Accepted name: hexose oxidase
Reaction: D-glucose + O2 = D-glucono-1,5-lactone + H2O2
Systematic name: D-hexose:oxygen 1-oxidoreductase
Comments: A copper glycoprotein. Also oxidizes D-galactose, D-mannose, maltose, lactose and cellobiose.
1.  Bean, R.C. and Hassid, W.Z. Carbohydrate oxidase from a red alga Iridophycus flaccidum. J. Biol. Chem. 218 (1956) 425–436. [PMID: 13278350]
2.  Bean, R.C., Porter, G.G. and Steinberg, B.M. Carbohydrate metabolism of citrus fruit. II. Oxidation of sugars by an aerodehydrogenase from young orange fruit. J. Biol. Chem. 236 (1961) 1235–1240. [PMID: 13688220]
3.  Sullivan, J.D. and Ikawa, M. Purification and characterization of hexose oxidase from the red alga Chondrus crispus. Biochim. Biophys. Acta 309 (1973) 11–22. [PMID: 4708670]
[EC created 1961, modified 1976]
Accepted name: soluble quinoprotein glucose dehydrogenase
Reaction: D-glucose + acceptor = D-glucono-1,5-lactone + reduced acceptor
Other name(s): soluble glucose dehydrogenase; sGDH; glucose dehydrogenase (PQQ-dependent)
Systematic name: D-glucose:acceptor oxidoreductase
Comments: Soluble periplasmic enzyme containing PQQ as prosthetic group, bound to a calcium ion. Electron acceptor is not known. It is assayed with Wurster’s Blue or phenazine methosulfate. It has negligible sequence or structure similarity to other quinoproteins. It catalyses an exceptionally high rate of oxidation of a wide range of aldose sugars, including D-glucose, galactose, arabinose and xylose, and also the disaccharides lactose, cellobiose and maltose. It has been described only in Acinetobacter calcoaceticus.
1.  Geiger, O. and Gorisch, H. Crystalline quinoprotein glucose dehydrogenase from Acinetobacter calcoaceticus. Biochemistry 25 (1986) 6043–6048.
2.  Dokter, P., Frank, J. and Duine, J.A. Purification and characterization of quinoprotein glucose dehydrogenase from Acinetobacter calcoaceticus L.M.D. 79.41. Biochem. J. 239 (1986) 163–167. [PMID: 3800975]
3.  Cleton-Jansen, A.M., Goosen, N., Wenzel, T.J. and van de Putte, P. Cloning of the gene encoding quinoprotein glucose dehydrogenase from Acinetobacter calcoaceticus: evidence for the presence of a second enzyme. J. Bacteriol. 170 (1988) 2121–2125. [PMID: 2834325]
4.  Matsushita, K., Shinagawa, E., Adachi, O. and Ameyama, M. Quinoprotein D-glucose dehydrogenase of the Acinetobacter calcoaceticus respiratory chain: membrane-bound and soluble forms are different molecular species. Biochemistry 28 (1989) 6276–6280. [PMID: 2551369]
5.  Oubrie, A. and Dijkstra, B.W. Structural requirements of pyrroloquinoline quinone dependent enzymatic reactions. Protein Sci. 9 (2000) 1265–1273. [PMID: 10933491]
6.  Matsushita, K., Toyama, H., Ameyama, M., Adachi, O., Dewanti, A. and Duine, J.A. Soluble and membrane-bound quinoprotein D-glucose dehydrogenases of the Acinetobacter calcoaceticus : the binding process of PQQ to the apoenzymes. Biosci. Biotechnol. Biochem. 59 (1995) 1548–1555.
[EC created 2010]
Accepted name: maltose O-acetyltransferase
Reaction: acetyl-CoA + maltose = CoA + 6-O-acetyl-α-D-glucopyranosyl-(1→4)-D-glucose
Other name(s): maltose transacetylase; maltose O-acetyltransferase; MAT
Systematic name: acetyl-CoA:maltose O-acetyltransferase
Comments: Not identical with EC, galactoside O-acetyltransferase. The acetyl group is added exclusively to the C6 position of glucose and to the C6 position of the non-reducing glucose residue of maltose [3]. Other substrates of this enzyme are glucose, which is a better substrate than maltose [2], and mannose and frucose, which are poorer substrates than maltose [2]. Isopropyl-β-thio-galactose, which is a good substrate for EC is a poor substrate for this enzyme [3].
1.  Freundlieb, S. and Boos, W. Maltose transacetylase of Escherichia coli: a preliminary report. Ann. Microbiol. (Paris) 133A (1982) 181–189. [PMID: 7041741]
2.  Brand, B. and Boos, W. Maltose transacetylase of Escherichia coli. Mapping and cloning of its structural, gene, mac, and characterization of the enzyme as a dimer of identical polypeptides with a molecular weight of 20,000. J. Biol. Chem. 266 (1991) 14113–14118. [PMID: 1856235]
3.  Lo Leggio, L., Dal Degan, F., Poulsen, P., Andersen, S.M. and Larsen, S. The structure and specificity of Escherichia coli maltose acetyltransferase give new insight into the LacA family of acyltransferases. Biochemistry 42 (2003) 5225–5235. [PMID: 12731863]
[EC created 1984]
Deleted entry:  maltose 3-glycosyltransferase
[EC created 1961, deleted 1972]
Accepted name: maltose phosphorylase
Reaction: maltose + phosphate = D-glucose + β-D-glucose 1-phosphate
Systematic name: maltose:phosphate 1-β-D-glucosyltransferase
1.  Doudoroff, M. Disaccharide phosphorylases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 5, Academic Press, New York, 1961, pp. 229–236.
2.  Fitting, C. and Doudoroff, M. Phosphorolysis of maltose by enzyme preparations from Neisseria meningitidis. J. Biol. Chem. 199 (1952) 153–163. [PMID: 12999827]
3.  Putman, E.W., Litt, C.F. and Hassid, W.Z. The structure of D-glucose-D-xylose synthesized by maltose phosphorylase. J. Am. Chem. Soc. 77 (1955) 4351–4353.
4.  Wood, B.J.B. and Rainbow, C. The maltophosphorylase of beer lactobacilli. Biochem. J. 78 (1961) 204–209. [PMID: 13786484]
[EC created 1961]
Accepted name: maltose synthase
Reaction: 2 α-D-glucose 1-phosphate + H2O = maltose + 2 phosphate
Systematic name: α-D-glucose-1-phosphate:α-D-glucose-1-phosphate 4-α-D-glucosyltransferase (dephosphorylating)
Comments: Neither free phosphate nor maltose 1-phosphate is an intermediate in the reaction.
1.  Schilling, N. Characterization of maltose biosynthesis from α-D-glucose-1-phosphate in Spinacia oleracea L. Planta 154 (1982) 87–93. [PMID: 24275923]
[EC created 1984]
Accepted name: oligosaccharide 4-α-D-glucosyltransferase
Reaction: Transfers the non-reducing terminal α-D-glucose residue from a (1→4)-α-D-glucan to the 4-position of a free glucose or of a glucosyl residue at the non-reducing terminus of a (1→4)-α-D-glucan, thus bringing about the rearrangement of oligosaccharides
Other name(s): amylase III; 1,4-α-glucan:1,4-α-glucan 4-α-glucosyltransferase; 1,4-α-D-glucan:1,4-α-D-glucan 4-α-D-glucosyltransferase; α-1,4-transglucosylase
Systematic name: (1→4)-α-D-glucan:(1→4)-α-D-glucan 4-α-D-glucosyltransferase
Comments: The enzyme acts on amylose, amylopectin, glycogen and maltooligosaccharides. No detectable free glucose is formed, indicating the enzyme does not act as a hydrolase. The enzyme from the bacterium Cellvibrio japonicus has the highest activity with maltotriose as a donor, and also accepts maltose [3], while the enzyme from amoeba does not accept maltose [1,2]. Oligosaccharides with 1→6 linkages cannot function as donors, but can act as acceptors [3]. Unlike EC, 4-α-glucanotransferase, this enzyme can transfer only a single glucosyl residue.
1.  Nebinger, P. Separation and characterization of four different amylases of Entamoeba histolytica. I. Purification and properties. Biol. Chem. Hoppe-Seyler 367 (1986) 161–167. [PMID: 2423097]
2.  Nebinger, P. Separation and characterization of four different amylases of Entamoeba histolytica. II. Characterization of amylases. Biol. Chem. Hoppe-Seyler 367 (1986) 169–176. [PMID: 2423098]
3.  Larsbrink, J., Izumi, A., Hemsworth, G.R., Davies, G.J. and Brumer, H. Structural enzymology of Cellvibrio japonicus Agd31B protein reveals α-transglucosylase activity in glycoside hydrolase family 31. J. Biol. Chem. 287 (2012) 43288–43299. [PMID: 23132856]
[EC created 1989, modified 2013]
Accepted name: kojibiose phosphorylase
Reaction: 2-α-D-glucosyl-D-glucose + phosphate = D-glucose + β-D-glucose 1-phosphate
Systematic name: 2-α-D-glucosyl-D-glucose:phosphate β-D-glucosyltransferase
Comments: The enzyme from Thermoanaerobacter brockii can act with α-1,2-oligoglucans, such as selaginose, as substrate, but more slowly. The enzyme is inactive when dissaccharides with linkages other than α-1,2 linkages, such as sophorose, trehalose, neotrehalose, nigerose, laminaribiose, maltose, cellobiose, isomaltose, gentiobiose, sucrose and lactose, are used as substrates.
1.  Chaen, H., Yamamoto, T., Nishimoto, T., Nakada, T., Fukuda, S., Sugimoto, T., Kurimoto, M. and Tsujisaka, Y. Purification and characterization of a novel phosphorylase, kojibiose phosphorylase, from Thermoanaerobium brockii. J. Appl. Glycosci. 46 (1999) 423–429.
2.  Chaen, H., Nishimoto, T., Nakada, T., Fukuda, S., Kurimoto, M. and Tsujisaka, Y. Enzymatic synthesis of kojioligosaccharides using kojibiose phosphorylase. J. Biosci. Bioeng. 92 (2001) 177–182. [PMID: 16233080]
[EC created 2003]
Accepted name: α,α-trehalose synthase
Reaction: NDP-α-D-glucose + D-glucose = α,α-trehalose + NDP
Glossary: NDP = a nucleoside diphosphate
Other name(s): trehalose synthase; trehalose synthetase; UDP-glucose:glucose 1-glucosyltransferase; TreT; PhGT; ADP-glucose:D-glucose 1-α-D-glucosyltransferase
Systematic name: NDP-α-D-glucose:D-glucose 1-α-D-glucosyltransferase
Comments: Requires Mg2+ for maximal activity [1]. The enzyme-catalysed reaction is reversible [1]. In the reverse direction to that shown above, the enzyme is specific for α,α-trehalose as substrate, as it cannot use α- or β-paranitrophenyl glucosides, maltose, sucrose, lactose or cellobiose [1]. While the enzymes from the thermophilic bacterium Rubrobacter xylanophilus and the hyperthermophilic archaeon Pyrococcus horikoshii can use ADP-, UDP- and GDP-α-D-glucose to the same extent [2,3], that from the hyperthermophilic archaeon Thermococcus litoralis has a marked preference for ADP-α-D-glucose [1] and that from the hyperthermophilic archaeon Thermoproteus tenax has a marked preference for UDP-α-D-glucose [4].
1.  Qu, Q., Lee, S.J. and Boos, W. TreT, a novel trehalose glycosyltransferring synthase of the hyperthermophilic archaeon Thermococcus litoralis. J. Biol. Chem. 279 (2004) 47890–47897. [PMID: 15364950]
2.  Ryu, S.I., Park, C.S., Cha, J., Woo, E.J. and Lee, S.B. A novel trehalose-synthesizing glycosyltransferase from Pyrococcus horikoshii: molecular cloning and characterization. Biochem. Biophys. Res. Commun. 329 (2005) 429–436. [PMID: 15737605]
3.  Nobre, A., Alarico, S., Fernandes, C., Empadinhas, N. and da Costa, M.S. A unique combination of genetic systems for the synthesis of trehalose in Rubrobacter xylanophilus: properties of a rare actinobacterial TreT. J. Bacteriol. 190 (2008) 7939–7946. [PMID: 18835983]
4.  Kouril, T., Zaparty, M., Marrero, J., Brinkmann, H. and Siebers, B. A novel trehalose synthesizing pathway in the hyperthermophilic Crenarchaeon Thermoproteus tenax: the unidirectional TreT pathway. Arch. Microbiol. 190 (2008) 355–369. [PMID: 18483808]
[EC created 2008, modified 2013]
Accepted name: N,N′-diacetylchitobiose phosphorylase
Reaction: N,N′-diacetylchitobiose + phosphate = N-acetyl-D-glucosamine + N-acetyl-α-D-glucosamine 1-phosphate
Glossary: N,N′-diacetylchitobiose = N-acetyl-D-glucosaminyl-β-(1→4)-N-acetyl-D-glucosamine
Other name(s): chbP (gene name)
Systematic name: N,N′-diacetylchitobiose:phosphate N-acetyl-D-glucosaminyltransferase
Comments: The enzyme is specific for N,N′-diacetylchitobiose and does not phosphorylate other N-acetylchitooligosaccharides, cellobiose, trehalose, lactose, maltose or sucrose.
1.  Park, J.K., Keyhani, N.O. and Roseman, S. Chitin catabolism in the marine bacterium Vibrio furnissii. Identification, molecular cloning, and characterization of a N,N′-diacetylchitobiose phosphorylase. J. Biol. Chem. 275 (2000) 33077–33083. [PMID: 10913116]
2.  Honda, Y., Kitaoka, M. and Hayashi, K. Reaction mechanism of chitobiose phosphorylase from Vibrio proteolyticus: identification of family 36 glycosyltransferase in Vibrio. Biochem. J. 377 (2004) 225–232. [PMID: 13678418]
3.  Hidaka, M., Honda, Y., Kitaoka, M., Nirasawa, S., Hayashi, K., Wakagi, T., Shoun, H. and Fushinobu, S. Chitobiose phosphorylase from Vibrio proteolyticus, a member of glycosyl transferase family 36, has a clan GH-L-like (α/α)6 barrel fold. Structure 12 (2004) 937–947. [PMID: 15274915]
[EC created 2012]
Accepted name: 3-O-α-D-glucosyl-L-rhamnose phosphorylase
Reaction: 3-O-α-D-glucopyranosyl-L-rhamnopyranose + phosphate = L-rhamnopyranose + β-D-glucose 1-phosphate
Other name(s): cphy1019 (gene name)
Systematic name: 3-O-α-D-glucopyranosyl-L-rhamnopyranose:phosphate β-D-glucosyltransferase
Comments: The enzyme does not phosphorylate α,α-trehalose, kojibiose, nigerose, or maltose. In the reverse phosphorolysis reaction the enzyme is specific for L-rhamnose as acceptor and β-D-glucose 1-phosphate as donor.
1.  Nihira, T., Nakai, H. and Kitaoka, M. 3-O-α-D-glucopyranosyl-L-rhamnose phosphorylase from Clostridium phytofermentans. Carbohydr. Res. 350 (2012) 94–97. [PMID: 22277537]
[EC created 2012]
Accepted name: α-maltose-1-phosphate synthase
Reaction: ADP-α-D-glucose + α-D-glucose-1-phosphate = ADP + α-maltose-1-phosphate
Glossary: maltose = α-D-glucopyranosyl-(1→4)-D-glucose
Other name(s): glgM (gene name)
Systematic name: ADP-α-D-glucose:α-D-glucose-1-phosphate 4-α-D-glucosyltransferase (configuration-retaining)
Comments: The enzyme, found in Mycobacteria, can also use UDP-α-D-glucose with much lower catalytic efficiency.
1.  Koliwer-Brandl, H., Syson, K., van de Weerd, R., Chandra, G., Appelmelk, B., Alber, M., Ioerger, T.R., Jacobs, W.R., Jr., Geurtsen, J., Bornemann, S. and Kalscheuer, R. Metabolic network for the biosynthesis of intra- and extracellular α-glucans required for virulence of Mycobacterium tuberculosis. PLoS Pathog. 12 (2016) e1005768. [PMID: 27513637]
[EC created 2016]
Accepted name: starch synthase (maltosyl-transferring)
Reaction: α-maltose 1-phosphate + [(1→4)-α-D-glucosyl]n = phosphate + [(1→4)-α-D-glucosyl]n+2
Other name(s): α1,4-glucan:maltose-1-P maltosyltransferase; GMPMT
Systematic name: α-maltose 1-phosphate:(1→4)-α-D-glucan 4-α-D-maltosyltransferase
Comments: The enzyme from the bacterium Mycobacterium smegmatis is specific for maltose. It has no activity with α-D-glucose.
1.  Elbein, A.D., Pastuszak, I., Tackett, A.J., Wilson, T. and Pan, Y.T. Last step in the conversion of trehalose to glycogen: a mycobacterial enzyme that transfers maltose from maltose 1-phosphate to glycogen. J. Biol. Chem. 285 (2010) 9803–9812. [PMID: 20118231]
2.  Syson, K., Stevenson, C.E., Rejzek, M., Fairhurst, S.A., Nair, A., Bruton, C.J., Field, R.A., Chater, K.F., Lawson, D.M. and Bornemann, S. Structure of Streptomyces maltosyltransferase GlgE, a homologue of a genetically validated anti-tuberculosis target. J. Biol. Chem. 286 (2011) 38298–38310. [PMID: 21914799]
[EC created 2012]
Transferred entry: protein-Nπ-phosphohistidine—sugar phosphotransferase, now covered by EC protein-Nπ-phosphohistidine—D-mannose phosphotransferase, EC protein-Nπ-phosphohistidine—N-acetylmuramate phosphotransferase, EC protein-Nπ-phosphohistidine—N-acetyl-D-glucosamine phosphotransferase, EC protein-Nπ-phosphohistidine—L-ascorbate phosphotransferase, EC protein-Nπ-phosphohistidine—2-O-α-mannosyl-D-glycerate phosphotransferase, EC protein-Nπ-phosphohistidine—N,N′-diacetylchitobiose phosphotransferase, EC protein-Nπ-phosphohistidine—D-mannitol phosphotransferase, EC protein-Nπ-phosphohistidine—D-sorbitol phosphotransferase, EC protein-Nπ-phosphohistidine—D-glucose phosphotransferase, EC protein-Nπ-phosphohistidine—galactitol phosphotransferase, EC protein-Nπ-phosphohistidine—trehalose phosphotransferase, EC protein-Nπ-phosphohistidine—D-fructose phosphotransferase, EC protein-Nπ-phosphohistidine—D-glucosaminate phosphotransferase, EC protein-Nπ-phosphohistidine—D-galactose phosphotransferase, EC protein-Nπ-phosphohistidine—D-cellobiose phosphotransferase, EC protein-Nπ-phosphohistidine—L-sorbose phosphotransferase, EC protein-Nπ-phosphohistidine—lactose phosphotransferase and EC protein-Nπ-phosphohistidine—maltose phosphotransferase.
[EC created 1972, modified 2000, deleted 2016]
Accepted name: maltokinase
Reaction: ATP + maltose = ADP + α-maltose 1-phosphate
Systematic name: ATP:α-maltose 1-phosphotransferase
Comments: Requires Mg2+ for activity.
1.  Mendes, V., Maranha, A., Lamosa, P., da Costa, M.S. and Empadinhas, N. Biochemical characterization of the maltokinase from Mycobacterium bovis BCG. BMC Biochem. 11:21 (2010). [PMID: 20507595]
[EC created 2012]
Accepted name: protein-Nπ-phosphohistidine—maltose phosphotransferase
Reaction: [protein]-Nπ-phospho-L-histidine + maltose[side 1] = [protein]-L-histidine + maltose 6′-phosphate[side 2]
Other name(s): malT (gene name); maltose PTS permease; EIIMal; Enzyme IIMal
Systematic name: protein-Nπ-phospho-L-histidine:maltose Nπ-phosphotransferase
Comments: This enzyme is a component (known as enzyme II) of a phosphoenolpyruvate (PEP)-dependent, sugar transporting phosphotransferase system (PTS). The system, which is found only in prokaryotes, simultaneously transports its substrate from the periplasm or extracellular space into the cytoplasm and phosphorylates it. The phosphate donor, which is shared among the different systems, is a phospho-carrier protein of low molecular mass that has been phosphorylated by EC (phosphoenolpyruvate—protein phosphotransferase). Enzyme II, on the other hand, is specific for a particular substrate, although in some cases alternative substrates can be transported with lower efficiency. The reaction involves a successive transfer of the phosphate group to several amino acids within the enzyme before the final transfer to the substrate.
1.  Robrish, S.A., Fales, H.M., Gentry-Weeks, C. and Thompson, J. Phosphoenolpyruvate-dependent maltose:phosphotransferase activity in Fusobacterium mortiferum ATCC 25557: specificity, inducibility, and product analysis. J. Bacteriol. 176 (1994) 3250–3256. [PMID: 8195080]
2.  Webb, A.J., Homer, K.A. and Hosie, A.H. A phosphoenolpyruvate-dependent phosphotransferase system is the principal maltose transporter in Streptococcus mutans. J. Bacteriol. 189 (2007) 3322–3327. [PMID: 17277067]
[EC created 1972 as EC, part transferred 2016 to EC]
Accepted name: maltose 6′-phosphate phosphatase
Reaction: maltose 6′-phosphate + H2O = maltose + phosphate
Other name(s): maltose 6′-P phosphatase; mapP (gene name)
Systematic name: maltose 6′-phosphate phosphohydrolase
Comments: The enzyme from the bacterium Enterococcus faecalis also has activity with the sucrose isomer turanose 6′-phosphate (α-D-glucopyranosyl-(1→3)-D-fructose 6-phosphate).
1.  Mokhtari, A., Blancato, V.S., Repizo, G.D., Henry, C., Pikis, A., Bourand, A., de Fatima Alvarez, M., Immel, S., Mechakra-Maza, A., Hartke, A., Thompson, J., Magni, C. and Deutscher, J. Enterococcus faecalis utilizes maltose by connecting two incompatible metabolic routes via a novel maltose 6′-phosphate phosphatase (MapP). Mol. Microbiol. 88 (2013) 234–253. [PMID: 23490043]
[EC created 2013]
Accepted name: β-amylase
Reaction: Hydrolysis of (1→4)-α-D-glucosidic linkages in polysaccharides so as to remove successive maltose units from the non-reducing ends of the chains
Other name(s): saccharogen amylase; glycogenase; β amylase; 1,4-α-D-glucan maltohydrolase
Systematic name: 4-α-D-glucan maltohydrolase
Comments: Acts on starch, glycogen and related polysaccharides and oligosaccharides producing β-maltose by an inversion. The term ‘β’' relates to the initial anomeric configuration of the free sugar group released and not to the configuration of the linkage hydrolysed.
1.  Balls, A.K., Walden, M.K. and Thompson, R.R. A crystalline β-amylase from sweet potatoes. J. Biol. Chem. 173 (1948) 9–19. [PMID: 18902365]
2.  French, D. β-Amylases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 4, Academic Press, New York, 1960, pp. 345–368.
3.  Manners, D.J. Enzymic synthesis and degradation of starch and glycogen. Adv. Carbohydr. Chem. 17 (1962) 371–430.
[EC created 1961]
Accepted name: oligo-1,6-glucosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in some oligosaccharides produced from starch and glycogen by EC (α-amylase), and in isomaltose
Other name(s): limit dextrinase (erroneous); isomaltase; sucrase-isomaltase; exo-oligo-1,6-glucosidase; dextrin 6α-glucanohydrolase; α-limit dextrinase; dextrin 6-glucanohydrolase; oligosaccharide α-1,6-glucohydrolase; α-methylglucosidase
Systematic name: oligosaccharide 6-α-glucohydrolase
Comments: This enzyme, like EC (amylo-α-1,6-glucosidase), can release an α-1→6-linked glucose, whereas the shortest chain that can be released by EC (pullulanase), EC (limit dextrinase), and EC (isoamylase) is maltose. It also hydrolyses isomaltulose (palatinose), isomaltotriose and panose, but has no action on glycogen or phosphorylase limit dextrin. The enzyme from intestinal mucosa is a single polypeptide chain that also catalyses the reaction of EC (sucrose α-glucosidase). Differs from EC (amylo-α-1,6-glucosidase) in its preference for short-chain substrates and in its not requiring the 6-glucosylated residue to be at a branch point, i.e. linked at both C-1 and C-4.
1.  Hauri, H.-P., Quaroni, A. and Isselbacher, K.J. Biogenesis of intestinal plasma membrane: posttranslational route and cleavage of sucrase-isomaltase. Proc. Natl. Acad. Sci. USA 76 (1979) 5183–5186. [PMID: 291933]
2.  Sjöström, H., Norén, O., Christiansen, L., Wacker, H. and Semenza, G. A fully active, two-active-site, single-chain sucrase-isomaltase from pig small intestine. Implications for the biosynthesis of a mammalian integral stalked membrane protein. J. Biol. Chem. 255 (1980) 11332–11338. [PMID: 7002920]
3.  Rodriguez, I.R., Taravel, F.R. and Whelan, W.J. Characterization and function of pig intestinal sucrase-isomaltase and its separate subunits. Eur. J. Biochem. 143 (1984) 575–582. [PMID: 6479163]
4.  Khan, N.A. and Eaton, N.R. Purification and characterization of maltase and α-methyl glucosidase from yeast. Biochim. Biophys. Acta 146 (1967) 173–180. [PMID: 6060462]
5.  Yamamoto, K., Nakayama, A., Yamamoto, Y. and Tabata, S. Val216 decides the substrate specificity of α-glucosidase in Saccharomyces cerevisiae. Eur. J. Biochem. 271 (2004) 3414–3420. [PMID: 15291818]
[EC created 1961, modified 2000, modified 2013]
Accepted name: pullulanase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in pullulan, amylopectin and glycogen, and in the α- and β-limit dextrins of amylopectin and glycogen
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Other name(s): limit dextrinase (erroneous); amylopectin 6-glucanohydrolase; bacterial debranching enzyme; debranching enzyme; α-dextrin endo-1,6-α-glucosidase; R-enzyme; pullulan α-1,6-glucanohydrolase
Systematic name: pullulan 6-α-glucanohydrolase
Comments: Different from EC (limit dextrinase) in its action on glycogen, and its rate of hydrolysis of limit dextrins. Its action on amylopectin is complete. Maltose is the smallest sugar that it can release from an α-(1→6)-linkage.
1.  Lee, E.Y.C. and Whelan, W.J. Glycogen and starch debranching enzymes. In: Boyer, P.D. (Ed.), The Enzymes, 3rd edn, vol. 5, Academic Press, New York, 1972, pp. 191–234.
2.  Bender, H. and Wallenfels, K. Pullulanase (an amylopectin and glycogen debranching enzyme) from Aerobacter aerogenes. Methods Enzymol. 8 (1966) 555–559.
3.  Manners, D.J. Observations on the specificity and nomenclature of starch debranching enzymes. J. Appl. Glycosci. 44 (1997) 83–85.
[EC created 1972, modified 1976, modified 2000 (EC created 1972, incorporated 1976)]
Accepted name: sucrose α-glucosidase
Reaction: Hydrolysis of sucrose and maltose by an α-D-glucosidase-type action
Other name(s): sucrose α-glucohydrolase; sucrase; sucrase-isomaltase; sucrose.α.-glucohydrolase; intestinal sucrase; sucrase(invertase)
Systematic name: sucrose-α-D-glucohydrolase
Comments: This enzyme is isolated from intestinal mucosa as a single polypeptide chain that also displays activity towards isomaltose (EC oligo-1,6-glucosidase).
1.  Conklin, K.A., Yamashiro, K.M. and Gray, G.M. Human intestinal sucrase-isomaltase. Identification of free sucrase and isomaltase and cleavage of the hybrid into active distinct subunits. J. Biol. Chem. 250 (1975) 5735–5741. [PMID: 807575]
2.  Hauri, H.-P., Quaroni, A. and Isselbacher, K.J. Biogenesis of intestinal plasma membrane: posttranslational route and cleavage of sucrase-isomaltase. Proc. Natl. Acad. Sci. USA 76 (1979) 5183–5186. [PMID: 291933]
3.  Kolinska, J. and Kraml, J. Separation and characterization of sucrose-isomaltase and of glucoamylase of rat intestine. Biochim. Biophys. Acta 284 (1972) 235–247. [PMID: 5073761]
4.  Sigrist, H., Ronner, P. and Semenza, G. A hydrophobic form of the small-intestinal sucrase-isomaltase complex. Biochim. Biophys. Acta 406 (1975) 433–446. [PMID: 1182172]
5.  Sjöström, H., Norén, O., Christiansen, L., Wacker, H. and Semenza, G. A fully active, two-active-site, single-chain sucrase-isomaltase from pig small intestine. Implications for the biosynthesis of a mammalian integral stalked membrane protein. J. Biol. Chem. 255 (1980) 11332–11338. [PMID: 7002920]
6.  Takesue, Y. Purification and properties of rabbit intestinal sucrase. J. Biochem. (Tokyo) 65 (1969) 545–552. [PMID: 5804876]
[EC created 1972]
Accepted name: isopullulanase
Reaction: Hydrolysis of pullulan to isopanose (6-α-maltosylglucose)
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Systematic name: pullulan 4-glucanohydrolase (isopanose-forming)
Comments: The enzyme has practically no action on starch. Panose (4-α-isomaltosylglucose) is hydrolysed to isomaltose and glucose. cf. EC (pullulanase) and EC (neopullulanase).
1.  Sakano, Y., Masuda, N. and Kobayashi, T. Hydrolysis of pullulan by a novel enzyme from Aspergillus niger. Agric. Biol. Chem. 35 (1971) 971–973.
[EC created 1972]
Accepted name: glucan 1,4-α-maltotetraohydrolase
Reaction: Hydrolysis of (1→4)-α-D-glucosidic linkages in amylaceous polysaccharides, to remove successive maltotetraose residues from the non-reducing chain ends
Other name(s): exo-maltotetraohydrolase; 1,4-α-D-glucan maltotetraohydrolase
Systematic name: 4-α-D-glucan maltotetraohydrolase
Comments: Compare EC β-amylase, which removes successive maltose residues, and EC (glucan 1,4-α-maltohexaosidase) and EC (glucan 1,4-α-maltotriohydrolase).
1.  Nakakuki, T., Azuma, K. and Kainuma, K. Action patterns of various exo-amylases and the anomeric configurations of their products. Carbohydr. Res. 128 (1984) 297–310.
2.  Robyt, J.F. and Ackerman, R.J. Isolation, purification, and characterization of a maltotetraose-producing amylase from Pseudomonas stutzeri. Arch. Biochem. Biophys. 145 (1971) 105–114. [PMID: 5123132]
[EC created 1972]
Accepted name: isoamylase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic branch linkages in glycogen, amylopectin and their β-limit dextrins
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Other name(s): debranching enzyme; glycogen α-1,6-glucanohydrolase
Systematic name: glycogen 6-α-D-glucanohydrolase
Comments: Also readily hydrolyses amylopectin. Differs from EC (pullulanase) and EC (limit dextrinase) by its inability to hydrolyse pullulan, and by limited action on α-limit dextrins. Maltose is the smallest sugar it can release from an α-(1→6)-linkage.
1.  Yokobayashi, K., Misaki, A. and Harada, T. Purification and properties of Pseudomonas isoamylase. Biochim. Biophys. Acta 212 (1970) 458–469. [PMID: 5456995]
[EC created 1972, modified 1976, modified 2000]
Accepted name: glucan 1,6-α-glucosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in (1→6)-α-D-glucans and derived oligosaccharides
Other name(s): exo-1,6-β-glucosidase; glucodextrinase; glucan α-1,6-D-glucohydrolase
Systematic name: glucan 6-α-D-glucohydrolase
Comments: Hydrolysis is accompanied by inversion at C-1, so that new reducing ends are released in the β-configuration. Dextrans and isomaltosaccharides are hydrolysed, as is isomaltose, but very slowly. The enzyme from some sources also possesses the activity of EC (glucan endo-1,3-α-glucosidase).
1.  Ohya, T., Sawai, T., Uemura, S. and Abe, K. Some catalytic properties of an exo-1,6-α-glucosidase (glucodextranase) from Arthrobacter globiformis I42. Agric. Biol. Chem. 42 (1978) 571–577.
2.  Sawai, T., Yamaki, T. and Ohya, T. Preparation and some properties of Arthrobacter globiformis exo-1,6-α-glucosidase. Agric. Biol. Chem. 40 (1976) 1293–1299.
3.  Walker, G.J. and Pulkownik, A. Degradation of dextrans by an α-1,6-glucan glucohydrolase from Streptococcus mitis. Carbohydr. Res. 29 (1973) 1–14. [PMID: 4356399]
[EC created 1972, modified 2001]
Accepted name: glucan 1,6-α-isomaltosidase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in polysaccharides, to remove successive isomaltose units from the non-reducing ends of the chains
Other name(s): exo-isomaltohydrolase; isomalto-dextranase; isomaltodextranase; G2-dextranase; 1,6-α-D-glucan isomaltohydrolase
Systematic name: 6-α-D-glucan isomaltohydrolase
Comments: Optimum activity is on those 1,6-α-D-glucans containing 6, 7 and 8 glucose units; those containing 3, 4 and 5 glucose units are hydrolysed at slower rates.
1.  Sawai, T., Toriyama, K. and Yano, K. A bacterial dextranase releasing only isomaltose from dextrans. J. Biochem. (Tokyo) 75 (1974) 105–112. [PMID: 4826536]
2.  Sawai, T. and Niwa, Y. Transisomaltosylation activity of a bacterial isomaltodextranase. Agric. Biol. Chem. 39 (1975) 1077–1083.
[EC created 1976]
Accepted name: glucan 1,4-α-maltohexaosidase
Reaction: Hydrolysis of (1→4)-α-D-glucosidic linkages in amylaceous polysaccharides, to remove successive maltohexaose residues from the non-reducing chain ends
Other name(s): exo-maltohexaohydrolase; 1,4-α-D-glucan maltohexaohydrolase
Systematic name: 4-α-D-glucan maltohexaohydrolase
Comments: cf. EC glucan 1,4-α-glucosidase, which removes successive glucose residues; EC β-amylase, which removes successive maltose residues; EC glucan 1,4-α-maltotriohydrolase, which removes successive maltotriose units and EC glucan 1,4-α-maltotetraohydrolase, which removes successive maltotetraose residues. The products have the α-configuration.
1.  Kainuma, K., Wako, K., Kobayashi, A., Nogami, A. and Suzuki, S. Purification and some properties of a novel maltohexaose-producing exo-amylase from Aerobacter aerogenes. Biochim. Biophys. Acta 410 (1975) 333–346. [PMID: 1094]
2.  Nakakuki, T., Azuma, K. and Kainuma, K. Action patterns of various exo-amylases and the anomeric configurations of their products. Carbohydr. Res. 128 (1984) 297–310.
[EC created 1978]
Accepted name: maltose-6′-phosphate glucosidase
Reaction: α-maltose 6′-phosphate + H2O = D-glucose + D-glucose 6-phosphate
Other name(s): phospho-α-glucosidase; maltose-6′-phosphate 6-phosphoglucohydrolase
Systematic name: α-maltose-6′-phosphate 6-phosphoglucohydrolase
Comments: Hydrolyses a variety of 6-phospho-α-D-glucosides, including α-maltose 6′-phosphate, α,α-trehalose 6-phosphate, sucrose 6-phosphate and p-nitrophenyl-α-D-glucopyranoside 6-phosphate (as a chromogenic substrate). The enzyme is activated by FeII, MnII, CoII and NiII. It is rapidly inactivated in air.
1.  Thompson, J., Gentry-Weeks, C.R., Nguyen, N.Y., Folk, J.E., Robrish, S.A. Purification from Fusobacterium mortiferum ATCC 25557 of a 6-phosphoryl-O-α-D-glucopyranosyl:6-phosphoglucohydrolase that hydrolyses maltose 6-phosphate and related phospho-α-D-glucosides. J. Bacteriol. 177 (1995) 2505–2512. [PMID: 7730284]
[EC created 1989, modified 1999]
Accepted name: glucan 1,4-α-maltohydrolase
Reaction: hydrolysis of (1→4)-α-D-glucosidic linkages in polysaccharides so as to remove successive α-maltose residues from the non-reducing ends of the chains
Other name(s): maltogenic α-amylase; 1,4-α-D-glucan α-maltohydrolase
Systematic name: 4-α-D-glucan α-maltohydrolase
Comments: Acts on starch and related polysaccharides and oligosaccharides. The product is α-maltose; cf. EC β-amylase.
1.  Diderichsen, B. and Christiansen, L. Cloning of a maltogenic α-amylase from Bacillus stearothermophilus. FEMS Microbiol. Lett. 56 (1988) 53–59.
2.  Outtrup, H. and Norman, B.E. Properties and application of a thermostable maltogenic amylase produced by a strain of Bacillus modified by recombinant-DNA techniques. Stärke 36 (1984) 405–411.
[EC created 1992, modified 1999]
Accepted name: neopullulanase
Reaction: Hydrolysis of pullulan to panose (6-α-D-glucosylmaltose)
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Other name(s): pullulanase II
Systematic name: pullulan 4-D-glucanohydrolase (panose-forming)
Comments: cf. EC (pullulanase ) and EC (isopullulanase).
1.  Imanaka, T. and Kuriki, T. Pattern of action of Bacillus stearothermophilus neopullulanase on pullulan. J. Bacteriol. 171 (1989) 369–374. [PMID: 2914851]
[EC created 1992]
Accepted name: limit dextrinase
Reaction: Hydrolysis of (1→6)-α-D-glucosidic linkages in α- and β-limit dextrins of amylopectin and glycogen, and in amylopectin and pullulan
Glossary: pullulan = a linear polymer of (1→6)-linked maltotriose units
Other name(s): R-enzyme; amylopectin-1,6-glucosidase; dextrin α-1,6-glucanohydrolase
Systematic name: dextrin 6-α-glucanohydrolase
Comments: Plant enzymes with little or no action on glycogen. Action on amylopectin is incomplete, but action on α-limit dextrins is complete. Maltose is the smallest sugar it can release from an α-(1→6)-linkage.
1.  Gordon, R.W., Manners, D.J. and Stark, J.R. The limit dextrinase of the broad bean (Vicia faba). Carbohydr. Res. 42 (1975) 125–134.
2.  Manners, D.J. Observations on the specificity and nomenclature of starch debranching enzymes. J. Appl. Glycosci. 44 (1997) 83–85.
[EC created 2000]
Accepted name: 1,3-α-isomaltosidase
Reaction: cyclobis-(1→6)-α-nigerosyl + 2 H2O = 2 isomaltose (overall reaction)
(1a) cyclobis-(1→6)-α-nigerosyl + H2O = α-isomaltosyl-(1→3)-isomaltose
(1b) α-isomaltosyl-(1→3)-isomaltose + H2O = 2 isomaltose
Systematic name: 1,3-α-isomaltohydrolase (configuration-retaining)
Comments: The enzyme, characterized from the bacteria Bacillus sp. NRRL B-21195 and Kribbella flavida, participates in the degradation of starch. The cyclic tetrasaccharide cyclobis-(1→6)-α-nigerosyl is formed from starch extracellularly and imported into the cell, where it is degraded to glucose.
1.  Kim, Y.K., Kitaoka, M., Hayashi, K., Kim, C.H. and Cote, G.L. Purification and characterization of an intracellular cycloalternan-degrading enzyme from Bacillus sp. NRRL B-21195. Carbohydr. Res. 339 (2004) 1179–1184. [PMID: 15063208]
2.  Tagami, T., Miyano, E., Sadahiro, J., Okuyama, M., Iwasaki, T. and Kimura, A. Two novel glycoside hydrolases responsible for the catabolism of cyclobis-(1→6)-α-nigerosyl. J. Biol. Chem. 291 (2016) 16438–16447. [PMID: 27302067]
[EC created 2017]
Accepted name: isomaltose glucohydrolase
Reaction: isomaltose + H2O = β-D-glucose + D-glucose
Systematic name: isomaltose 6-α-glucohydrolase (configuration-inverting)
Comments: The enzyme catalyses the hydrolysis of α-1,6-glucosidic linkages from the non-reducing end of its substrate. Unlike EC, oligo-1,6-glucosidase, the enzyme inverts the anomeric configuration of the released residue. The enzyme can also act on panose and maltotriose at a lower rate.
1.  Tagami, T., Miyano, E., Sadahiro, J., Okuyama, M., Iwasaki, T. and Kimura, A. Two novel glycoside hydrolases responsible for the catabolism of cyclobis-(1→6)-α-nigerosyl. J. Biol. Chem. 291 (2016) 16438–16447. [PMID: 27302067]
[EC created 2017]
Transferred entry: maltose-transporting ATPase. Now EC, ABC-type maltose transporter
[EC created 2000, deleted 2018]
Accepted name: exo-(1→4)-α-D-glucan lyase
Reaction: linear α-glucan = (n-1) 1,5-anhydro-D-fructose + D-glucose
Other name(s): α-(1→4)-glucan 1,5-anhydro-D-fructose eliminase; α-1,4-glucan exo-lyase; α-1,4-glucan lyase; GLase
Systematic name: (1→4)-α-D-glucan exo-4-lyase (1,5-anhydro-D-fructose-forming)
Comments: The enzyme catalyses the sequential degradation of (1→4)-α-D-glucans from the non-reducing end with the release of 1,5-anhydro-D-fructose. Thus, for an α-glucan containing n (1→4)-linked glucose units, the final products are 1 glucose plus (n-1) 1,5-anhydro-D-fructose. Maltose, maltosaccharides and amylose are all completely degraded. It does not degrade (1→6)-α-glucosidic bonds and thus the degradation of a branched glucan, such as amylopectin or glycogen, will result in the formation of 1,5-anhydro-D-fructose plus a limit dextrin. Other enzymes involved in the anhydrofructose pathway are EC (aldos-2-ulose dehydratase), EC (1,5-anhydro-D-fructose dehydratase) and EC (ascopyrone tautomerase).
1.  Yu, S., Kenne, L., Pedersén, M. α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. I. Efficient purification and characterization from red seaweeds. Biochim. Biophys. Acta 1156 (1993) 313–320. [PMID: 8461323]
2.  Yu, S., Pedersén, M. α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. II. Subcellular localization and partial amino-acid sequence. Planta 191 (1993) 137–142. [PMID: 7763826]
3.  Yu, S., Ahmad, T., Kenne, L. and Pedersén, M. α-1,4-Glucan lyase, a new class of starch/glycogen degrading enzyme. III. Substrate specificity, mode of action, and cleavage mechanism. Biochim. Biophys. Acta 1244 (1995) 1–9. [PMID: 7766642]
4.  Yu, S., Christensen, T.M., Kragh, K.M., Bojsen, K. and Marcussen, J. Efficient purification, characterization and partial amino acid sequencing of two α-1,4-glucan lyases from fungi. Biochim. Biophys. Acta 1339 (1997) 311–320. [PMID: 9187252]
5.  Yu, S., Bojsen, K., Svensson, B. and Marcussen, J. α-1,4-glucan lyases producing 1,5-anhydro-D-fructose from starch and glycogen have sequence similarity to α-glucosidases. Biochim. Biophys. Acta 1433 (1999) 1–15. [PMID: 10446355]
6.  Lee, S.S., Yu, S. and Withers, S.G. α-1,4-Glucan lyase performs a trans-elimination via a nucleophilic displacement followed by a syn-elimination. J. Am. Chem. Soc. 124 (2002) 4948–4949. [PMID: 11982345]
7.  Lee, S.S., Yu, S. and Withers, S.G. Detailed dissection of a new mechanism for glycoside cleavage: α-1,4-glucan lyase. Biochemistry 42 (2003) 13081–13090. [PMID: 14596624]
[EC created 1999]
Accepted name: aldose 1-epimerase
Reaction: α-D-glucose = β-D-glucose
Other name(s): mutarotase; aldose mutarotase; galactose mutarotase; galactose 1-epimerase; D-galactose 1-epimerase
Systematic name: aldose 1-epimerase
Comments: Also acts on L-arabinose, D-xylose, D-galactose, maltose and lactose. This enzyme catalyses the first step in galactose metabolism by converting β-D-galactose into α-D-galactose, which is the substrate for EC, galactokinase [5,6].
1.  Bentley, R. and Bhate, D.S. Mutarotase from Penicillium notatum. I. Purification, assay, and general properties of the enzyme. J. Biol. Chem. 235 (1960) 1219–1224. [PMID: 13799037]
2.  Bentley, R. and Bhate, D.S. Mutarotase from Penicillium notatum. II. The mechanism of the mutarotation reaction. J. Biol. Chem. 235 (1960) 1225–1233. [PMID: 13799038]
3.  Keilin, D. and Hartree, E.F. Biological catalysis of mutarotation of glucose. Biochem. J. 50 (1952) 341–348. [PMID: 14915955]
4.  Levy, G.B. and Cook, E.S. A rotographic study of mutarotase. Biochem. J. 57 (1954) 50–55. [PMID: 13159947]
5.  Beebe, J.A. and Frey, P.A. Galactose mutarotase: purification, characterization, and investigations of two important histidine residues. Biochemistry 37 (1998) 14989–14997. [PMID: 9778377]
6.  Thoden, J.B., Timson, D.J., Reece, R.J. and Holden, H.M. Molecular structure of human galactose mutarotase. J. Biol. Chem. 279 (2004) 23431–23437. [PMID: 15026423]
7.  Thoden, J.B., Kim, J., Raushel, F.M. and Holden, H.M. The catalytic mechanism of galactose mutarotase. Protein Sci. 12 (2003) 1051–1059. [PMID: 12717027]
[EC created 1961]
Accepted name: maltose epimerase
Reaction: α-maltose = β-maltose
Systematic name: maltose 1-epimerase
Comments: The enzyme catalyses the interconversion of α and β anomers of maltose more effectively than those of disaccharides such as lactose and cellobiose.
1.  Shirokane, Y. and Suzuki, M. A novel enzyme, maltose 1-epimerase from Lactobacillus brevis IFO 3345. FEBS Lett. 367 (1995) 177–179. [PMID: 7796915]
[EC created 2002]
Accepted name: (1→4)-α-D-glucan 1-α-D-glucosylmutase
Reaction: 4-[(1→4)-α-D-glucosyl]n-1-D-glucose = 1-α-D-[(1→4)-α-D-glucosyl]n-1-α-D-glucopyranoside
Other name(s): malto-oligosyltrehalose synthase; maltodextrin α-D-glucosyltransferase
Systematic name: (1→4)-α-D-glucan 1-α-D-glucosylmutase
Comments: The enzyme from Arthrobacter sp., Sulfolobus acidocaldarius acts on (1→4)-α-D-glucans containing three or more (1→4)-α-linked D-glucose units. Not active towards maltose.
1.  Maruta, K., Nakada, T., Kubota, M., Chaen, H., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Formation of trehalose from maltooligosaccharides by a novel enzymatic system. Biosci. Biotechnol. Biochem. 59 (1995) 1829–1834. [PMID: 8534970]
2.  Nakada, T., Maruta, K., Tsusaki, K., Kubota, M., Chaen, H., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Purification and properties of a novel enzyme, maltooligosyl trehalose synthase, from Arthrobacter sp. Q36. Biosci. Biotechnol. Biochem. 59 (1995) 2210–2214. [PMID: 8611744]
3.  Nakada, T., Ikegami, S., Chaen, H., Kubota, M., Fukuda, S., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Purification and characterization of thermostable maltooligosyl trehalose synthase from the thermoacidophilic archaebacterium Sulfolobus acidocaldarius. Biosci. Biotechnol. Biochem. 60 (1996) 263–266. [PMID: 9063973]
[EC created 1999]
Accepted name: maltose α-D-glucosyltransferase
Reaction: maltose = α,α-trehalose
Other name(s): trehalose synthase; maltose glucosylmutase
Systematic name: maltose α-D-glucosylmutase
1.  Nishimoto, T., Nakano, M., Ikegami, S., Chaen, H., Fukuda, S., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Existence of a novel enzyme converting maltose to trehalose. Biosci. Biotechnol. Biochem. 59 (1995) 2189–2190.
2.  Nishimoto, T., Nakano, M., Nakada, T., Chaen, H., Fukuda, S., Sugimoto, T., Kurimoto, M., Tsujisaka, Y. Purification and properties of a novel enzyme, trehalose synthase, from Pimelobacter sp. R48. Biosci. Biotechnol. Biochem. 60 (1996) 640–644. [PMID: 8829531]
[EC created 1999]
Accepted name: L-cysteine:1D-myo-inositol 2-amino-2-deoxy-α-D-glucopyranoside ligase
Reaction: 1-O-(2-amino-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol + L-cysteine + ATP = 1-O-[2-(L-cysteinamido)-2-deoxy-α-D-glucopyranosyl]-1D-myo-inositol + AMP + diphosphate
Glossary: mycothiol = 1-O-[2-(N2-acetyl-L-cysteinamido)-2-deoxy--D-glucopyranosyl]-1D-myo-inositol
Other name(s): MshC; MshC ligase; Cys:GlcN-Ins ligase; mycothiol ligase
Systematic name: L-cysteine:1-O-(2-amino-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol ligase (AMP-forming)
Comments: This enzyme is a key enzyme in the biosynthesis of mycothiol, a small molecular weight thiol found in Mycobacteria spp. and other actinomycetes. Mycothiol plays a fundamental role in these organisms by helping to provide protection from the effects of reactive oxygen species and electrophiles, including many antibiotics. The enzyme may represent a novel target for new classes of antituberculars [2].
1.  Fan, F., Luxenburger, A., Painter, G.F. and Blanchard, J.S. Steady-state and pre-steady-state kinetic analysis of Mycobacterium smegmatis cysteine ligase (MshC). Biochemistry 46 (2007) 11421–11429. [PMID: 17848100]
2.  Gutierrez-Lugo, M.T., Newton, G.L., Fahey, R.C. and Bewley, C.A. Cloning, expression and rapid purification of active recombinant mycothiol ligase as B1 immunoglobulin binding domain of streptococcal protein G, glutathione-S-transferase and maltose binding protein fusion proteins in Mycobacterium smegmatis. Protein Expr. Purif. 50 (2006) 128–136. [PMID: 16908186]
3.  Tremblay, L.W., Fan, F., Vetting, M.W. and Blanchard, J.S. The 1.6 Å crystal structure of Mycobacterium smegmatis MshC: the penultimate enzyme in the mycothiol biosynthetic pathway. Biochemistry 47 (2008) 13326–13335. [PMID: 19053270]
[EC created 2009]
Accepted name: ABC-type maltose transporter
Reaction: ATP + H2O + maltose-[maltose-binding protein][side 1] = ADP + phosphate + maltose[side 2] + [maltose-binding protein][side 1]
Other name(s): maltose ABC transporter; maltose-transporting ATPase
Systematic name: ATP phosphohydrolase (ABC-type, maltose-importing)
Comments: An ATP-binding cassette (ABC) type transporter, characterized by the presence of two similar ATP-binding domains/proteins and two integral membrane domains/proteins. The enzyme, found in bacteria, interacts with an extracytoplasmic substrate binding protein and mediates the import of maltose and maltose oligosaccharides.
1.  Higgins, C.F. ABC transporters: from microorganisms to man. Annu. Rev. Cell Biol. 8 (1992) 67–113. [PMID: 1282354]
2.  Dassa, E. and Muir, S. Membrane topology of MalG, an inner membrane protein from the maltose transport system of Escherichia coli. Mol. Microbiol. 7 (1993) 29–38. [PMID: 8437518]
3.  Kuan, G., Dassa, E., Saurin, N., Hofnung, M. and Saier, M.H., Jr. Phylogenetic analyses of the ATP-binding constituents of bacterial extracytoplasmic receptor-dependent ABC-type nutrient uptake permeases. Res. Microbiol. 146 (1995) 271–278. [PMID: 7569321]
4.  Saier, M.H., Jr. Molecular phylogeny as a basis for the classification of transport proteins from bacteria, archaea and eukarya. Adv. Microb. Physiol. 40 (1998) 81–136. [PMID: 9889977]
5.  Griffiths, J.K. and Sansom, C.E. The Transporter Factsbook, Academic Press, San Diego, 1998.
[EC created 2000 as EC, transferred 2018 to EC]