ExplorEnz: Search Results

Displaying entries 1-50 of 1797.

<< Previous | Next >> Printable version

2.4.1.267

Relevance: 100%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

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. [DOI] [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. [DOI] [PMID: 14517965]

[EC 2.4.1.267 created 2011, modified 2012]

2.4.1.265

Relevance: 98.4%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [PMID: 12480927]

[EC 2.4.1.265 created 2011, modified 2012]

2.4.1.256

Relevance: 96.1%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [PMID: 9597543]

[EC 2.4.1.256 created 2011, modified 2012]

3.2.1.207

Relevance: 93.2%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [PMID: 17933909]

[EC 3.2.1.207 created 2018]

2.4.1.260

Relevance: 90.5%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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:

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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. [DOI] [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]

2.4.1.261

Relevance: 88.6%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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]

3.2.1.106

Relevance: 87.5%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 78413-07-7

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. [DOI] [PMID: 7356331]

[EC 3.2.1.106 created 1984, modified 2018]

2.4.1.259

Relevance: 85.8%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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. [DOI] [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]

2.4.1.383

Relevance: 85.5%

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 4^II-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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI]
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. [DOI] [PMID: 10520265]

[EC 2.4.1.383 created 2021]

3.2.1.28

Relevance: 84%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9025-52-9

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. [DOI] [PMID: 19897915]

[EC 3.2.1.28 created 1961, modified 2012]

3.2.1.130

Relevance: 83.8%

Accepted name:

glycoprotein endo-α-1,2-mannosidase

Reaction:

GlcMan₉GlcNAc₂-[protein] + H₂O = Man₈GlcNAc₂-[protein] (isomer 8A_1,2,3B_1,2) + 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 8A_1,2,3B_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]

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].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 108022-16-8

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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [PMID: 19181540]

[EC 3.2.1.130 created 1990, modified 2017]

2.4.1.309

Relevance: 83.4%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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. [DOI] [PMID: 20418877]

[EC 2.4.1.309 created 2013]

2.4.1.264

Relevance: 82.4%

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

For diagram of xanthan biosynthesis, click here

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).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [PMID: 14736729]

[EC 2.4.1.264 created 2011, modified 2016]

2.4.3.7

Relevance: 82%

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

For diagram of reaction, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 129924-24-9

References:

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]

2.4.1.258

Relevance: 81.9%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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]

3.2.1.55

Relevance: 81.8%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9067-74-7

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. [DOI] [PMID: 5452669]
3.	Kaji, A. and Yoshihara, O. Properties of purified α-L-arabinofuranosidase from Corticium rolfsii. Biochim. Biophys. Acta 250 (1971) 367–371. [DOI] [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. [DOI] [PMID: 18757805]

[EC 3.2.1.55 created 1972, modified 1976 (EC 3.2.1.79 created 1972, incorporated 1976), modified 2013]

2.4.3.10

Relevance: 81.5%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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]

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]

2.4.1.155

Relevance: 81.1%

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]

For diagram of mannosyl-glycoprotein n-acetylglucosaminyltransferases, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 83588-90-3

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. [DOI] [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]

2.4.1.381

Relevance: 81.1%

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 2^III-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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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. [DOI] [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). [DOI] [PMID: 28929089]

[EC 2.4.1.381 created 2021]

2.4.1.101

Relevance: 80.7%

Accepted name:

α-1,3-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase

Reaction:

UDP-N-acetyl-α-D-glucosamine + Man₅GlcNAc₂-[protein] = UDP + Man₅GlcNAc₃-[protein]

For diagram of mannosyl-glycoprotein N-acetylglucosaminyltransferases, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 102576-81-8

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. [DOI] [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. [DOI] [PMID: 11032794]

[EC 2.4.1.101 created 1983, modified 2001 (EC 2.4.1.51 created 1972, part incorporated 1984), modified 2018]

2.4.1.131

Relevance: 80.7%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 74506-43-7

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. [DOI] [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. [DOI] [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]

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]

2.4.1.308

Relevance: 79.9%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [PMID: 20418877]

[EC 2.4.1.308 created 2013]

2.4.1.199

Relevance: 79.8%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 125008-27-7

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]

2.4.1.87

Relevance: 79.2%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 128449-51-4

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)]

2.4.1.145

Relevance: 78.7%

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]

For diagram of mannosyl-glycoprotein N-acetylglucosaminyltransferases, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 86498-16-0

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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [PMID: 20015870]

[EC 2.4.1.145 created 1984, modified 2001 (EC 2.4.1.51 created 1972, part incorporated 1984), modified 2018]

2.4.1.371

Relevance: 78.7%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [PMID: 25422321]

[EC 2.4.1.371 created 2019]

2.4.1.257

Relevance: 78.5%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [PMID: 16878994]

[EC 2.4.1.257 created 2011, modified 2012]

2.4.2.61

Relevance: 78.4%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

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]

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]

2.4.3.1

Relevance: 77.7%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9075-81-4

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]

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]

3.2.1.210

Relevance: 77.4%

Accepted name:

endoplasmic reticulum Man₈GlcNAc₂ 1,2-α-mannosidase

Reaction:

Man₈GlcNAc₂-[protein] (isomer 8A_1,2,3B_1,3) + H₂O = Man₇GlcNAc₂-[protein] (isomer 7A_1,2,3B₃) + D-mannopyranose

Glossary:

Man₈GlcNAc₂-[protein] (isomer 8A_1,2,3B_1,3) = {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 7A_1,2,3B₃) = {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].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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]

2.4.1.132

Relevance: 77.1%

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

For diagram of dolichyltetradecasaccharide biosynthesis, click here

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].

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 81181-76-2

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. [DOI] [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. [DOI] [PMID: 16878994]

[EC 2.4.1.132 created 1984, modified 2011, modified 2012]

3.2.1.190

Relevance: 76.8%

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

For diagram of diosgenin catabolism, click here

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).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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]

2.4.1.143

Relevance: 76.8%

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]

For diagram of mannosyl-glycoprotein N-acetylglucosaminyltransferases, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 105913-04-0

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. [DOI] [PMID: 7635144]

[EC 2.4.1.143 created 1984, modified 2001 (EC 2.4.1.51 created 1972, part incorporated 1984), modified 2018]

2.4.1.201

Relevance: 76.7%

Accepted name:

α-1,6-mannosyl-glycoprotein 4-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)-[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] = 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→4)]-[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]

For diagram of mannosyl-glycoprotein n-acetylglucosaminyltransferases, click here

Other name(s):

MGAT4C (gene name); N-acetylglucosaminyltransferase VI; N-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase VI; uridine diphosphoacetylglucosamine-glycopeptide β-1→4-acetylglucosaminyltransferase VI; mannosyl-glycoprotein β-1,4-N-acetylglucosaminyltransferase; GnTVI; GlcNAc-T VI; UDP-N-acetyl-D-glucosamine:2,6-bis(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→6)-[N-acetyl-β-D-glucosaminyl-(1→2)]-α-D-mannosyl-glycoprotein 4-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)

Comments:

Requires a high concentration of Mn²⁺ for maximal activity. The enzyme, characterized from hen oviduct membranes, participates in the processing of N-glycans in the Golgi apparatus. It transfers GlcNAc in β1-4 linkage to a D-mannose residue that already has GlcNAc residues attached at positions 2 and 6 by β linkages. No homologous enzyme appears to exist in mammals.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 119699-68-2

References:

1.	Brockhausen, I., Hull, E., Hindsgaul, O., Schachter, H., Shah, R.N., Michnick, S.W. and Carver, J.P. Control of glycoprotein synthesis. Detection and characterization of a novel branching enzyme from hen oviduct, UDP-N-acetylglucosamine:GlcNAc β1-6 (GlcNAc β1-2)Man α-R (GlcNAc to Man) β-4-N-acetylglucosaminyltransferase VI. J. Biol. Chem. 264 (1989) 11211–11221. [PMID: 2525556]
2.	Taguchi, T., Ogawa, T., Inoue, S., Inoue, Y., Sakamoto, Y., Korekane, H. and Taniguchi, N. Purification and characterization of UDP-GlcNAc:GlcNAcβ1-6(GlcNAcβ1-2)Manα1-R [GlcNAc to Man]-β1,4-N-acetylglucosaminyltransferase VI from hen oviduct. J. Biol. Chem. 275 (2000) 32598–32602. [DOI] [PMID: 10903319]
3.	Sakamoto, Y., Taguchi, T., Honke, K., Korekane, H., Watanabe, H., Tano, Y., Dohmae, N., Takio, K., Horii, A. and Taniguchi, N. Molecular cloning and expression of cDNA encoding chicken UDP-N-acetyl-D-glucosamine (GlcNAc): GlcNAcβ 1-6(GlcNAcβ 1-2)- manα 1-R[GlcNAc to man]β 1,4N-acetylglucosaminyltransferase VI. J. Biol. Chem. 275 (2000) 36029–36034. [DOI] [PMID: 10962001]

[EC 2.4.1.201 created 1992, modified 2001, modified 2018]

2.4.1.287

Relevance: 76.5%

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

For diagram of galactofuranan biosynthesis, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [PMID: 18055597]

[EC 2.4.1.287 created 2012, modified 2017]

3.2.1.189

Relevance: 76.4%

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

For diagram of diosgenin catabolism, click here

Glossary:

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).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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]

2.4.2.38

Relevance: 76.1%

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]

For diagram of mannosyl-glycoprotein fucosyl and xylosyl transferases, click here

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).

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 141256-56-6

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. [DOI] [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. [DOI] [PMID: 10781814]

[EC 2.4.2.38 created 2001]

2.7.7.69

Relevance: 76.1%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [PMID: 18463094]
6.	Muller-Moule, P. An expression analysis of the ascorbate biosynthesis enzyme VTC2. Plant Mol. Biol. 68 (2008) 31–41. [DOI] [PMID: 18516687]

[EC 2.7.7.69 created 2010, modified 2020]

2.4.1.68

Relevance: 76%

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]

For diagram of mannosyl-glycoprotein fucosyl and xylosyl transferases, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9033-08-3

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. [DOI] [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. [DOI] [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. [DOI] [PMID: 8910378]

[EC 2.4.1.68 created 1972, modified 2002]

2.4.99.25

Relevance: 75.9%

Accepted name:

lipopolysaccharide heptosyltransferase III

Reaction:

ADP-L-glycero-β-D-manno-heptose + an α-Hep-(1→3)-4-O-phospho-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] = ADP + an α-Hep-(1→7)-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 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-D-manno-heptose

Other name(s):

waaQ (gene name); rfaQ (gene name)

Systematic name:

ADP-L-glycero-β-D-manno-heptose:an α-Hep-(1→3)-4-O-phospho-α-Hep-(1→5)-[α-Kdo-(2→4)]-α-Kdo-(2→6)-[lipid A] heptose^I 7-α-heptosyltransferase

Comments:

The enzyme catalyses a glycosylation step in the biosynthesis of the inner core oligosaccharide of the lipopolysaccharide (endotoxin) of some Gram-negative bacteria.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

References:

1.	Mudapaka, J. and Taylor, E.A. Cloning and characterization of the Escherichia coli heptosyltransferase III: Exploring substrate specificity in lipopolysaccharide core biosynthesis. FEBS Lett. 589 (2015) 1423–1429. [DOI] [PMID: 25957775]

[EC 2.4.99.25 created 2022]

3.2.1.114

Relevance: 75.6%

Accepted name:

mannosyl-oligosaccharide 1,3-1,6-α-mannosidase

Reaction:

Man₅GlcNAc₃-[protein] + 2 H₂O = Man₃GlcNAc₃-[protein] + 2 α-D-mannopyranose

For diagram of mannosyl-glycoprotein n-acetylglucosaminyltransferases, click here

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 82047-77-6

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. [DOI] [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. [DOI] [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. [DOI] [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. [DOI] [PMID: 18599462]
10.	Rose, D.R. Structure, mechanism and inhibition of Golgi α-mannosidase II. Curr. Opin. Struct. Biol. 22 (2012) 558–562. [DOI] [PMID: 22819743]

[EC 3.2.1.114 created 1986, modified 2018]

2.4.1.228

Relevance: 75.5%

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

For diagram of globotetraosylceramide biosynthesis, click here

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 4^II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl(1↔1)ceramide 4^II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4^II-α-D-galactosyltransferase

Systematic name:

UDP-α-D-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4^II-α-D-galactosyltransferase

Comments:

For explanation of superscript II in systematic name, see 2-carb.37.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 52725-57-2

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. [DOI] [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. [DOI] [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. [DOI] [PMID: 10748143]

[EC 2.4.1.228 created 2002]

2.4.2.42

Relevance: 75.4%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc

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. [DOI] [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. [DOI] [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]

2.4.2.62

Relevance: 75.1%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB

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]

2.4.1.223

Relevance: 75%

Accepted name:

glucuronosyl-galactosyl-proteoglycan 4-α-N-acetylglucosaminyltransferase

Reaction:

UDP-N-acetyl-α-D-glucosamine + [protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = UDP + [protein]-3-O-(α-D-GlcNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine

For diagram of heparan biosynthesis (later stages), click here

Glossary:

[protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = [protein]-3-O-(β-D-glucuronosyl-(1→3)-β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine

Other name(s):

α-N-acetylglucosaminyltransferase I; α1,4-N-acetylglucosaminyltransferase; glucuronosylgalactosyl-proteoglycan 4-α-N-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-glucuronosyl-(1→3)-β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl-proteoglycan 4^IV-α-N-acetyl-D-glucosaminyltransferase; glucuronyl-galactosyl-proteoglycan 4-α-N-acetylglucosaminyltransferase

Systematic name:

UDP-N-acetyl-α-D-glucosamine:[protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine 4^IV-α-N-acetyl-D-glucosaminyltransferase (configuration-retaining)

Comments:

Enzyme involved in the initiation of heparin and heparan sulfate synthesis, transferring GlcNAc to the (GlcA-Gal-Gal-Xyl-)Ser core. Apparently products of both the human EXTL2 and EXTL3 genes can catalyse this reaction. In Caenorhabditis elegans, the product of the rib-2 gene displays this activity as well as that of EC 2.4.1.224, glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-α-N-acetylglucosaminyltransferase. For explanation of the use of a superscript in the systematic name, see 2-Carb-37.2.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 179241-74-8

References:

1.	Kitagawa, H., Shimakawa, H. and Sugahara, K. The tumor suppressor EXT-like gene EXTL2 encodes an α1,4-N-acetylhexosaminyltransferase that transfers N-acetylgalactosamine and N-acetylglucosamine to the common glycosaminoglycan-protein linkage region. The key enzyme for the chain initiation of heparan sulfate. J. Biol. Chem. 274 (1999) 13933–13937. [DOI] [PMID: 10318803]
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. [DOI] [PMID: 11121397]

[EC 2.4.1.223 created 2002, modified 2016]

2.4.1.165

Relevance: 74.7%

Accepted name:

N-acetylneuraminylgalactosylglucosylceramide β-1,4-N-acetylgalactosaminyltransferase

Reaction:

UDP-N-acetyl-α-D-galactosamine + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide

For diagram of ganglioside biosynthesis, click here

Other name(s):

uridine diphosphoacetylgalactosamine-acetylneuraminyl(α2→3)galactosyl(β1→4)glucosyl β1→4-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-2,3-α-D-galactosyl-1,4-β-D-glucosylceramide β-1,4-N-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-(2→3)-α-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide 4-β-N-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-(2→3)-α-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-N-acetylgalactosaminyltransferase

Systematic name:

UDP-N-acetyl-α-D-galactosamine:α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-N-acetylgalactosaminyltransferase

Comments:

Requires Mn²⁺. Only substances containing sialic acid residues can act as acceptors; bovine fetuin is the best acceptor tested.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 109136-50-7

References:

1.	Chien, J.-L., Williams, T. and Basu, S. Biosynthesis of a globoside-type glycosphingolipid by a β-N-acetylgalactosaminyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1778–1785. [PMID: 4632917]
2.	Piller, F., Blanchard, D., Huet, M. and Cartron, J.-P. Identification of a α-NeuAc-(2-3)-β-D-galactopyranosyl N-acetyl-β-D-galactosaminyltransferase in human kidney. Carbohydr. Res. 149 (1986) 171–184. [DOI] [PMID: 2425965]
3.	Takeya, A., Hosomi, O. and Kogure, T. Identification and characterization of UDP-GalNAc: NeuAc α2-3Gal β1-4Glc(NAc) β1-4(GalNAc to Gal)N-acetylgalactosaminyltransferase in human blood plasma. J. Biochem. (Tokyo) 101 (1987) 251–259. [PMID: 3106337]

[EC 2.4.1.165 created 1989]

1.3.3.10

Relevance: 74.6%

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.

Links to other databases:

BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 156859-19-7

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. [DOI] [PMID: 7559518]

[EC 1.3.3.10 created 2000 as EC 1.4.3.17, transferred 2003 to EC 1.3.3.10]