyltransferase; trehalose-P synthetase; transglucosylase; uridine diphosphoglucose phosphate glucosyltransferase; UDP-glucose:D-glucose-6-phosphate 1-α-D-glucosyltransferase
Systematic name: UDP-α-D-glucose:D-glucose-6-phosphate 1-α-D-glucosyltransferase (configuration-retaining)
Comments: See also EC 2.4.1.36 [α,α-trehalose-phosphate synthase (GDP-forming)].
References:
1.  Cabib, E. and Leloir, L.F. The biosynthesis of trehalose phosphate. J. Biol. Chem. 231 (1958) 259–275. [PMID: 13538966]
2.  Candy, D.J. and Kilby, B.A. The biosynthesis of trehalose in the locust fat body. Biochem. J. 78 (1961) 531–536. [PMID: 13690400]
3.  Lornitzo, F.A. and Goldman, D.S. Purification and properties of the transglucosylase inhibitor of Mycobacterium tuberculosis. J. Biol. Chem. 239 (1964) 2730–2734. [PMID: 14216421]
4.  Murphy, T.A. and Wyatt, G.R. The enzymes of glycogen and trehalose synthesis in silk moth fat body. J. Biol. Chem. 240 (1965) 1500–1508. [PMID: 14285483]
[EC 2.4.1.15 created 1961]
 
 
EC 4.2.3.85     Relevance: 15%
Accepted name: α-eudesmol synthase
Reaction: (2E,6E)-farnesyl diphosphate + H2O = α-eudesmol + diphosphate
Glossary: (-)-α-eudesmol = 2-[(2R,4aR,8aR)-4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl]propan-2-ol
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase (α-eudesmol-forming)
Comments: The recombinant enzyme from ginger (Zingiber zerumbet) gives 62.6% β-eudesmol, 16.8% 10-epi-γ-eudesmol, 10% α-eudesmol, and 5.6% aristolene. cf. EC 4.2.3.68 (β-eudesmol synthase) and EC 4.2.3.84 (10-epi-γ-eudesmol synthase)
References:
1.  Yu, F., Harada, H., Yamasaki, K., Okamoto, S., Hirase, S., Tanaka, Y., Misawa, N. and Utsumi, R. Isolation and functional characterization of a β-eudesmol synthase, a new sesquiterpene synthase from Zingiber zerumbet Smith. FEBS Lett. 582 (2008) 565–572. [PMID: 18242187]
[EC 4.2.3.85 created 2011]
 
 
EC 3.2.1.11     Relevance: 15%
Accepted name: dextranase
Reaction: Endohydrolysis of (1→6)-α-D-glucosidic linkages in dextran
Other name(s): dextran hydrolase; endodextranase; dextranase DL 2; DL 2; endo-dextranase; α-D-1,6-glucan-6-glucanohydrolase; 1,6-α-D-glucan 6-glucanohydrolase
Systematic name: 6-α-D-glucan 6-glucanohydrolase
References:
1.  Bailey, R.W. and Clarke, R.T.J. A bacterial dextranase. Biochem. J. 72 (1959) 49–54. [PMID: 13651134]
2.  Deuel, H. and Stutz, E. Pectic substances and pectic enzymes. Adv. Enzymol. Relat. Areas Mol. Biol. 20 (1958) 341–382. [PMID: 13605988]
3.  Fischer, E.H. and Stein, E.A. Cleavage of O- and S-glycosidic bonds (survey). In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 4, Academic Press, New York, 1960, pp. 301–312.
4.  Rozenfel'd, E.L. and Lukomskaya, I.S. [The hydrolysis of 1:6 bonds of dextran by animal tissues.] Biokhimiya 21 (1956) 412–415. [PMID: 13363992] (in Russian)
[EC 3.2.1.11 created 1961]
 
 
EC 2.4.1.67     Relevance: 15%
Accepted name: galactinol—raffinose galactosyltransferase
Reaction: α-D-galactosyl-(1→3)-1D-myo-inositol + raffinose = myo-inositol + stachyose
Glossary: raffinose = β-D-fructofuranosyl α-D-galactopyranosyl-(1→6)-α-D-glucopyranoside
Other name(s): galactinol-raffinose galactosyltransferase; stachyose synthetase; α-D-galactosyl-(1→3)-myo-inositol:raffinose galactosyltransferase
Systematic name: α-D-galactosyl-(1→3)-1D-myo-inositol:raffinose galactosyltransferase
Comments: This enzyme also catalyses galactosyl transfer from stachyose to raffinose (shown by labelling) [4]. For synthesis of the substrate, see EC 2.4.1.123, inositol 3-α-galactosyltransferase. See also EC 2.4.1.82, galactinol—sucrose galactosyltransferase.
References:
1.  Tanner, W. Die Biosynthese der Stachyose. Ber. Dtsch. Bot. Ges. 80 (1967) 111.
2.  Tanner, W. and Kandler, O. Myo-inositol, a cofactor in the biosynthesis of stachyose. Eur. J. Biochem. 4 (1968) 233–239. [PMID: 5655499]
3.  Lehle, L. and Tanner, W. The function of myo-inositol in the biosynthesis of raffinose. Purification and characterization of galactinol:sucrose 6-galactosyltransferase from Vicia faba seeds. Eur. J. Biochem. 38 (1973) 103–110. [PMID: 4774118]
4.  Kandler, O. and Hopf, H. Occurrence, metabolism and function of oligosaccharides. In: Preiss, J. (Ed.), The Biochemistry of Plant, vol. 3, Academic Press, New York, 1980, pp. 221–270.
[EC 2.4.1.67 created 1972, modified 2003]
 
 
EC 4.2.3.169     Relevance: 15%
Accepted name: 7-epi-α-eudesmol synthase
Reaction: (2E,6E)-farnesyl diphosphate + H2O = 7-epi-α-eudesmol + diphosphate
Glossary: 7-epi-α-eudesmol = 2-[(2S,4aR,8aR)-4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl]propan-2-ol
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase (cyclizing, 7-epi-α-eudesmol-forming)
Comments: The enzyme, found in the bacterium Streptomyces viridochromogenes, is specific for (2E,6E)-farnesyl diphosphate.
References:
1.  Rabe, P., Schmitz, T. and Dickschat, J.S. Mechanistic investigations on six bacterial terpene cyclases. Beilstein J. Org. Chem. 12 (2016) 1839–1850. [PMID: 27829890]
[EC 4.2.3.169 created 2017]
 
 
EC 2.4.1.68     Relevance: 15%
Accepted name: glycoprotein 6-α-L-fucosyltransferase
Reaction: GDP-β-L-fucose + N4-{β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-L-asparaginyl-[protein] = GDP + N4-{β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-[α-L-Fuc-(1→6)]-β-D-GlcNAc}-L-asparaginyl-[protein]
Other name(s): GDP-fucose—glycoprotein fucosyltransferase; GDP-L-Fuc:N-acetyl-β-D-glucosaminide α1→6fucosyltransferase; GDP-L-fucose-glycoprotein fucosyltransferase; glycoprotein fucosyltransferase; guanosine diphosphofucose-glycoprotein fucosyltransferase; GDP-L-fucose:glycoprotein (L-fucose to asparagine-linked N-acetylglucosamine of 4-N-{N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→6)]-β-D-mannosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-β-D-glucosaminyl}asparagine) 6-α-L-fucosyltransferase; FucT; GDP-L-fucose:glycoprotein (L-fucose to asparagine-linked N-acetylglucosamine of N4-{N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→6)]-β-D-mannosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-β-D-glucosaminyl}asparagine) 6-α-L-fucosyltransferase; GDP-β-L-fucose:glycoprotein (L-fucose to asparagine-linked N-acetylglucosamine of N4-{N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→6)]-β-D-mannosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-β-D-glucosaminyl}asparagine) 6-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:N4-{β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-L-asparaginyl-[protein] 6-α-L-fucosyltransferase (configuration-inverting)
Comments: This enzyme catalyses a reaction similar to that of EC 2.4.1.214, glycoprotein 3-α-L-fucosyltransferase, but transfers the L-fucosyl group from GDP-β-L-fucose to form an α1,6-linkage rather than an α1,3-linkage.
References:
1.  Longmore, G.D. and Schachter, H. Product-identification and substrate-specificity studies of the GDP-L-fucose:2-acetamido-2-deoxy-β-D-glucoside (Fuc → Asn-linked GlcNAc) 6-α-L-fucosyltransferase in a Golgi-rich fraction from porcine liver. Carbohydr. Res. 100 (1982) 365–392. [PMID: 7083256]
2.  Voynow, J.A., Scanlin, T.F. and Glick, M.C. A quantitative method for GDP-L-Fuc:N-acetyl-β-D-glucosaminide α1→6fucosyltransferase activity with lectin affinity chromatography. Anal. Biochem. 168 (1988) 367–373. [PMID: 3364733]
3.  Uozumi, N., Yanagidani, S., Miyoshi, E., Ihara, Y., Sakuma, T., Gao, C.-X., Teshima, T., Fujii, S., Shiba, T. and Taniguchi, N. Purification and cDNA cloning of porcine brain GDP-L-Fuc:N-acetyl-β-D-glucosaminide α1→6fucosyltransferase. J. Biol. Chem. 271 (1996) 27810–27817. [PMID: 8910378]
[EC 2.4.1.68 created 1972, modified 2002]
 
 
EC 2.7.7.83     Relevance: 15%
Accepted name: UDP-N-acetylgalactosamine diphosphorylase
Reaction: UTP + N-acetyl-α-D-galactosamine 1-phosphate = diphosphate + UDP-N-acetyl-α-D-galactosamine
Systematic name: UTP:N-acetyl-α-D-galactosamine-1-phosphate uridylyltransferase
Comments: The enzyme from plants and animals also has activity toward N-acetyl-α-D-glucosamine 1-phosphate (cf. EC 2.7.7.23, UDP-N-acetylglucosamine diphosphorylase) [1,2].
References:
1.  Wang-Gillam, A., Pastuszak, I. and Elbein, A.D. A 17-amino acid insert changes UDP-N-acetylhexosamine pyrophosphorylase specificity from UDP-GalNAc to UDP-GlcNAc. J. Biol. Chem. 273 (1998) 27055–27057. [PMID: 9765219]
2.  Peneff, C., Ferrari, P., Charrier, V., Taburet, Y., Monnier, C., Zamboni, V., Winter, J., Harnois, M., Fassy, F. and Bourne, Y. Crystal structures of two human pyrophosphorylase isoforms in complexes with UDPGlc(Gal)NAc: role of the alternatively spliced insert in the enzyme oligomeric assembly and active site architecture. EMBO J. 20 (2001) 6191–6202. [PMID: 11707391]
[EC 2.7.7.83 created 2012]
 
 
EC 4.7.1.1     Relevance: 15%
Accepted name: α-D-ribose 1-methylphosphonate 5-phosphate C-P-lyase
Reaction: α-D-ribose 1-methylphosphonate 5-phosphate + S-adenosyl-L-methionine + reduced electron acceptor = α-D-ribose 1,2-cyclic phosphate 5-phosphate + methane + L-methionine + 5′-deoxyadenosine + oxidized electron acceptor
Other name(s): phnJ (gene name)
Systematic name: α-D-ribose-1-methylphosphonate-5-phosphate C-P-lyase (methane-forming)
Comments: This radical SAM (AdoMet) enzyme is part of the C-P lyase complex, which is responsible for processing phophonates into usable phosphate. Contains an [4Fe-4S] cluster. The enzyme from the bacterium Escherichia coli can act on additional α-D-ribose phosphonate substrates with different substituents attached to the phosphonate phosphorus (e.g. α-D-ribose-1-[N-(phosphonomethyl)glycine]-5-phosphate and α-D-ribose-1-(2-N-acetamidomethylphosphonate)-5-phosphate).
References:
1.  Kamat, S.S., Williams, H.J. and Raushel, F.M. Intermediates in the transformation of phosphonates to phosphate by bacteria. Nature 480 (2011) 570–573. [PMID: 22089136]
2.  Jochimsen, B., Lolle, S., McSorley, F.R., Nabi, M., Stougaard, J., Zechel, D.L. and Hove-Jensen, B. Five phosphonate operon gene products as components of a multi-subunit complex of the carbon-phosphorus lyase pathway. Proc. Natl. Acad. Sci. USA 108 (2011) 11393–11398. [PMID: 21705661]
3.  Zhang, Q. and van der Donk, W.A. Answers to the carbon-phosphorus lyase conundrum. ChemBioChem 13 (2012) 627–629. [PMID: 22334536]
[EC 4.7.1.1 created 2013, modified 2016]
 
 
EC 2.4.1.356     Relevance: 15%
Accepted name: glucosyl-dolichyl phosphate glucuronosyltransferase
Reaction: UDP-α-D-glucuronate + an archaeal dolichyl α-D-glucosyl phosphate = UDP + an archaeal dolichyl β-D-glucuronosyl-(1→4)-α-D-glucosyl phosphate
Other name(s): aglG (gene name)
Systematic name: UDP-α-D-glucuronate:dolichyl phosphate glucuronosyltransferase (configuration-inverting)
Comments: The enzyme, characterized from the halophilic archaeon Haloferax volcanii, participates in the protein N-glycosylation pathway. Dolichol used by archaea is different from that used by eukaryotes. It is much shorter (C55-C60) and is α,ω-saturated. However, in vitro the enzyme was also able to act on a substrate with an unsaturated end.
References:
1.  Yurist-Doutsch, S., Abu-Qarn, M., Battaglia, F., Morris, H.R., Hitchen, P.G., Dell, A. and Eichler, J. aglF, aglG and aglI, novel members of a gene island involved in the N-glycosylation of the Haloferax volcanii S-layer glycoprotein. Mol. Microbiol. 69 (2008) 1234–1245. [PMID: 18631242]
2.  Elharar, Y., Podilapu, A.R., Guan, Z., Kulkarni, S.S. and Eichler, J. Assembling glycan-charged dolichol phosphates: chemoenzymatic synthesis of a Haloferax volcanii N-glycosylation pathway intermediate. Bioconjugate Chem. 28 (2017) 2461–2470. [PMID: 28809486]
[EC 2.4.1.356 created 2018]
 
 
EC 3.6.1.63     Relevance: 14.9%
Accepted name: α-D-ribose 1-methylphosphonate 5-triphosphate diphosphatase
Reaction: α-D-ribose 1-methylphosphonate 5-triphosphate + H2O = α-D-ribose 1-methylphosphonate 5-phosphate + diphosphate
Other name(s): phnM (gene name)
Systematic name: α-D-ribose-1-methylphosphonate-5-triphosphate diphosphohydrolase
Comments: Isolated from the bacterium Escherichia coli.
References:
1.  Kamat, S.S., Williams, H.J. and Raushel, F.M. Intermediates in the transformation of phosphonates to phosphate by bacteria. Nature 480 (2011) 570–573. [PMID: 22089136]
[EC 3.6.1.63 created 2012]
 
 
EC 2.7.8.18     Relevance: 14.9%
Accepted name: UDP-galactose—UDP-N-acetylglucosamine galactose phosphotransferase
Reaction: UDP-α-D-galactose + UDP-N-acetyl-α-D-glucosamine = UMP + UDP-N-acetyl-6-(α-D-galactose-1-phospho)-α-D-glucosamine
Other name(s): uridine diphosphogalactose-uridine diphosphoacetylglucosamine galactose-1-phosphotransferase; galactose-1-phosphotransferase; galactosyl phosphotransferase; UDP-galactose:UDP-N-acetyl-D-glucosamine galactose phosphotransferase
Systematic name: UDP-α-D-galactose:UDP-N-acetyl-α-D-glucosamine galactose phosphotransferase
Comments: N-Acetylglucosamine end-groups in glycoproteins can also act as acceptors.
References:
1.  Nakanishi, Y., Otsu, K. and Suzuki, S. Enzymatic transfer of galactosyl phosphate from UDP-galactose to UDP-N-acetylglucosamine. FEBS Lett. 151 (1983) 15–18. [PMID: 6130977]
[EC 2.7.8.18 created 1986]
 
 
EC 2.4.1.139     Relevance: 14.9%
Accepted name: maltose synthase
Reaction: 2 α-D-glucose 1-phosphate + H2O = maltose + 2 phosphate
Systematic name: α-D-glucose-1-phosphate:α-D-glucose-1-phosphate 4-α-D-glucosyltransferase (dephosphorylating)
Comments: Neither free phosphate nor maltose 1-phosphate is an intermediate in the reaction.
References:
1.  Schilling, N. Characterization of maltose biosynthesis from α-D-glucose-1-phosphate in Spinacia oleracea L. Planta 154 (1982) 87–93. [PMID: 24275923]
[EC 2.4.1.139 created 1984]
 
 
EC 3.2.1.211     Relevance: 14.9%
Accepted name: endo-(1→3)-fucoidanase
Reaction: endohydrolysis of (1→3)-α-L-fucoside linkages in fucan
Other name(s): α-L-fucosidase (incorrect); poly(1,3-α-L-fucoside-2/4-sulfate) glycanohydrolase
Systematic name: poly[(1→3)-α-L-fucoside-2/4-sulfate] glycanohydrolase
Comments: The enzyme specifically hydrolyses (1→3)-α-L-fucoside linkages in fucan. Fucans are found mainly in different species of seaweed and are sulfated polysaccharides with a backbone of (1→3)-linked or alternating (1→3)- and (1→4)-linked α-L-fucopyranosyl residues. In the literature, the sulfated polysaccharides are often called fucoidans. Fucoidans include polysaccharides with a relatively low proportion of fucose and some polysaccharides that have a backbone composed of other saccharides with fucose in the branching side chains. The sulfation of the α-L-fucopyranosyl residues may occur at positions 2 and 4. The enzyme degrades fucan to sulfated α-L-fucooligosaccharides but neither L-fucose nor small fucooligosaccharides are produced.
References:
1.  Thanassi, N.M. and Nakada, H.I. Enzymic degradation of fucoidan by enzymes from the hepatopancreas of abalone, Halotus species. Arch. Biochem. Biophys. 118 (1967) 172–177.
2.  Bakunina, I.Iu, Nedashkovskaia, O.I., Alekseeva, S.A., Ivanova, E.P., Romanenko, L.A., Gorshkova, N.M., Isakov, V.V., Zviagintseva, T.N. and Mikhailov, V.V. [Degradation of fucoidan by the marine proteobacterium Pseudoalteromonas citrea] Mikrobiologiia 71 (2002) 49–55. [PMID: 11910806] (in Russian)
3.  Berteau, O. and Mulloy, B. Sulfated fucans, fresh perspectives: structures, functions, and biological properties of sulfated fucans and an overview of enzymes active toward this class of polysaccharide. Glycobiology 13 (2003) 29R–40R. [PMID: 12626402]
4.  Bilan, M.I., Kusaykin, M.I., Grachev, A.A., Tsvetkova, E.A., Zvyagintseva, T.N., Nifantiev, N.E. and Usov, A.I. Effect of enzyme preparation from the marine mollusk Littorina kurila on fucoidan from the brown alga Fucus distichus. Biochemistry (Mosc.) 70 (2005) 1321–1326. [PMID: 16417453]
[EC 3.2.1.211 created 1972 as EC 3.2.1.44, part transferred 2020 to EC 3.2.1.211 ]
 
 
EC 3.2.1.212     Relevance: 14.9%
Accepted name: endo-(1→4)-fucoidanase
Reaction: endohydrolysis of (1→4)-α-L-fucoside linkages in fucan
Other name(s): α-L-fucosidase (incorrect); poly(1,4-α-L-fucoside-2/3-sulfate) glycanohydrolase
Systematic name: poly[(1→4)-α-L-fucoside-2/3-sulfate] glycanohydrolase
Comments: The enzyme specifically hydrolyses (1→4)-α-L-fucoside linkages in fucan. Fucans are found mainly in different species of seaweed and are sulfated polysaccharides with a backbone of (1→3)-linked or alternating (1→3)- and (1→4)-linked α-L-fucopyranosyl residues. In the literature, the sulfated polysaccharides are often called fucoidans. Fucoidans include polysaccharides with a relatively low proportion of fucose and some polysaccharides that have a backbone composed of other saccharides with fucose in the branching side chains. The sulfation of the α-L-fucopyranosyl residues may occur at positions 2 and 3. The enzyme degrades fucan to sulfated α-L-fucooligosaccharides but neither L-fucose nor small fucooligosaccharides are produced.
References:
1.  Thanassi, N.M. and Nakada, H.I. Enzymic degradation of fucoidan by enzymes from the hepatopancreas of abalone, Halotus species. Arch. Biochem. Biophys. 118 (1967) 172–177.
2.  Berteau, O. and Mulloy, B. Sulfated fucans, fresh perspectives: structures, functions, and biological properties of sulfated fucans and an overview of enzymes active toward this class of polysaccharide. Glycobiology 13 (2003) 29R–40R. [PMID: 12626402]
3.  Descamps, V., Colin, S., Lahaye, M., Jam, M., Richard, C., Potin, P., Barbeyron, T., Yvin, J.C. and Kloareg, B. Isolation and culture of a marine bacterium degrading the sulfated fucans from marine brown algae. Mar Biotechnol (NY) 8 (2006) 27–39. [PMID: 16222488]
4.  Kim, W.J., Kim, S.M., Lee, Y.H., Kim, H.G., Kim, H.K., Moon, S.H., Suh, H.H., Jang, K.H. and Park, Y.I. Isolation and characterization of marine bacterial strain degrading fucoidan from Korean Undaria pinnatifida Sporophylls. J. Microbiol. Biotechnol. 18 (2008) 616–623. [PMID: 18467852]
5.  Silchenko, A.S., Kusaykin, M.I., Kurilenko, V.V., Zakharenko, A.M., Isakov, V.V., Zaporozhets, T.S., Gazha, A.K. and Zvyagintseva, T.N. Hydrolysis of fucoidan by fucoidanase isolated from the marine bacterium, Formosa algae. Mar. Drugs 11 (2013) 2413–2430. [PMID: 23852092]
6.  Silchenko, A.S., Kusaykin, M.I., Zakharenko, A.M., Menshova, R.V., Khanh, H.H.N., Dmitrenok, P.S., Isakov, V.V., Zvyagintseva, T.N. Endo-1,4-fucoidanase from vietnamese marine mollusk Lambis sp. which producing sulphated fucooligosaccharides. J. Mol. Catal. B 102 (2014) 154–160.
7.  Silchenko, A.S., Ustyuzhanina, N.E., Kusaykin, M.I., Krylov, V.B., Shashkov, A.S., Dmitrenok, A.S., Usoltseva, R.V., Zueva, A.O., Nifantiev, N.E. and Zvyagintseva, T.N. Expression and biochemical characterization and substrate specificity of the fucoidanase from Formosa algae. Glycobiology 27 (2017) 254–263. [PMID: 28031251]
[EC 3.2.1.212 created 1972 as EC 3.2.1.44, part transferred 2020 to EC 3.2.1.212]
 
 
EC 1.1.1.221     Relevance: 14.9%
Accepted name: vomifoliol dehydrogenase
Reaction: (6S,9R)-6-hydroxy-3-oxo-α-ionol + NAD+ = (6S)-6-hydroxy-3-oxo-α-ionone + NADH + H+
Glossary: (6S,9R)-6-hydroxy-3-oxo-α-ionol = vomifoliol = (4S)-4-hydroxy-4-[(1E,3R)-3-hydroxybut-1-en-1-yl]-3,5,5-trimethylcyclohex-2-en-1-one
(6S)-6-hydroxy-3-oxo-α-ionone = dehydrovomifoliol = (4S)-4-hydroxy-3,5,5-trimethyl-4-[(1E)-3-oxobut-1-en-1-yl]cyclohex-2-en-1-one
Other name(s): vomifoliol 4′-dehydrogenase; vomifoliol:NAD+ 4′-oxidoreductase
Systematic name: (6S,9R)-6-hydroxy-3-oxo-α-ionol:NAD+ oxidoreductase
Comments: Oxidizes vomifoliol to dehydrovomifoliol; involved in the metabolism of abscisic acid in Corynebacterium sp.
References:
1.  Hasegawa, S., Poling, S.M., Maier, V.P. and Bennett, R.D. Metabolism of abscisic-acid bacterial conversion to dehydrovomifoliol and vomifoliol dehydrogenase-activity. Phytochemistry 23 (1984) 2769–2771.
[EC 1.1.1.221 created 1989]
 
 
EC 2.7.7.71     Relevance: 14.9%
Accepted name: D-glycero-α-D-manno-heptose 1-phosphate guanylyltransferase
Reaction: D-glycero-α-D-manno-heptose 1-phosphate + GTP = GDP-D-glycero-α-D-manno-heptose + diphosphate
Other name(s): hddC (gene name); gmhD (gene name)
Systematic name: GTP:D-glycero-α-D-manno-heptose 1-phosphate guanylyltransferase
Comments: The enzyme is involved in biosynthesis of GDP-D-glycero-α-D-manno-heptose, which is required for assembly of S-layer glycoprotein in some Gram-positive bacteria.
References:
1.  Kneidinger, B., Graninger, M., Puchberger, M., Kosma, P. and Messner, P. Biosynthesis of nucleotide-activated D-glycero-D-manno-heptose. J. Biol. Chem. 276 (2001) 20935–20944. [PMID: 11279237]
[EC 2.7.7.71 created 2010]
 
 
EC 2.4.1.335     Relevance: 14.8%
Accepted name: dolichyl N-acetyl-α-D-glucosaminyl phosphate 3-β-D-2,3-diacetamido-2,3-dideoxy-β-D-glucuronosyltransferase
Reaction: UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronate + an archaeal dolichyl N-acetyl-α-D-glucosaminyl phosphate = UDP + an archaeal dolichyl 3-O-(2,3-diacetamido-2,3-dideoxy-β-D-glucuronsyl)-N-acetyl-α-D-glucosaminyl phosphate
Other name(s): AglC; UDP-Glc-2,3-diNAcA glycosyltransferase
Systematic name: UDP-2,3-diacetamido-2,3-dideoxy-α-D-glucuronate:dolichyl N-acetyl-α-D-glucosaminyl-phosphate 3-β-D-2,3-diacetamido-2,3-dideoxy-β-D-glucuronosyltransferase
Comments: The enzyme, characterized from the methanogenic archaeon Methanococcus voltae, participates in the N-glycosylation of proteins. Dolichol used by archaea is different from that used by eukaryotes. It is much shorter (C55-C60), it is α,ω-saturated and it may have additional unsaturated positions in the chain.
References:
1.  Larkin, A., Chang, M.M., Whitworth, G.E. and Imperiali, B. Biochemical evidence for an alternate pathway in N-linked glycoprotein biosynthesis. Nat. Chem. Biol. 9 (2013) 367–373. [PMID: 23624439]
[EC 2.4.1.335 created 2015]
 
 
EC 2.4.1.122     Relevance: 14.8%
Accepted name: N-acetylgalactosaminide β-1,3-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-α-D-galactosaminyl-R = UDP + β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-R
Other name(s): glycoprotein-N-acetylgalactosamine 3-β-galactosyltransferase; uridine diphosphogalactose-mucin β-(1→3)-galactosyltransferase; UDP-galactose:glycoprotein-N-acetyl-D-galactosamine 3-β-D-galactosyltransferase; UDP-Gal:α-D-GalNAc-1,3-α-D-GalNAc-diphosphoundecaprenol β-1,3-galactosyltransferase; wbnJ (gene name); wbiP (gene name); C1GALT1 (gene name); UDP-α-D-galactose:glycoprotein-N-acetyl-D-galactosamine 3-β-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-α-D-galactosaminyl-R β-1,3-galactosyltransferase (configuration-inverting)
Comments: The eukaryotic enzyme can act on non-reducing O-serine-linked N-acetylgalactosamine residues in mucin glycoproteins, forming the T-antigen. The bacterial enzyme, found in some pathogenic strains, is involved in biosynthesis of the O-antigen repeating unit.
References:
1.  Hesford, F.J., Berger, E.G. and van den Eijnden, D.H. Identification of the product formed by human erythrocyte galactosyltransferase. Biochim. Biophys. Acta 659 (1981) 302–311. [PMID: 6789880]
2.  Mendicino, J., Sivakami, S., Davila, M. and Chandrasekaran, E.V. Purification and properties of UDP-gal:N-acetylgalactosaminide mucin:β1,3-galactosyltransferase from swine trachea mucosa. J. Biol. Chem. 257 (1982) 3987–3994. [PMID: 6801057]
3.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
4.  Ju, T., Brewer, K., D'Souza, A., Cummings, R.D. and Canfield, W.M. Cloning and expression of human core 1 β1,3-galactosyltransferase. J. Biol. Chem. 277 (2002) 178–186. [PMID: 11677243]
5.  Yi, W., Perali, R.S., Eguchi, H., Motari, E., Woodward, R. and Wang, P.G. Characterization of a bacterial β-1,3-galactosyltransferase with application in the synthesis of tumor-associated T-antigen mimics. Biochemistry 47 (2008) 1241–1248. [PMID: 18179256]
6.  Woodward, R., Yi, W., Li, L., Zhao, G., Eguchi, H., Sridhar, P.R., Guo, H., Song, J.K., Motari, E., Cai, L., Kelleher, P., Liu, X., Han, W., Zhang, W., Ding, Y., Li, M. and Wang, P.G. In vitro bacterial polysaccharide biosynthesis: defining the functions of Wzy and Wzz. Nat. Chem. Biol. 6 (2010) 418–423. [PMID: 20418877]
[EC 2.4.1.122 created 1984 (EC 2.4.1.307 created 2013, incorporated 2016), modified 2016]
 
 
EC 5.4.2.2     Relevance: 14.8%
Accepted name: phosphoglucomutase (α-D-glucose-1,6-bisphosphate-dependent)
Reaction: α-D-glucose 1-phosphate = D-glucose 6-phosphate
Other name(s): glucose phosphomutase (ambiguous); phosphoglucose mutase (ambiguous)
Systematic name: α-D-glucose 1,6-phosphomutase
Comments: Maximum activity is only obtained in the presence of α-D-glucose 1,6-bisphosphate. This bisphosphate is an intermediate in the reaction, being formed by transfer of a phosphate residue from the enzyme to the substrate, but the dissociation of bisphosphate from the enzyme complex is much slower than the overall isomerization. The enzyme also catalyses (more slowly) the interconversion of 1-phosphate and 6-phosphate isomers of many other α-D-hexoses, and the interconversion of α-D-ribose 1-phosphate and 5-phosphate. cf. EC 5.4.2.5, phosphoglucomutase (glucose-cofactor).
References:
1.  Joshi, J.G. and Handler, P. Phosphoglucomutase. I. Purification and properties of phosphoglucomutase from Escherichia coli. J. Biol. Chem. 239 (1964) 2741–2751. [PMID: 14216423]
2.  Najjar, V.A. Phosphoglucomutase. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 6, Academic Press, New York, 1962, pp. 161–178.
3.  Ray, W.J. and Roscelli, G.A. A kinetic study of the phosphoglucomutase pathway. J. Biol. Chem. 239 (1964) 1228–1236. [PMID: 14165931]
4.  Ray, W.J., Jr. and Peck, E.J., Jr. Phosphomutases. In: Boyer, P.D. (Ed.), The Enzymes, 3rd edn, vol. 6, 1972, pp. 407–477.
5.  Sutherland, E.W., Cohn, M., Posternak, T. and Cori, C.F. The mechanism of the phosphoglucomutase reaction. J. Biol. Chem. 180 (1949) 1285–1295. [PMID: 18148026]
[EC 5.4.2.2 created 1961 as EC 2.7.5.1, transferred 1984 to EC 5.4.2.2]
 
 
EC 2.4.1.113     Relevance: 14.8%
Accepted name: α-1,4-glucan-protein synthase (ADP-forming)
Reaction: ADP-glucose + protein = ADP + α-D-glucosyl-protein
Other name(s): ADP-glucose:protein glucosyltransferase; adenosine diphosphoglucose-protein glucosyltransferase
Systematic name: ADP-glucose:protein 4-α-D-glucosyltransferase
Comments: The enzyme builds up α-1,4-glucan chains covalently bound to protein, thus acting as an initiator of glycogen synthesis.
References:
1.  Barengo, R. and Krisman, C.R. Initiation of glycogen biosynthesis in Escherichia coli. Studies of the properties of the enzymes involved. Biochim. Biophys. Acta 540 (1978) 190–196. [PMID: 418819]
[EC 2.4.1.113 created 1984]
 
 
EC 2.4.1.375     Relevance: 14.8%
Accepted name: rhamnogalacturonan I galactosyltransferase
Reaction: Transfer of a β-galactosyl residue in a β-(1→4) linkage from UDP-α-D-galactose to rhamnosyl residues within the rhamnogalacturonan I backbone.
Glossary: rhamnogalacturonan I backbone = [(1→2)-α-L-rhamnosyl-(1→4)-α-D-galacturonosyl]n
Systematic name: UDP-α-D-galactose:[rhamnogalacturonan I]-α-L-rhamnosyl β-1,4-galactosyltransferase (configuration-inverting)
Comments: The enzyme, characterized from the plant Vigna angularis (azuki beans), participates in the biosynthesis of rhamnogalacturonan I, one of the components of pectin in plant cell wall. It does not require any metal ions, and prefers substrates with a degree of polymerization larger than 9.
References:
1.  Matsumoto, N., Takenaka, Y., Wachananawat, B., Kajiura, H., Imai, T. and Ishimizu, T. Rhamnogalacturonan I galactosyltransferase: Detection of enzyme activity and its hyperactivation. Plant Physiol. Biochem. 142 (2019) 173–178. [PMID: 31299599]
[EC 2.4.1.375 created 2020]
 
 
EC 2.4.1.153     Relevance: 14.8%
Accepted name: UDP-N-acetylglucosamine—dolichyl-phosphate N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + dolichyl phosphate = UDP + dolichyl N-acetyl-α-D-glucosaminyl phosphate
Other name(s): aglK (gene name); dolichyl-phosphate α-N-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:dolichyl-phosphate α-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:dolichyl-phosphate α-N-acetyl-D-glucosaminyltransferase
Comments: The enzyme, characterized from the methanogenic archaeon Methanococcus voltae, initiates N-linked glycosylation in that organism. The enzyme differs from the eukaryotic enzyme, which leaves one additional phosphate group on the dolichyl product (cf. EC 2.7.8.15, UDP-N-acetylglucosamine—dolichyl-phosphate N-acetylglucosaminephosphotransferase).
References:
1.  Larkin, A., Chang, M.M., Whitworth, G.E. and Imperiali, B. Biochemical evidence for an alternate pathway in N-linked glycoprotein biosynthesis. Nat. Chem. Biol. 9 (2013) 367–373. [PMID: 23624439]
[EC 2.4.1.153 created 1984, modified 2015]
 
 
EC 2.3.1.241     Relevance: 14.8%
Accepted name: Kdo2-lipid IVA acyltransferase
Reaction: a fatty acyl-[acyl-carrier protein] + an α-Kdo-(2→4)-α-Kdo-(2→6)-[lipid IVA] = an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] + an [acyl-carrier protein]
Glossary: Kdo = 3-deoxy-D-manno-oct-2-ulopyranosylonic acid
a lipid IVA = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose
an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] = 3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→4)-3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→6)-2-deoxy-2-{[(3R)-3-(acyloxy)acyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phosphono-α-D-glucopyranose
Other name(s): LpxL; htrB (gene name); dodecanoyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA O-dodecanoyltransferase; lauroyl-[acyl-carrier protein]:Kdo2-lipid IVA O-lauroyltransferase; (Kdo)2-lipid IVA lauroyltransferase; α-Kdo-(2→4)-α-(2→6)-lipid IVA lauroyltransferase; dodecanoyl-[acyl-carrier protein]:Kdo2-lipid IVA O-dodecanoyltransferase; Kdo2-lipid IVA lauroyltransferase
Systematic name: fatty acyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-[lipid IVA] O-acyltransferase
Comments: The enzyme is involved in the biosynthesis of the phosphorylated outer membrane glycolipid lipid A. It transfers an acyl group to the 3-O position of the 3R-hydroxyacyl already attached to the nitrogen of the non-reducing glucosamine molecule. The enzyme from the bacterium Escherichia coli is specific for lauryl (C12) acyl groups, giving the enzyme its previous accepted name. However, enzymes from different species accept highly variable substrates.
References:
1.  Clementz, T., Bednarski, J.J. and Raetz, C.R. Function of the htrB high temperature requirement gene of Escherichia coli in the acylation of lipid A: HtrB catalyzed incorporation of laurate. J. Biol. Chem. 271 (1996) 12095–12102. [PMID: 8662613]
2.  van der Ley, P., Steeghs, L., Hamstra, H.J., ten Hove, J., Zomer, B. and van Alphen, L. Modification of lipid A biosynthesis in Neisseria meningitidis lpxL mutants: influence on lipopolysaccharide structure, toxicity, and adjuvant activity. Infect. Immun. 69 (2001) 5981–5990. [PMID: 11553534]
3.  McLendon, M.K., Schilling, B., Hunt, J.R., Apicella, M.A. and Gibson, B.W. Identification of LpxL, a late acyltransferase of Francisella tularensis. Infect. Immun. 75 (2007) 5518–5531. [PMID: 17724076]
4.  Six, D.A., Carty, S.M., Guan, Z. and Raetz, C.R. Purification and mutagenesis of LpxL, the lauroyltransferase of Escherichia coli lipid A biosynthesis. Biochemistry 47 (2008) 8623–8637. [PMID: 18656959]
5.  Fathy Mohamed, Y., Hamad, M., Ortega, X.P. and Valvano, M.A. The LpxL acyltransferase is required for normal growth and penta-acylation of lipid A in Burkholderia cenocepacia. Mol. Microbiol. 104 (2017) 144–162. [PMID: 28085228]
[EC 2.3.1.241 created 2014, modified 2021]
 
 
EC 2.4.1.180     Relevance: 14.8%
Accepted name: lipopolysaccharide N-acetylmannosaminouronosyltransferase
Reaction: UDP-N-acetyl-α-D-mannosaminouronate + N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = UDP + N-acetyl-β-D-mannosaminouronyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol
Glossary: N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = lipid I = GlcNAc-pyrophosphorylundecaprenol = ditrans,octacis-undecaprenyl-N-acetyl-α-D-glucosaminyl diphosphate
Other name(s): ManNAcA transferase; uridine diphosphoacetylmannosaminuronate-acetylglucosaminylpyrophosphorylundecaprenol acetylmannosaminuronosyltransferase; UDP-N-acetyl-β-D-mannosaminouronate:lipid I N-acetyl-β-D-mannosaminouronosyltransferase (incorrect)
Systematic name: UDP-N-acetyl-α-D-mannosaminouronate:lipid I N-acetyl-α-D-mannosaminouronosyltransferase
Comments: Involved in the biosynthesis of common antigen in Enterobacteriaceae.
References:
1.  Barr, K., Ward, S., Meier-Dieter, U., Mayer, H. and Rick, P.D. Characterization of an Escherichia coli rff mutant defective in transfer of N-acetylmannosaminuronic acid (ManNAcA) from UDP-ManNAcA to a lipid-linked intermediate involved in enterobacterial common antigen synthesis. J. Bacteriol. 170 (1988) 228–233. [PMID: 3275612]
[EC 2.4.1.180 created 1990, modified 2011]
 
 
EC 3.2.1.171     Relevance: 14.8%
Accepted name: rhamnogalacturonan hydrolase
Reaction: Endohydrolysis of α-D-GalA-(1→2)-α-L-Rha glycosidic bond in the rhamnogalacturonan I backbone with initial inversion of anomeric configuration releasing oligosaccharides with β-D-GalA at the reducing end.
Other name(s): rhamnogalacturonase A; RGase A; RG-hydrolase
Systematic name: rhamnogalacturonan α-D-GalA-(1→2)-α-L-Rha hydrolase
Comments: The enzyme is part of the degradation system for rhamnogalacturonan I in Aspergillus aculeatus.
References:
1.  Petersen, T.N., Kauppinen, S. and Larsen, S. The crystal structure of rhamnogalacturonase A from Aspergillus aculeatus: a right-handed parallel β helix. Structure 5 (1997) 533–544. [PMID: 9115442]
2.  Kofod, L.V., Kauppinen, S., Christgau, S., Andersen, L.N., Heldt-Hansen, H.P., Dorreich, K. and Dalboge, H. Cloning and characterization of two structurally and functionally divergent rhamnogalacturonases from Aspergillus aculeatus. J. Biol. Chem. 269 (1994) 29182–29189. [PMID: 7961884]
3.  Azadi, P., O'Neill, M.A., Bergmann, C., Darvill, A.G. and Albersheim, P. The backbone of the pectic polysaccharide rhamnogalacturonan I is cleaved by an endohydrolase and an endolyase. Glycobiology 5 (1995) 783–789. [PMID: 8720076]
4.  Petersen, T.N., Christgau, S., Kofod, L.V., Kauppinen, S., Johnson, A.H. and Larsen, S. Crystallization and preliminary X-ray studies of rhamnogalacturonase A from Aspergillus aculeatus. Acta Crystallogr. D Biol. Crystallogr. 53 (1997) 105–107. [PMID: 15299976]
5.  Pitson, S.M., Mutter, M., van den Broek, L.A., Voragen, A.G. and Beldman, G. Stereochemical course of hydrolysis catalysed by α-L-rhamnosyl and α-D-galacturonosyl hydrolases from Aspergillus aculeatus. Biochem. Biophys. Res. Commun. 242 (1998) 552–559. [PMID: 9464254]
[EC 3.2.1.171 created 2011]
 
 
EC 4.4.1.32     Relevance: 14.8%
Accepted name: C-phycocyanin α-cysteine-84 phycocyanobilin lyase
Reaction: [C-phycocyanin α-subunit]-Cys84-phycocyanobilin = apo-[C-phycocyanin α-subunit] + (2R,3E)-phycocyanobilin
Glossary: phycocyanobilin = 3,31-didehydro-2,3-dihydromesobiliverdin
Other name(s): cpcE (gene name); cpcF (gene name)
Systematic name: [C-phycocyanin α-subunit]-Cys84-phycocyanobilin:(2R,3E)-phycocyanobilin lyase
Comments: The enzyme, characterized from the cyanobacterium Synechococcus elongatus PCC 7942, catalyses the covalent attachment of the phycobilin chromophore phycocyanobilin to cysteine 84 of the α subunit of the phycobiliprotein C-phycocyanin.
References:
1.  Fairchild, C.D., Zhao, J., Zhou, J., Colson, S.E., Bryant, D.A. and Glazer, A.N. Phycocyanin α-subunit phycocyanobilin lyase. Proc. Natl. Acad. Sci. USA 89 (1992) 7017–7021. [PMID: 1495995]
2.  Fairchild, C.D. and Glazer, A.N. Oligomeric structure, enzyme kinetics, and substrate specificity of the phycocyanin α subunit phycocyanobilin lyase. J. Biol. Chem. 269 (1994) 8686–8694. [PMID: 8132596]
3.  Bhalerao, R.P., Lind, L.K. and Gustafsson, P. Cloning of the cpcE and cpcF genes from Synechococcus sp. PCC 6301 and their inactivation in Synechococcus sp. PCC 7942. Plant Mol. Biol. 26 (1994) 313–326. [PMID: 7524727]
[EC 4.4.1.32 created 2015]
 
 
EC 2.4.1.304     Relevance: 14.8%
Accepted name: UDP-Gal:α-D-GlcNAc-diphosphoundecaprenol β-1,4-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol = UDP + β-D-Gal-(1→4)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WfeD; UDP-Gal:GlcNAc-R 1,4-Gal-transferase; UDP-Gal:GlcNAc-pyrophosphate-lipid β-1,4-galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-α-D-glucosaminyl-diphospho-ditrans,octacis-undecaprenol β-1,4-galactosyltransferase
Comments: The enzyme is involved in the the biosynthesis of the O-polysaccharide repeating unit of the bacterium Shigella boydii B14. The activity is stimulated by Mn2+ or to a lesser extent by Mg2+, Ca2+, Ni2+ or Pb2+.
References:
1.  Xu, C., Liu, B., Hu, B., Han, Y., Feng, L., Allingham, J.S., Szarek, W.A., Wang, L. and Brockhausen, I. Biochemical characterization of UDP-Gal:GlcNAc-pyrophosphate-lipid β-1,4-Galactosyltransferase WfeD, a new enzyme from Shigella boydii type 14 that catalyzes the second step in O-antigen repeating-unit synthesis. J. Bacteriol. 193 (2011) 449–459. [PMID: 21057010]
[EC 2.4.1.304 created 2013]
 
 
EC 2.3.1.283     Relevance: 14.7%
Accepted name: 2′-acyl-2-O-sulfo-trehalose (hydroxy)phthioceranyltransferase
Reaction: a (hydroxy)phthioceranyl-[(hydroxy)phthioceranic acid synthase] + 2′-palmitoyl/stearoyl-2-O-sulfo-α,α-trehalose = a 3′-(hydroxy)phthioceranyl-2′-palmitoyl/stearoyl-2-O-sulfo-α,α-trehalose + holo-[(hydroxy)phthioceranic acid synthase]
Other name(s): papA1 (gene name)
Systematic name: (hydroxy)phthioceranyl-[(hydroxy)phthioceranic acid synthase]:2′-acyl-2-O-sulfo-α,α-trehalose 3′-(hydroxy)phthioceranyltransferase
Comments: This mycobacterial enzyme catalyses the acylation of 2′-palmitoyl/stearoyl-2-O-sulfo-α,α-trehalose at the 3′ position by a (hydroxy)phthioceranoyl group during the biosynthesis of mycobacterial sulfolipids.
References:
1.  Bhatt, K., Gurcha, S.S., Bhatt, A., Besra, G.S. and Jacobs, W.R., Jr. Two polyketide-synthase-associated acyltransferases are required for sulfolipid biosynthesis in Mycobacterium tuberculosis. Microbiology 153 (2007) 513–520. [PMID: 17259623]
2.  Kumar, P., Schelle, M.W., Jain, M., Lin, F.L., Petzold, C.J., Leavell, M.D., Leary, J.A., Cox, J.S. and Bertozzi, C.R. PapA1 and PapA2 are acyltransferases essential for the biosynthesis of the Mycobacterium tuberculosis virulence factor sulfolipid-1. Proc. Natl. Acad. Sci. USA 104 (2007) 11221–11226. [PMID: 17592143]
[EC 2.3.1.283 created 2019]
 
 
EC 4.2.1.76     Relevance: 14.7%
Accepted name: UDP-glucose 4,6-dehydratase
Reaction: UDP-α-D-glucose = UDP-4-dehydro-6-deoxy-α-D-glucose + H2O
Other name(s): UDP-D-glucose-4,6-hydrolyase; UDP-D-glucose oxidoreductase; UDP-glucose 4,6-hydro-lyase
Systematic name: UDP-α-D-glucose 4,6-hydro-lyase (UDP-4-dehydro-6-deoxy-α-D-glucose-forming)
References:
1.  Kamsteeg, J., van Brederode, J. and van Nigtevecht, G. The formation of UDP-L-rhamnose from UDP-D-glucose by an enzyme preparation of red campion (Silene dioica (L) Clairv) leaves. FEBS Lett. 91 (1978) 281–284. [PMID: 680134]
[EC 4.2.1.76 created 1984]
 
 
EC 3.2.1.173     Relevance: 14.7%
Accepted name: rhamnogalacturonan galacturonohydrolase
Reaction: Exohydrolysis of the α-D-GalA-(1→2)-α-L-Rha bond in rhamnogalacturonan oligosaccharides with initial inversion of configuration releasing D-galacturonic acid from the non-reducing end of rhamnogalacturonan oligosaccharides.
Other name(s): RG-galacturonohydrolase
Systematic name: rhamnogalacturonan oligosaccharide α-D-GalA-(1→2)-α-L-Rha galacturonohydrolase
Comments: The enzyme is part of the degradation system for rhamnogalacturonan I in Aspergillus aculeatus.
References:
1.  Mutter, M., Beldman, G., Pitson, S.M., Schols, H.A. and Voragen, A.G. Rhamnogalacturonan α-D-galactopyranosyluronohydrolase. An enzyme that specifically removes the terminal nonreducing galacturonosyl residue in rhamnogalacturonan regions of pectin. Plant Physiol. 117 (1998) 153–163. [PMID: 9576784]
[EC 3.2.1.173 created 2011]
 
 
EC 2.7.1.166     Relevance: 14.7%
Accepted name: 3-deoxy-D-manno-octulosonic acid kinase
Reaction: α-Kdo-(2→6)-lipid IVA + ATP = 4-O-phospho-α-Kdo-(2→6)-lipid IVA + ADP
Glossary: (Kdo)-lipid IVA = α-Kdo-(2→6)-lipid IVA = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
(4-O-phospho-KDO)-lipid IVA = 4-O-phospho-α-Kdo-(2→6)-lipid IVA = (3-deoxy-4-O-phosphono-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
Other name(s): kdkA (gene name); Kdo kinase
Systematic name: ATP:(Kdo)-lipid IVA 3-deoxy-α-D-manno-oct-2-ulopyranose 4-phosphotransferase
Comments: The enzyme phosphorylates the 4-OH position of Kdo in (Kdo)-lipid IVA.
References:
1.  Brabetz, W., Muller-Loennies, S. and Brade, H. 3-Deoxy-D-manno-oct-2-ulosonic acid (Kdo) transferase (WaaA) and kdo kinase (KdkA) of Haemophilus influenzae are both required to complement a waaA knockout mutation of Escherichia coli. J. Biol. Chem. 275 (2000) 34954–34962. [PMID: 10952982]
2.  Harper, M., Boyce, J.D., Cox, A.D., St Michael, F., Wilkie, I.W., Blackall, P.J. and Adler, B. Pasteurella multocida expresses two lipopolysaccharide glycoforms simultaneously, but only a single form is required for virulence: identification of two acceptor-specific heptosyl I transferases. Infect. Immun. 75 (2007) 3885–3893. [PMID: 17517879]
3.  White, K.A., Kaltashov, I.A., Cotter, R.J. and Raetz, C.R. A mono-functional 3-deoxy-D-manno-octulosonic acid (Kdo) transferase and a Kdo kinase in extracts of Haemophilus influenzae. J. Biol. Chem. 272 (1997) 16555–16563. [PMID: 9195966]
4.  White, K.A., Lin, S., Cotter, R.J. and Raetz, C.R. A Haemophilus influenzae gene that encodes a membrane bound 3-deoxy-D-manno-octulosonic acid (Kdo) kinase. Possible involvement of kdo phosphorylation in bacterial virulence. J. Biol. Chem. 274 (1999) 31391–31400. [PMID: 10531340]
[EC 2.7.1.166 created 2010, modified 2011]
 
 
EC 2.4.2.43     Relevance: 14.7%
Accepted name: lipid IVA 4-amino-4-deoxy-L-arabinosyltransferase
Reaction: (1) 4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl phosphate + α-Kdo-(2→4)-α-Kdo-(2→6)-lipid A = α-Kdo-(2→4)-α-Kdo-(2→6)-[4-P-L-Ara4N]-lipid A + ditrans,octacis-undecaprenyl phosphate
(2) 4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl phosphate + lipid IVA = lipid IIA + ditrans,octacis-undecaprenyl phosphate
(3) 4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl phosphate + α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA = 4′-α-L-Ara4N-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA + ditrans,octacis-undecaprenyl phosphate
Glossary: lipid IVA = 2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
lipid IIA = 4-amino-4-deoxy-β-L-arabinopyranosyl 2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-α-D-glucopyranosyl phosphate
α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-hydroxytetradecanoyl]amino}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phosphono-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
4′-α-L-Ara4N-α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA = 4-amino-4-deoxy-α-L-arabinopyranosyl 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-phospho-β-D-glucopyranosy-(1→6)-2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-α-D-glucopyranosyl phosphate
lipid A = lipid A of Escherichia coli = 2-deoxy-2-{[(3R)-3-(dodecanoyloxy)tetradecanoyl]amino}-3-O-[(3R)-3-(tetradecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
α-Kdo-(2→4)-α-Kdo-(2→6)-lipid A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-(dodecanoyloxy)tetradecanoyl]amino}-3-O-[(3R)-3-(tetradecanoyloxy)tetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
α-Kdo-(2→4)-α-Kdo-(2→6)-[4′-P-α-L-Ara4N]-lipid A = (3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→4)-(3-deoxy-α-D-manno-oct-2-ulopyranosylonate)-(2→6)-2-deoxy-2-{[(3R)-3-(dodecanoyloxy)tetradecanoyl]amino}-3-O-[(3R)-3-(tetradecanoyloxy)tetradecanoyl]-4-O-(4-amino-4-deoxy-α-L-arabinopyranosyl)phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-{[(3R)-3-hydroxytetradecanoyl]amino}-1-O-phosphono-α-D-glucopyranose
Other name(s): undecaprenyl phosphate-α-L-Ara4N transferase; 4-amino-4-deoxy-L-arabinose lipid A transferase; polymyxin resistance protein PmrK; arnT (gene name)
Systematic name: 4-amino-4-deoxy-α-L-arabinopyranosyl ditrans,octacis-undecaprenyl-phosphate:lipid IVA 4-amino-4-deoxy-L-arabinopyranosyltransferase
Comments: Integral membrane protein present in the inner membrane of certain Gram negative endobacteria. In strains that do not produce 3-deoxy-D-manno-octulosonic acid (Kdo), the enzyme adds a single arabinose unit to the 1-phosphate moiety of the tetra-acylated lipid A precursor, lipid IVA. In the presence of a Kdo disaccharide, the enzyme primarily adds an arabinose unit to the 4-phosphate of lipid A molecules. The Salmonella typhimurium enzyme can add arabinose units to both positions.
References:
1.  Trent, M.S., Ribeiro, A.A., Lin, S., Cotter, R.J. and Raetz, C.R. An inner membrane enzyme in Salmonella and Escherichia coli that transfers 4-amino-4-deoxy-L-arabinose to lipid A: induction on polymyxin-resistant mutants and role of a novel lipid-linked donor. J. Biol. Chem. 276 (2001) 43122–43131. [PMID: 11535604]
2.  Trent, M.S., Ribeiro, A.A., Doerrler, W.T., Lin, S., Cotter, R.J. and Raetz, C.R. Accumulation of a polyisoprene-linked amino sugar in polymyxin-resistant Salmonella typhimurium and Escherichia coli: structural characterization and transfer to lipid A in the periplasm. J. Biol. Chem. 276 (2001) 43132–43144. [PMID: 11535605]
3.  Zhou, Z., Ribeiro, A.A., Lin, S., Cotter, R.J., Miller, S.I. and Raetz, C.R. Lipid A modifications in polymyxin-resistant Salmonella typhimurium: PMRA-dependent 4-amino-4-deoxy-L-arabinose, and phosphoethanolamine incorporation. J. Biol. Chem. 276 (2001) 43111–43121. [PMID: 11535603]
4.  Bretscher, L.E., Morrell, M.T., Funk, A.L. and Klug, C.S. Purification and characterization of the L-Ara4N transferase protein ArnT from Salmonella typhimurium. Protein Expr. Purif. 46 (2006) 33–39. [PMID: 16226890]
5.  Impellitteri, N.A., Merten, J.A., Bretscher, L.E. and Klug, C.S. Identification of a functionally important loop in Salmonella typhimurium ArnT. Biochemistry 49 (2010) 29–35. [PMID: 19947657]
[EC 2.4.2.43 created 2010, modified 2011]
 
 
EC 2.4.1.40     Relevance: 14.7%
Accepted name: glycoprotein-fucosylgalactoside α-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + glycoprotein-α-L-fucosyl-(1→2)-D-galactose = UDP + glycoprotein-N-acetyl-α-D-galactosaminyl-(1→3)-[α-L-fucosyl-(1→2)]-D-galactose
Other name(s): A-transferase; histo-blood group A glycosyltransferase (Fucα1→2Galα1→3-N-acetylgalactosaminyltransferase); UDP-GalNAc:Fucα1→2Galα1→3-N-acetylgalactosaminyltransferase; α-3-N-acetylgalactosaminyltransferase; blood-group substance α-acetyltransferase; blood-group substance A-dependent acetylgalactosaminyltransferase; fucosylgalactose acetylgalactosaminyltransferase; histo-blood group A acetylgalactosaminyltransferase; histo-blood group A transferase; UDP-N-acetyl-D-galactosamine:α-L-fucosyl-1,2-D-galactose 3-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:glycoprotein-α-L-fucosyl-(1,2)-D-galactose 3-N-acetyl-D-galactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:glycoprotein-α-L-fucosyl-(1→2)-D-galactose 3-N-acetyl-D-galactosaminyltransferase
Comments: Acts on blood group substance, and can use a number of 2-fucosyl-galactosides as acceptors.
References:
1.  Kobata, A., Grollman, E.F. and Ginsburg, V. An enzymic basis for blood type A in humans. Arch. Biochem. Biophys. 124 (1968) 609–612. [PMID: 5661629]
2.  Takeya, A., Hosomi, O. and Ishiura, M. Complete purification and characterization of α-3-N-acetylgalactosaminyltransferase encoded by the human blood group A gene. J. Biochem. (Tokyo) 107 (1990) 360–368. [PMID: 2341371]
3.  Yates, A.D., Feeney, J., Donald, A.S.R. and Watkins, W.M. Characterization of a blood-group A-active tetrasaccharide synthesized by a blood-group-B gene-specified glycosyltransferase. Carbohydr. Res. 130 (1984) 251–260. [PMID: 6434182]
[EC 2.4.1.40 created 1972, modified 1999]
 
 
EC 2.3.1.243     Relevance: 14.7%
Accepted name: acyl-Kdo2-lipid IVA acyltransferase
Reaction: a fatty acyl-[acyl-carrier protein] + an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] = an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)2-[lipid IVA] + an [acyl-carrier protein]
Glossary: Kdo = 3-deoxy-D-manno-oct-2-ulopyranosylonic acid
a lipid IVA = 2-deoxy-2-{[(3R)-3-hydroxyacyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose
an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] = 3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→4)-3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→6)-2-deoxy-2-{[(3R)-3-(acyloxy)acyl]amino}-3-O-[(3R)-3-hydroxyacyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phosphono-α-D-glucopyranose
an α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)2-[lipid IVA] = 3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→4)-3-deoxy-α-D-manno-oct-2-ulopyranosyl-(2→6)-2-deoxy-2-{[(3R)-3-(acyloxy)acyl]amino}-3-O-[(3R)-3-(acyloxy)acyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxyacyl]-2-{[(3R)-3-hydroxyacyl]amino}-1-O-phospho-α-D-glucopyranose
Other name(s): lpxM (gene name); MsbB acyltransferase; myristoyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-(dodecanoyl)-lipid IVA O-myristoyltransferase; tetradecanoyl-[acyl-carrier protein]:dodecanoyl-Kdo2-lipid IVA O-tetradecanoyltransferase; lauroyl-Kdo2-lipid IVA myristoyltransferase
Systematic name: fatty acyl-[acyl-carrier protein]:α-Kdo-(2→4)-α-Kdo-(2→6)-(acyl)-[lipid IVA] O-acyltransferase
Comments: The enzyme is involved in the biosynthesis of the phosphorylated outer membrane glycolipid lipid A. It transfers an acyl group to the 3-O position of the 3R-hydroxyacyl already attached at the 2-O position of the non-reducing glucosamine molecule. The enzyme from the bacterium Escherichia coli is specific for myristoyl (C14) acyl groups, giving the enzyme its previous accepted name. However, enzymes from different species accept highly variable substrates.
References:
1.  Clementz, T., Zhou, Z. and Raetz, C.R. Function of the Escherichia coli msbB gene, a multicopy suppressor of htrB knockouts, in the acylation of lipid A. Acylation by MsbB follows laurate incorporation by HtrB. J. Biol. Chem. 272 (1997) 10353–10360. [PMID: 9099672]
2.  Dovala, D., Rath, C.M., Hu, Q., Sawyer, W.S., Shia, S., Elling, R.A., Knapp, M.S. and Metzger, L.E., 4th. Structure-guided enzymology of the lipid A acyltransferase LpxM reveals a dual activity mechanism. Proc. Natl. Acad. Sci. USA 113 (2016) E6064–E6071. [PMID: 27681620]
[EC 2.3.1.243 created 2014, modified 2021]
 
 
EC 2.4.1.213     Relevance: 14.6%
Accepted name: glucosylglycerol-phosphate synthase
Reaction: ADP-α-D-glucose + sn-glycerol 3-phosphate = 2-(α-D-glucopyranosyl)-sn-glycerol 3-phosphate + ADP
Other name(s): ADP-glucose:sn-glycerol-3-phosphate 2-β-D-glucosyltransferase (incorrect)
Systematic name: ADP-α-D-glucose:sn-glycerol-3-phosphate 2-α-D-glucopyranosyltransferase
Comments: Acts with EC 3.1.3.69 (glucosylglycerol phosphatase) to form glucosylglycerol, an osmolyte that endows cyanobacteria with resistance to salt.
References:
1.  Hagemann, M. and Erdmann, N. Activation and pathway of glucosylglycerol biosynthesis in the cyanobacterium Synechocystis sp. PCC 6803. Microbiology 140 (1994) 1427–1431.
2.  Marin, K., Zuther, E., Kerstan, T., Kunert, A. and Hagemann, M. The ggpS gene from Synechocystis sp. strain PCC 6803 encoding glucosylglycerol-phosphate synthase is involved in osmolyte synthesis. J. Bacteriol. 180 (1998) 4843–4849. [PMID: 9733686]
[EC 2.4.1.213 created 2001, modified 2015]
 
 
EC 5.4.2.8     Relevance: 14.6%
Accepted name: phosphomannomutase
Reaction: α-D-mannose 1-phosphate = D-mannose 6-phosphate
Other name(s): mannose phosphomutase; phosphomannose mutase; D-mannose 1,6-phosphomutase
Systematic name: α-D-mannose 1,6-phosphomutase
Comments: α-D-Mannose 1,6-bisphosphate or α-D-glucose 1,6-bisphosphate can act as cofactor.
References:
1.  Small, D.M. and Matheson, N.K. Phosphomannomutase and phosphoglucomutase in developing Cassia corymbosa seeds. Phytochemistry 18 (1979) 1147–1150.
[EC 5.4.2.8 created 1981 as EC 2.7.5.7, transferred 1984 to EC 5.4.2.8]
 
 
EC 2.4.2.2     Relevance: 14.6%
Accepted name: pyrimidine-nucleoside phosphorylase
Reaction: (1) uridine + phosphate = uracil + α-D-ribose 1-phosphate
(2) cytidine + phosphate = cytosine + α-D-ribose 1-phosphate
(3) 2′-deoxyuridine + phosphate = uracil + 2-deoxy-α-D-ribose 1-phosphate
(4) thymidine + phosphate = thymine + 2-deoxy-α-D-ribose 1-phosphate
Other name(s): Py-NPase; pdp (gene name)
Systematic name: pyrimidine-nucleoside:phosphate (2′-deoxy)-α-D-ribosyltransferase
Comments: Unlike EC 2.4.2.3, uridine phosphorylase, and EC 2.4.2.4, thymidine phosphorylase, this enzyme can accept both the ribonucleosides uridine and cytidine and the 2′-deoxyribonucleosides 2′-deoxyuridine and thymidine [3,6]. The reaction is reversible, and the enzyme does not distinguish between α-D-ribose 1-phosphate and 2-deoxy-α-D-ribose 1-phosphate in the synthetic direction.
References:
1.  Friedkin, M. and Kalckar, H. Nucleoside phosphorylases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 5, Academic Press, New York, 1961, pp. 237–255.
2.  Saunders, P.P., Wilson, B.A. and Saunders, G.F. Purification and comparative properties of a pyrimidine nucleoside phosphorylase from Bacillus stearothermophilus. J. Biol. Chem. 244 (1969) 3691–3697. [PMID: 4978445]
3.  Hamamoto, T., Noguchi, T. and Midorikawa, Y. Purification and characterization of purine nucleoside phosphorylase and pyrimidine nucleoside phosphorylase from Bacillus stearothermophilus TH 6-2. Biosci. Biotechnol. Biochem. 60 (1996) 1179–1180. [PMID: 8782414]
4.  Okuyama, K., Hamamoto, T., Noguchi, T. and Midorikawa, Y. Molecular cloning and expression of the pyrimidine nucleoside phosphorylase gene from Bacillus stearothermophilus TH 6-2. Biosci. Biotechnol. Biochem. 60 (1996) 1655–1659. [PMID: 8987664]
5.  Pugmire, M.J. and Ealick, S.E. The crystal structure of pyrimidine nucleoside phosphorylase in a closed conformation. Structure 6 (1998) 1467–1479. [PMID: 9817849]
6.  Wei, X.K., Ding, Q.B., Zhang, L., Guo, Y.L., Ou, L. and Wang, C.L. Induction of nucleoside phosphorylase in Enterobacter aerogenes and enzymatic synthesis of adenine arabinoside. J Zhejiang Univ Sci B 9 (2008) 520–526. [PMID: 18600781]
[EC 2.4.2.2 created 1961, modified 2021]
 
 
EC 2.1.1.307     Relevance: 14.6%
Accepted name: 8-demethyl-8-(2,3-dimethoxy-α-L-rhamnosyl)tetracenomycin-C 4′-O-methyltransferase
Reaction: S-adenosyl-L-methionine + 8-demethyl-8-(2,3-di-O-methyl-α-L-rhamnosyl)tetracenomycin C = S-adenosyl-L-homocysteine + 8-demethyl-8-(2,3,4-tri-O-methyl-α-L-rhamnosyl)tetracenomycin C
Glossary: 8-demethyl-8-α-L-rhamnosyltetracenomycin C = methyl (6aR,7S,10aR)-6a,7,10a,12-tetrahydroxy-8-methoxy-1-methyl-6,10,11-trioxo-3-α-L-rhamnosyloxy-6,6a,7,10,10a,11-hexahydrotetracene-2-carboxylate
Other name(s): ElmMIII
Systematic name: S-adenosyl-L-methionine:8-demethyl-8-(2,3-di-O-methoxy-α-L-rhamnosyl)tetracenomycin-C 4′-O-methyltransferase
Comments: The enzyme from the bacterium Streptomyces olivaceus is involved in the biosynthesis of the polyketide elloramycin.
References:
1.  Patallo, E.P., Blanco, G., Fischer, C., Brana, A.F., Rohr, J., Mendez, C. and Salas, J.A. Deoxysugar methylation during biosynthesis of the antitumor polyketide elloramycin by Streptomyces olivaceus. Characterization of three methyltransferase genes. J. Biol. Chem. 276 (2001) 18765–18774. [PMID: 11376004]
[EC 2.1.1.307 created 2014]
 
 
EC 4.2.3.184     Relevance: 14.6%
Accepted name: 5-hydroxy-α-gurjunene synthase
Reaction: (2E,6E)-farnesyl diphosphate + H2O = 5-hydroxy-α-gurjunene + diphosphate
Other name(s): MpMTPSL4
Systematic name: (2E,6E)-farnesyl-diphosphate diphosphate-lyase (cyclizing, 5-hydroxy-α-gurjunene-forming)
Comments: Isolated from the liverwort Marchantia polymorpha.
References:
1.  Kumar, S., Kempinski, C., Zhuang, X., Norris, A., Mafu, S., Zi, J., Bell, S.A., Nybo, S.E., Kinison, S.E., Jiang, Z., Goklany, S., Linscott, K.B., Chen, X., Jia, Q., Brown, S.D., Bowman, J.L., Babbitt, P.C., Peters, R.J., Chen, F. and Chappell, J. Molecular diversity of terpene synthases in the liverwort Marchantia polymorpha. Plant Cell 28 (2016) 2632–2650. [PMID: 27650333]
[EC 4.2.3.184 created 2017]
 
 
EC 2.4.1.224     Relevance: 14.6%
Accepted name: glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-α-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-D-glucosamine + β-D-glucuronosyl-(1→4)-N-acetyl-α-D-glucosaminyl-proteoglycan = UDP + N-acetyl-α-D-glucosaminyl-(1→4)-β-D-glucuronosyl-(1→4)-N-acetyl-α-D-glucosaminyl-proteoglycan
Other name(s): α-N-acetylglucosaminyltransferase II glucuronyl-N-acetylglucosaminylproteoglycan α-1,4-N-acetylglucosaminyltransferase
Systematic name: UDP-N-acetyl-D-glucosamine:β-D-glucuronosyl-(1→4)-N-acetyl-α-D-glucosaminyl-proteoglycan 4-α-N-acetylglucosaminyltransferase
Comments: Involved in the biosynthesis of heparin and heparan sulfate. Some forms of the enzyme from human (particularly the enzyme complex encoded by the EXT1 and EXT2 genes) act as bifunctional glycosyltransferases, which also have the 4-β-glucuronosyltransferase (EC 2.4.1.225, N-acetylglucosaminyl-proteoglycan 4-β-glucuronosyltransferase) activity required for the synthesis of the heparan sulfate disaccharide repeats. Other human forms of this enzyme (e.g. the product of the EXTL1 gene) have only the 4-α-N-acetylglucosaminyltransferase activity. In Caenorhabditis elegans, the product of the rib-2 gene displays the activities of this enzyme as well as EC 2.4.1.223, glucuronosyl-galactosyl-proteoglycan 4-α-N-acetylglucosaminyltransferase.
References:
1.  Kim, B.T., Kitagawa, H., Tamura, J., Saito, T., Kusche-Gullberg, M., Lindahl, U. and Sugahara, K. Human tumor suppressor EXT gene family members EXTL1 and EXTL3 encode α1,4-N-acetylglucosaminyltransferases that likely are involved in heparan sulfate/heparin biosynthesis. Proc. Natl. Acad. Sci. USA 98 (2001) 7176–7181. [PMID: 11390981]
2.  Kitagawa, H., Egusa, N., Tamura, J.I., Kusche-Gullberg, M., Lindahl, U. and Sugahara, K. rib-2, a Caenorhabditis elegans homolog of the human tumor suppressor EXT genes encodes a novel α1,4-N-acetylglucosaminyltransferase involved in the biosynthetic initiation and elongation of heparan sulfate. J. Biol. Chem. 276 (2001) 4834–4838. [PMID: 11121397]
3.  Senay, C., Lind, T., Muguruma, K., Tone, Y., Kitagawa, H., Sugahara, K., Lidholt, K., Lindahl, U. and Kusche-Gullberg, M. The EXT1/EXT2 tumor suppressors: catalytic activities and role in heparan sulfate biosynthesis. EMBO Rep. 1 (2000) 282–286. [PMID: 11256613]
4.  Lind, T., Tufaro, F., McCormick, C., Lindahl, U. and Lidholt, K. The putative tumor suppressors EXT1 and EXT2 are glycosyltransferases required for the biosynthesis of heparan sulfate. J. Biol. Chem. 273 (1998) 26265–26268. [PMID: 9756849]
[EC 2.4.1.224 created 2002]
 
 
EC 2.4.1.251     Relevance: 14.6%
Accepted name: GlcA-β-(1→2)-D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphospho-ditrans,octacis-undecaprenol 4-β-mannosyltransferase
Reaction: GDP-mannose + GlcA-β-(1→2)-D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphospho-ditrans,octacis-undecaprenol = GDP + D-Man-β-(1→4)- GlcA-β-(1→2)-D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphospho-ditrans,octacis-undecaprenol
Other name(s): GumI
Systematic name: GDP-mannose:GlcA-β-(1→2)-D-Man-α-(1→3)-D-Glc-β-(1→4)-D-Glc-α-1-diphospho-ditrans,octacis-undecaprenol 4-β-mannosyltransferase
Comments: The enzyme is involved in the biosynthesis of the exopolysaccharide xanthan.
References:
1.  Katzen, F., Ferreiro, D.U., Oddo, C.G., Ielmini, M.V., Becker, A., Puhler, A. and Ielpi, L. Xanthomonas campestris pv. campestris gum mutants: effects on xanthan biosynthesis and plant virulence. J. Bacteriol. 180 (1998) 1607–1617. [PMID: 9537354]
2.  Ielpi, L., Couso, R.O. and Dankert, M.A. Sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in Xanthomonas campestris. J. Bacteriol. 175 (1993) 2490–2500. [PMID: 7683019]
3.  Kim, S.Y., Kim, J.G., Lee, B.M. and Cho, J.Y. Mutational analysis of the gum gene cluster required for xanthan biosynthesis in Xanthomonas oryzae pv oryzae. Biotechnol. Lett. 31 (2009) 265–270. [PMID: 18854951]
[EC 2.4.1.251 created 2011]
 
 
EC 2.4.1.141     Relevance: 14.6%
Accepted name: N-acetylglucosaminyldiphosphodolichol N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + N-acetyl-α-D-glucosaminyl-diphosphodolichol = UDP + N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphosphodolichol
Glossary: N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-α-D-glucosaminyl-diphosphodolichol = N,N′-diacetylchitobiosyl-diphosphodolichol
Other name(s): UDP-GlcNAc:dolichyl-pyrophosphoryl-GlcNAc GlcNAc transferase; uridine diphosphoacetylglucosamine-dolichylacetylglucosamine pyrophosphate acetylglucosaminyltransferase; N,N′-diacetylchitobiosylpyrophosphoryldolichol synthase; UDP-N-acetyl-D-glucosamine:N-acetyl-D-glucosaminyl-diphosphodolichol N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:N-acetyl-α-D-glucosaminyl-diphosphodolichol 4-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
References:
1.  Sharma, C.B., Lehle, L. and Tanner, W. Solubilization and characterization of the initial enzymes of the dolichol pathway from yeast. Eur. J. Biochem. 126 (1982) 319–325. [PMID: 6215245]
2.  Turco, S.J. and Heath, E.C. Glucuronosyl-N-acetylglucosaminyl pyrophosphoryldolichol. Formation in SV40-transformed human lung fibroblasts and biosynthesis in rat lung microsomal preparations. J. Biol. Chem. 252 (1977) 2918–2928. [PMID: 192724]
[EC 2.4.1.141 created 1984]
 
 
EC 3.1.3.12     Relevance: 14.6%
Accepted name: trehalose-phosphatase
Reaction: α,α-trehalose 6-phosphate + H2O = α,α-trehalose + phosphate
Other name(s): trehalose 6-phosphatase; trehalose 6-phosphate phosphatase; trehalose-6-phosphate phosphohydrolase
Systematic name: α,α-trehalose-6-phosphate phosphohydrolase
References:
1.  Cabib, E. and Leloir, L.F. The biosynthesis of trehalose phosphate. J. Biol. Chem. 231 (1958) 259–275. [PMID: 13538966]
2.  Candy, D.J. and Kilby, B.A. The biosynthesis of trehalose in the locust fat body. Biochem. J. 78 (1961) 531–536. [PMID: 13690400]
[EC 3.1.3.12 created 1961]
 
 
EC 2.7.9.4     Relevance: 14.5%
Accepted name: α-glucan, water dikinase
Reaction: ATP + α-glucan + H2O = AMP + phospho-α-glucan + phosphate
Other name(s): starch-related R1 protein; GWD
Systematic name: ATP:α-glucan, water phosphotransferase
Comments: Requires Mg2+. ATP appears to be the only phosphate donor. No activity could be detected using GTP, UTP, phosphoenolpyruvate or diphosphate [1]. The protein phosphorylates glucans exclusively on O-6 of glucosyl residues [2]. The protein phosphorylates itself with the β-phosphate of ATP, which is then transferred to the glucan [1].
References:
1.  Ritte, G., Lloyd, J.R., Eckermann, N., Rottmann, A., Kossmann, J. and Steup, M. The starch-related R1 protein is an α-glucan, water dikinase. Proc. Natl. Acad. Sci. USA 99 (2002) 7166–7171. [PMID: 12011472]
2.  Ritte, G., Heydenreich, M., Mahlow, S., Haebel, S., Kötting, O. and Steup, M. Phosphorylation of C6- and C3-positions of glucosyl residues in starch is catalysed by distinct dikinases. FEBS Lett. 580 (2006) 4872–4876. [PMID: 16914145]
[EC 2.7.9.4 created 2002]
 
 
EC 4.4.1.33     Relevance: 14.5%
Accepted name: R-phycocyanin α-cysteine-84 phycourobilin lyase/isomerase
Reaction: [R-phycocyanin α-subunit]-Cys84-phycourobilin = apo-[R-phycocyanin α-subunit] + (2R,3E)-phycoerythrobilin
Other name(s): rpcG (gene name)
Systematic name: [R-phycocyanin α-subunit]-Cys84-phycourobilin:(2R,3E)-phycoerythrobilin lyase/isomerase
Comments: The enzyme, characterized from the cyanobacterium Synechococcus sp. WH8102, catalyses the covalent attachment of the phycobilin chromophore phycoerythrobilin to cysteine 84 of the α subunit of the phycobiliprotein R-phycocyanin and its isomerization to phycourobilin.
References:
1.  Blot, N., Wu, X.J., Thomas, J.C., Zhang, J., Garczarek, L., Bohm, S., Tu, J.M., Zhou, M., Ploscher, M., Eichacker, L., Partensky, F., Scheer, H. and Zhao, K.H. Phycourobilin in trichromatic phycocyanin from oceanic cyanobacteria is formed post-translationally by a phycoerythrobilin lyase-isomerase. J. Biol. Chem. 284 (2009) 9290–9298. [PMID: 19182270]
[EC 4.4.1.33 created 2015]
 
 
EC 2.4.2.38     Relevance: 14.5%
Accepted name: glycoprotein 2-β-D-xylosyltransferase
Reaction: UDP-α-D-xylose + N4-{β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-L-asparaginyl-[protein] = UDP + N4-{β-D-GlcNAc-(1→2)-α-D-Man-(1→3)-[β-D-GlcNAc-(1→2)-α-D-Man-(1→6)]-[β-D-Xyl-(1→2)]-β-D-Man-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-L-asparaginyl-[protein]
Other name(s): β1,2-xylosyltransferase; UDP-D-xylose:glycoprotein (D-xylose to the 3,6-disubstituted mannose of 4-N-{N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→6)]-β-D-mannosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-β-D-glucosaminyl}asparagine) 2-β-D-xylosyltransferase; UDP-D-xylose:glycoprotein (D-xylose to the 3,6-disubstituted mannose of N4-{N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→2)-α-D-mannosyl-(1→6)]-β-D-mannosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→4)-N-acetyl-β-D-glucosaminyl}asparagine) 2-β-D-xylosyltransferase
Systematic name: UDP-α-D-xylose:N4-{β-D-GlcNAc-(1→2)-α-D-mannosyl-(1→3)-[β-D-GlcNAc-(1→2)-α-D-mannosyl-(1→6)]-β-D-mannosyl-(1→4)-β-D-GlcNAc-(1→4)-β-D-GlcNAc}-L-asparaginyl-[protein] 2-β-D-xylosyltransferase (configuration-inverting)
Comments: Specific for N-linked oligosaccharides (N-glycans).
References:
1.  Zeng, Y., Bannon, G., Thomas, V.H., Rice, K., Drake, R. and Elbein, A. Purification and specificity of β1,2-xylosyltransferase, an enzyme that contributes to the allergenicity of some plant proteins. J. Biol. Chem. 272 (1997) 31340–31347. [PMID: 9395463]
2.  Strasser, R., Mucha, J., Mach, L., Altmann, F., Wilson, I.B., Glössl, J. and Steinkellner, H. Molecular cloning and functional expression of β1,2-xylosyltransferase cDNA from Arabidopsis thaliana. FEBS Lett. 472 (2000) 105–108. [PMID: 10781814]
[EC 2.4.2.38 created 2001]
 
 
EC 2.4.1.288     Relevance: 14.5%
Accepted name: galactofuranosylgalactofuranosylrhamnosyl-N-acetylglucosaminyl-diphospho-decaprenol β-1,5/1,6-galactofuranosyltransferase
Reaction: 28 UDP-α-D-galactofuranose + β-D-galactofuranosyl-(1→5)-β-D-galactofuranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans,octacis-decaprenol = 28 UDP + [β-D-galactofuranosyl-(1→5)-β-D-galactofuranosyl-(1→6)]14-β-D-galactofuranosyl-(1→5)-β-D-galactofuranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans,octacis-decaprenol
Other name(s): GlfT2
Systematic name: UDP-α-D-galactofuranose:β-D-galactofuranosyl-(1→5)-β-D-galactofuranosyl-(1→4)-α-L-rhamnopyranosyl-(1→3)-N-acetyl-α-D-glucosaminyl-diphospho-trans,octacis-decaprenol 4-β/5-β-D-galactofuranosyltransferase
Comments: Isolated from Mycobacterium tuberculosis. The enzyme adds approximately twenty-eight galactofuranosyl residues with alternating 1→5 and 1→6 links forming a galactan domain with approximately thirty galactofuranosyl residues. Involved in the formation of the cell wall in mycobacteria.
References:
1.  Rose, N.L., Zheng, R.B., Pearcey, J., Zhou, R., Completo, G.C. and Lowary, T.L. Development of a coupled spectrophotometric assay for GlfT2, a bifunctional mycobacterial galactofuranosyltransferase. Carbohydr. Res. 343 (2008) 2130–2139. [PMID: 18423586]
2.  May, J.F., Splain, R.A., Brotschi, C. and Kiessling, L.L. A tethering mechanism for length control in a processive carbohydrate polymerization. Proc. Natl. Acad. Sci. USA 106 (2009) 11851–11856. [PMID: 19571009]
3.  Wheatley, R.W., Zheng, R.B., Richards, M.R., Lowary, T.L. and Ng, K.K. Tetrameric structure of the GlfT2 galactofuranosyltransferase reveals a scaffold for the assembly of mycobacterial Arabinogalactan. J. Biol. Chem. 287 (2012) 28132–28143. [PMID: 22707726]
[EC 2.4.1.288 created 2012]
 
 
EC 2.4.2.57     Relevance: 14.5%
Accepted name: AMP phosphorylase
Reaction: (1) AMP + phosphate = adenine + α-D-ribose 1,5-bisphosphate
(2) CMP + phosphate = cytosine + α-D-ribose 1,5-bisphosphate
(3) UMP + phosphate = uracil + α-D-ribose 1,5-bisphosphate
Other name(s): AMPpase; nucleoside monophosphate phosphorylase; deoA (gene name)
Systematic name: AMP:phosphate α-D-ribosyl 5′-phosphate-transferase
Comments: The enzyme from archaea is involved in AMP metabolism and CO2 fixation through type III RubisCO enzymes. The activity with CMP and UMP requires activation by cAMP [2].
References:
1.  Sato, T., Atomi, H. and Imanaka, T. Archaeal type III RuBisCOs function in a pathway for AMP metabolism. Science 315 (