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]
Transferred entry: cellobiose oxidase. Now included with EC, cellobiose dehydrogenase (acceptor)
[EC created 1986, deleted 2005]
Deleted entry:  cellobiose dehydrogenase (quinone). Now known to be proteolytic product of EC, cellobiose dehydrogenase (acceptor)
[EC created 1983, deleted 2002]
Accepted name: cellobiose dehydrogenase (acceptor)
Reaction: cellobiose + acceptor = cellobiono-1,5-lactone + reduced acceptor
Other name(s): cellobiose dehydrogenase; cellobiose oxidoreductase; Phanerochaete chrysosporium cellobiose oxidoreductase; CBOR; cellobiose oxidase; cellobiose:oxygen 1-oxidoreductase; CDH; cellobiose:(acceptor) 1-oxidoreductase
Systematic name: cellobiose:acceptor 1-oxidoreductase
Comments: Also acts, more slowly, on cello-oligosaccharides, lactose and D-glucosyl-1,4-β-D-mannose. The enzyme from the white rot fungus Phanerochaete chrysosporium is unusual in having two redoxin domains, one containing a flavin and the other a protoheme group. It transfers reducing equivalents from cellobiose to two types of redox acceptor: two-electron oxidants, including redox dyes, benzoquinones, and molecular oxygen, and one-electron oxidants, including semiquinone species, iron(II) complexes, and the model acceptor cytochrome c [9]. 2,6-Dichloroindophenol can act as acceptor in vitro.
1.  Coudray, M.-R., Canebascini, G. and Meier, H. Characterization of a cellobiose dehydrogenase in the cellulolytic fungus porotrichum (Chrysosporium) thermophile. Biochem. J. 203 (1982) 277–284. [PMID: 7103940]
2.  Dekker, R.F.H. Induction and characterization of a cellobiose dehydrogenase produced by a species of Monilia. J. Gen. Microbiol. 120 (1980) 309–316.
3.  Dekker, R.F.H. Cellobiose dehydrogenase produced by Monilia sp. Methods Enzymol. 160 (1988) 454–463.
4.  Habu, N., Samejima, M., Dean, J.F. and Eriksson, K.E. Release of the FAD domain from cellobiose oxidase by proteases from cellulolytic cultures of Phanerochaete chrysosporium. FEBS Lett. 327 (1993) 161–164. [PMID: 8392950]
5.  Baminger, U., Subramaniam, S.S., Renganathan, V. and Haltrich, D. Purification and characterization of cellobiose dehydrogenase from the plant pathogen Sclerotium (Athelia) rolfsii. Appl. Environ. Microbiol. 67 (2001) 1766–1774. [PMID: 11282631]
6.  Hallberg, B.M., Henriksson, G., Pettersson, G. and Divne, C. Crystal structure of the flavoprotein domain of the extracellular flavocytochrome cellobiose dehydrogenase. J. Mol. Biol. 315 (2002) 421–434. [PMID: 11786022]
7.  Ayers, A.R., Ayers, S.B. and Eriksson, K.-E. Cellobiose oxidase, purification and partial characterization of a hemoprotein from Sporotrichum pulverulentum. Eur. J. Biochem. 90 (1978) 171–181. [PMID: 710416]
8.  Ayers, A.R. and Eriksson, K.-E. Cellobiose oxidase from Sporotrichum pulverulentum. Methods Enzymol. 89 (1982) 129–135. [PMID: 7144569]
9.  Mason, M.G., Nicholls, P., Divne, C., Hallberg, B.M., Henriksson, G. and Wilson, M.T. The heme domain of cellobiose oxidoreductase: a one-electron reducing system. Biochim. Biophys. Acta 1604 (2003) 47–54. [PMID: 12686420]
[EC created 1983, modified 2002 (EC created 1983, incorporated 2002, EC created 1986, incorporated 2005)]
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: lytic cellulose monooxygenase (C1-hydroxylating)
Reaction: [(1→4)-β-D-glucosyl]n+m + reduced acceptor + O2 = [(1→4)-β-D-glucosyl]m-1-(1→4)-D-glucono-1,5-lactone + [(1→4)-β-D-glucosyl]n + acceptor + H2O
Other name(s): lytic polysaccharide monooxygenase (ambiguous); LPMO (ambiguous); LPMO9A
Systematic name: cellulose, hydrogen-donor:oxygen oxidoreductase (D-glucosyl C1-hydroxylating)
Comments: This copper-containing enzyme, found in fungi and bacteria, cleaves cellulose in an oxidative manner. The cellulose fragments that are formed contain a D-glucono-1,5-lactone residue at the reducing end, which hydrolyses quickly and spontaneously to the aldonic acid. The electrons are provided in vivo by the cytochrome b domain of EC, cellobiose dehydrogenase (acceptor) [1]. Ascorbate can serve as the electron donor in vitro.
1.  Phillips, C.M., Beeson, W.T., Cate, J.H. and Marletta, M.A. Cellobiose dehydrogenase and a copper-dependent polysaccharide monooxygenase potentiate cellulose degradation by Neurospora crassa. ACS Chem. Biol. 6 (2011) 1399–1406. [PMID: 22004347]
2.  Beeson, W.T., Phillips, C.M., Cate, J.H. and Marletta, M.A. Oxidative cleavage of cellulose by fungal copper-dependent polysaccharide monooxygenases. J. Am. Chem. Soc. 134 (2012) 890–892. [PMID: 22188218]
3.  Li, X., Beeson, W.T., 4th, Phillips, C.M., Marletta, M.A. and Cate, J.H. Structural basis for substrate targeting and catalysis by fungal polysaccharide monooxygenases. Structure 20 (2012) 1051–1061. [PMID: 22578542]
4.  Bey, M., Zhou, S., Poidevin, L., Henrissat, B., Coutinho, P.M., Berrin, J.G. and Sigoillot, J.C. Cello-oligosaccharide oxidation reveals differences between two lytic polysaccharide monooxygenases (family GH61) from Podospora anserina. Appl. Environ. Microbiol. 79 (2013) 488–496. [PMID: 23124232]
5.  Frommhagen, M., Sforza, S., Westphal, A.H., Visser, J., Hinz, S.W., Koetsier, M.J., van Berkel, W.J., Gruppen, H. and Kabel, M.A. Discovery of the combined oxidative cleavage of plant xylan and cellulose by a new fungal polysaccharide monooxygenase. Biotechnol. Biofuels 8:101 (2015). [PMID: 26185526]
6.  Patel, I., Kracher, D., Ma, S., Garajova, S., Haon, M., Faulds, C.B., Berrin, J.G., Ludwig, R. and Record, E. Salt-responsive lytic polysaccharide monooxygenases from the mangrove fungus Pestalotiopsis sp. NCi6. Biotechnol Biofuels 9:108 (2016). [PMID: 27213015]
7.  Courtade, G., Wimmer, R., Rohr, A.K., Preims, M., Felice, A.K., Dimarogona, M., Vaaje-Kolstad, G., Sorlie, M., Sandgren, M., Ludwig, R., Eijsink, V.G. and Aachmann, F.L. Interactions of a fungal lytic polysaccharide monooxygenase with β-glucan substrates and cellobiose dehydrogenase. Proc. Natl. Acad. Sci. USA 113 (2016) 5922–5927. [PMID: 27152023]
[EC created 2017]
Accepted name: cellobiose phosphorylase
Reaction: cellobiose + phosphate = α-D-glucose 1-phosphate + D-glucose
Systematic name: cellobiose:phosphate α-D-glucosyltransferase
1.  Alexander, J.K. Purification and specificity of cellobiose phosphorylase from Clostridium thermocellum. J. Biol. Chem. 243 (1968) 2899–2904. [PMID: 5653182]
2.  Ayers, W.A. Phosphorolysis and synthesis of cellobiose by cell extracts from Ruminococcus flavefaciens. J. Biol. Chem. 234 (1959) 2819–2822. [PMID: 13795349]
[EC created 1965]
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: β-1,4-mannooligosaccharide phosphorylase
Reaction: [(1→4)-β-D-mannosyl]n + phosphate = [(1→4)-β-D-mannosyl]n-1 + α-D-mannose 1-phosphate
Other name(s): RaMP2
Systematic name: 1,4-β-D-mannooligosaccharide:phosphate α-D-mannosyltransferase
Comments: The enzyme, isolated from the ruminal bacterium Ruminococcus albus, catalyses the reversible phosphorolysis of β-1,4-mannooligosaccharide with a minimum size of three monomers.
1.  Kawahara, R., Saburi, W., Odaka, R., Taguchi, H., Ito, S., Mori, H. and Matsui, H. Metabolic mechanism of mannan in a ruminal bacterium, Ruminococcus albus, involving two mannoside phosphorylases and cellobiose 2-epimerase: discovery of a new carbohydrate phosphorylase, β-1,4-mannooligosaccharide phosphorylase. J. Biol. Chem. 287 (2012) 42389–42399. [PMID: 23093406]
[EC created 2014]
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: β-glucoside kinase
Reaction: ATP + cellobiose = ADP + 6-phospho-β-D-glucosyl-(1→4)-D-glucose
Other name(s): β-D-glucoside kinase (phosphorylating)
Systematic name: ATP:cellobiose 6-phosphotransferase
Comments: Phosphorylates a number of β-D-glucosides; GTP, CTP, ITP and UTP can also act as donors.
1.  Palmer, R.E. and Anderson, R.L. Cellobiose metabolism in Aerobacter aerogenes. II. Phosphorylation of cellobiose with adenosine 5′-triphosphate by a β-glucoside kinase. J. Biol. Chem. 247 (1972) 3415–3419. [PMID: 5030625]
[EC created 1976]
Accepted name: protein-Nπ-phosphohistidine—N,N′-diacetylchitobiose phosphotransferase
Reaction: [protein]-Nπ-phospho-L-histidine + N,N′-diacetylchitobiose[side 1] = [protein]-L-histidine + N,N′-diacetylchitobiose 6′-phosphate[side 2]
Other name(s): chbABC (gene names); N,N′-diacetylchitobiose PTS permease; chitobiose PTS permease; EIIcel; EIIchb; Enzyme IIcel; Enzyme IIchb
Systematic name: protein-Nπ-phospho-L-histidine:N,N′-diacetylchitobiose 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.  Keyhani, N.O., Wang, L.X., Lee, Y.C. and Roseman, S. The chitin disaccharide, N,N′-diacetylchitobiose, is catabolized by Escherichia coli and is transported/phosphorylated by the phosphoenolpyruvate:glycose phosphotransferase system. J. Biol. Chem. 275 (2000) 33084–33090. [PMID: 10913117]
2.  Reizer, J., Reizer, A. and Saier, M.H., Jr. The cellobiose permease of Escherichia coli consists of three proteins and is homologous to the lactose permease of Staphylococcus aureus. Res. Microbiol. 141 (1990) 1061–1067. [PMID: 2092358]
3.  Keyhani, N.O., Boudker, O. and Roseman, S. Isolation and characterization of IIAChb, a soluble protein of the enzyme II complex required for the transport/phosphorylation of N, N′-diacetylchitobiose in Escherichia coli. J. Biol. Chem. 275 (2000) 33091–33101. [PMID: 10913118]
4.  Keyhani, N.O., Bacia, K. and Roseman, S. The transport/phosphorylation of N,N′-diacetylchitobiose in Escherichia coli. Characterization of phospho-IIB(Chb) and of a potential transition state analogue in the phosphotransfer reaction between the proteins IIA(Chb) AND IIB(Chb). J. Biol. Chem. 275 (2000) 33102–33109. [PMID: 10913119]
[EC created 1972 as EC, part transferred 2016 to EC]
Accepted name: protein-Nπ-phosphohistidine—cellobiose phosphotransferase
Reaction: [protein]-Nπ-phospho-L-histidine + cellobiose[side 1] = [protein]-L-histidine + 6-phospho-β-D-glucosyl-(1→4)-D-glucose[side 2]
Other name(s): celB (gene name); cellobiose PTS permease; EIICel; Enzyme IICel
Systematic name: protein-Nπ-phospho-L-histidine:cellobiose 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.  Lai, X. and Ingram, L.O. Cloning and sequencing of a cellobiose phosphotransferase system operon from Bacillus stearothermophilus XL-65-6 and functional expression in Escherichia coli. J. Bacteriol. 175 (1993) 6441–6450. [PMID: 8407820]
2.  Lai, X., Davis, F.C., Hespell, R.B. and Ingram, L.O. Cloning of cellobiose phosphoenolpyruvate-dependent phosphotransferase genes: functional expression in recombinant Escherichia coli and identification of a putative binding region for disaccharides. Appl. Environ. Microbiol. 63 (1997) 355–363. [PMID: 9023916]
3.  Stoll, R. and Goebel, W. The major PEP-phosphotransferase systems (PTSs) for glucose, mannose and cellobiose of Listeria monocytogenes, and their significance for extra- and intracellular growth. Microbiology 156 (2010) 1069–1083. [PMID: 20056707]
4.  Wu, M.C., Chen, Y.C., Lin, T.L., Hsieh, P.F. and Wang, J.T. Cellobiose-specific phosphotransferase system of Klebsiella pneumoniae and its importance in biofilm formation and virulence. Infect. Immun. 80 (2012) 2464–2472. [PMID: 22566508]
[EC created 1972 as EC, part transferred 2016 to EC]
Accepted name: glucan 1,4-β-glucosidase
Reaction: Hydrolysis of (1→4)-linkages in (1→4)-β-D-glucans, to remove successive glucose units
Other name(s): exo-1,4-β-glucosidase; exocellulase; exo-β-1,4-glucosidase; exo-β-1,4-glucanase; β-1,4-β-glucanase; β-glucosidase; exo-1,4-β-glucanase; 1,4-β-D-glucan glucohydrolase
Systematic name: 4-β-D-glucan glucohydrolase
Comments: Acts on 1,4-β-D-glucans and related oligosaccharides. Cellobiose is hydrolysed, but very slowly.
1.  Barras, D.R., Moore, A.E. and Stone, B.A. Enzyme-substrate relations among β-glucan hydrolases. Adv. Chem. Ser. 95 (1969) 105–138.
[EC created 1972]
Accepted name: 6-phospho-β-glucosidase
Reaction: 6-phospho-β-D-glucosyl-(1→4)-D-glucose + H2O = D-glucose + D-glucose 6-phosphate
Other name(s): phospho-β-glucosidase A; phospho-β-glucosidase; phosphocellobiase; 6-phospho-β-D-glucosyl-(1,4)-D-glucose glucohydrolase
Systematic name: 6-phospho-β-D-glucosyl-(1→4)-D-glucose glucohydrolase
Comments: Also hydrolyses several other phospho-β-D-glucosides, but not their non-phosphorylated forms.
1.  Palmer, R.E. and Anderson, R.L. Cellobiose metabolism in Aerobacter aerogenes. 3. Cleavage of cellobiose monophosphate by a phospho-β-glucosidase. J. Biol. Chem. 247 (1972) 3420–3423. [PMID: 4624114]
[EC created 1976]
Accepted name: cellulose 1,4-β-cellobiosidase (non-reducing end)
Reaction: Hydrolysis of (1→4)-β-D-glucosidic linkages in cellulose and cellotetraose, releasing cellobiose from the non-reducing ends of the chains
Other name(s): exo-cellobiohydrolase; β-1,4-glucan cellobiohydrolase; β-1,4-glucan cellobiosylhydrolase; 1,4-β-glucan cellobiosidase; exoglucanase; avicelase; CBH 1; C1 cellulase; cellobiohydrolase I; cellobiohydrolase; exo-β-1,4-glucan cellobiohydrolase; 1,4-β-D-glucan cellobiohydrolase; cellobiosidase
Systematic name: 4-β-D-glucan cellobiohydrolase (non-reducing end)
1.  Berghem, L.E.R. and Pettersson, L.G. The mechanism of enzymatic cellulose degradation. Purification of a cellulolytic enzyme from Trichoderma viride active on highly ordered cellulose. Eur. J. Biochem. 37 (1973) 21–30. [PMID: 4738092]
2.  Eriksson, K.E. and Pettersson, B. Extracellular enzyme system utilized by the fungus Sporotrichum pulverulentum (Chrysosporium lignorum) for the breakdown of cellulose. 3. Purification and physico-chemical characterization of an exo-1,4-β-glucanase. Eur. J. Biochem. 51 (1975) 213–218. [PMID: 235428]
3.  Halliwell, G., Griffin, M. and Vincent, R. The role of component C1 in cellulolytic systems. Biochem. J. 127 (1972) 43P. [PMID: 5076675]
[EC created 1976, modified 2011]
Accepted name: amygdalin β-glucosidase
Reaction: (R)-amygdalin + H2O = (R)-prunasin + D-glucose
Other name(s): amygdalase; amygdalinase; amygdalin hydrolase; amygdalin glucosidase
Systematic name: amygdalin β-D-glucohydrolase
Comments: Highly specific; does not act on prunasin, linamarin, gentiobiose or cellobiose (cf. EC β-glucosidase).
1.  Kuroki, G., Lizotte, P.A. and Poulton, J.E. L-β-Glycosidases from Prunus serotina EHRH and Davallia trichomanoides. Z. Natursforsch. C: Biosci. 39 (1984) 232–239.
[EC created 1989]
Accepted name: vicianin β-glucosidase
Reaction: (R)-vicianin + H2O = mandelonitrile + vicianose
Other name(s): vicianin hydrolase
Systematic name: (R)-vicianin β-D-glucohydrolase
Comments: Also hydrolyses, more slowly, (R)-amygdalin and (R)-prunasin, but not gentiobiose, linamarin or cellobiose.
1.  Kuroki, G., Lizotte, P.A. and Poulton, J.E. L-β-Glycosidases from Prunus serotina EHRH and Davallia trichomanoides. Z. Natursforsch. C: Biosci. 39 (1984) 232–239.
[EC created 1989]
Accepted name: oligoxyloglucan reducing-end-specific cellobiohydrolase
Reaction: Hydrolysis of cellobiose from the reducing end of xyloglucans consisting of a (1→4)-β-linked glucan carrying α-D-xylosyl groups on O-6 of the glucose residues. To be a substrate, the first residue must be unsubstituted, the second residue may bear a xylosyl group, whether further glycosylated or not, and the third residue, which becomes the new terminus by the action of the enzyme, is preferably xylosylated, but this xylose residue must not be further substituted.
Systematic name: oligoxyloglucan reducing-end cellobiohydrolase
Comments: The enzyme is found in the fungus Geotrichum sp. M128. The substrate is a hemicellulose found in plant cell walls.
1.  Yaoi, K. and Mitsuishi, Y. Purification, characterization, cloning, and expression of a novel xyloglucan-specific glycosidase, oligoxyloglucan reducing end-specific cellobiohydrolase. J. Biol. Chem. 277 (2002) 48276–48281. [PMID: 12374797]
[EC created 2003]
Accepted name: cellulose 1,4-β-cellobiosidase (reducing end)
Reaction: Hydrolysis of (1→4)-β-D-glucosidic linkages in cellulose and similar substrates, releasing cellobiose from the reducing ends of the chains.
Other name(s): CelS; CelSS; endoglucanase SS; cellulase SS; cellobiohydrolase CelS; Cel48A
Systematic name: 4-β-D-glucan cellobiohydrolase (reducing end)
Comments: Some exocellulases, most of which belong to the glycoside hydrolase family 48 (GH48, formerly known as cellulase family L), act at the reducing ends of cellulose and similar substrates. The CelS enzyme from Clostridium thermocellum is the most abundant subunit of the cellulosome formed by the organism. It liberates cellobiose units from the reducing end by hydrolysis of the glycosidic bond, employing an inverting reaction mechanism [2]. Different from EC, which attacks cellulose from the non-reducing end.
1.  Barr, B.K., Hsieh, Y.L., Ganem, B. and Wilson, D.B. Identification of two functionally different classes of exocellulases. Biochemistry 35 (1996) 586–592. [PMID: 8555231]
2.  Saharay, M., Guo, H. and Smith, J.C. Catalytic mechanism of cellulose degradation by a cellobiohydrolase, CelS. PLoS One 5:e1294 (2010). [PMID: 20967294]
[EC created 2011]
Accepted name: cellobiose epimerase
Reaction: cellobiose = 4-O-β-D-glucopyranosyl-D-mannose
Glossary: cellobiose = 4-O-β-D-glucopyranosyl-D-glucose
Systematic name: cellobiose 2-epimerase
Comments: The enzyme catalyses the interconversion between D-glucose and D-mannose residues at the reducing end of β-1,4-linked disaccharides by epimerizing the hydroxyl group at the C-2 position of the glucose moiety.
1.  Tyler, T.R. and Leatherwood, J.M. Epimerization of disaccharides by enzyme preparations from Ruminococcus albus. Arch. Biochem. Biophys. 119 (1967) 363–367. [PMID: 6069974]
2.  Ito, S., Taguchi, H., Hamada, S., Kawauchi, S., Ito, H., Senoura, T., Watanabe, J., Nishimukai, M., Ito, S. and Matsui, H. Enzymatic properties of cellobiose 2-epimerase from Ruminococcus albus and the synthesis of rare oligosaccharides by the enzyme. Appl. Microbiol. Biotechnol. 79 (2008) 433–441. [PMID: 18392616]
3.  Fujiwara, T., Saburi, W., Inoue, S., Mori, H., Matsui, H., Tanaka, I. and Yao, M. Crystal structure of Ruminococcus albus cellobiose 2-epimerase: structural insights into epimerization of unmodified sugar. FEBS Lett. 587 (2013) 840–846. [PMID: 23462136]
[EC created 1972]
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]

Data © 2001–2020 IUBMB
Web site © 2005–2020 Andrew McDonald