The Enzyme Database

Displaying entries 51-100 of 1327.

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EC 3.5.1.115     Relevance: 100%
Accepted name: mycothiol S-conjugate amidase
Reaction: a mycothiol S-conjugate + H2O = an N-acetyl L-cysteine-S-conjugate + 1-O-(2-amino-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol
Glossary: mycothiol = 1-O-[2-(N2-acetyl-L-cysteinamido)-2-deoxy-α-D-glucopyranosyl]-1D-myo-inositol
N-acetyl L-cysteine-S-conjugate = mercapturic acid
Other name(s): MCA
Systematic name: mycothiol S-conjugate 1D-myo-inositol 2-amino-2-deoxy-α-D-glucopyranosyl-hydrolase
Comments: The enzyme that is found in actinomycetes is involved in the detoxification of oxidizing agents and electrophilic antibiotics. The enzyme has low activity with 1-O-(2-acetamido-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol as substrate (cf. EC 3.5.1.103, N-acetyl-1-D-myo-inositol-2-amino-2-deoxy-α-D-glucopyranoside deacetylase) [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Newton, G.L., Av-Gay, Y. and Fahey, R.C. A novel mycothiol-dependent detoxification pathway in mycobacteria involving mycothiol S-conjugate amidase. Biochemistry 39 (2000) 10739–10746. [DOI] [PMID: 10978158]
2.  Steffek, M., Newton, G.L., Av-Gay, Y. and Fahey, R.C. Characterization of Mycobacterium tuberculosis mycothiol S-conjugate amidase. Biochemistry 42 (2003) 12067–12076. [DOI] [PMID: 14556638]
[EC 3.5.1.115 created 2013]
 
 
EC 2.4.1.86     Relevance: 100%
Accepted name: N-acetyl-β-D-glucosaminide β-(1,3)-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-β-D-glucosaminyl-R = UDP + β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R
For diagram of lactotetraosylceramide biosynthesis, click here
Other name(s): B3GALT1 (gene name); uridine diphosphogalactose-acetyl-glucosaminylgalactosylglucosylceramide galactosyltransferase; GalT-4; UDP-galactose:N-acetyl-D-glucosaminyl-1,3-D-galactosyl-1,4-D-glucosylceramide β-D-galactosyltransferase; UDP-galactose:N-acetyl-D-glucosaminyl-(1→3)-D-galactosyl-(1→4)-D-glucosylceramide 3-β-D-galactosyltransferase; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosylceramide 3-β-D-galactosyltransferase; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide 3-β-D-galactosyltransferase; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-D-galactosyltransferase; glucosaminylgalactosylglucosylceramide β-galactosyltransferase; UDP-α-D-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-β-D-glucosaminyl-R 3-β-D-galactosyltransferase
Comments: The enzyme transfers galactose from UDP-α-D-galactose to the 3-position of substrates with a non-reducing terminal N-acetyl-β-D-glucosamine (β-GlcNAc) residue. It can act on both glycolipids and glycoproteins, generating a structure known as the type 1 histo-blood group antigen precursor.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9073-46-5
References:
1.  Basu, M. and Basu, S. Enzymatic synthesis of a tetraglycosylceramide by a galactosyltransferase from rabbit bone marrow. J. Biol. Chem. 247 (1972) 1489–1495. [PMID: 4335001]
2.  Basu, M., Presper, K.A., Basu, S., Hoffman, L.M. and Brooks, S.E. Differential activities of glycolipid glycosyltransferases in Tay-Sachs disease: studies in cultured cells from cerebrum. Proc. Natl. Acad. Sci. USA 76 (1979) 4270–4274. [DOI] [PMID: 291963]
3.  Amado, M., Almeida, R., Carneiro, F., Levery, S.B., Holmes, E.H., Nomoto, M., Hollingsworth, M.A., Hassan, H., Schwientek, T., Nielsen, P.A., Bennett, E.P. and Clausen, H. A family of human β3-galactosyltransferases. Characterization of four members of a UDP-galactose:β-N-acetyl-glucosamine/β-nacetyl-galactosamine β-1,3-galactosyltransferase family. J. Biol. Chem. 273 (1998) 12770–12778. [DOI] [PMID: 9582303]
4.  Amado, M., Almeida, R., Schwientek, T. and Clausen, H. Identification and characterization of large galactosyltransferase gene families: galactosyltransferases for all functions. Biochim. Biophys. Acta 1473 (1999) 35–53. [DOI] [PMID: 10580128]
5.  Bardoni, A., Valli, M. and Trinchera, M. Differential expression of β1,3galactosyltransferases in human colon cells derived from adenocarcinomas or normal mucosa. FEBS Lett. 451 (1999) 75–80. [DOI] [PMID: 10356986]
[EC 2.4.1.86 created 1976, modified 2017]
 
 
EC 2.4.99.5      
Transferred entry: galactosyldiacylglycerol α-2,3-sialyltransferase. Now EC 2.4.3.5, galactosyldiacylglycerol α-2,3-sialyltransferase
[EC 2.4.99.5 created 1984, modified 1986, deleted 2022]
 
 
EC 2.4.3.5     Relevance: 99.9%
Accepted name: galactosyldiacylglycerol α-2,3-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + 1,2-diacyl-3-β-D-galactosyl-sn-glycerol = CMP + 1,2-diacyl-3-[3-(N-acetyl-α-D-neuraminyl)-β-D-galactosyl]-sn-glycerol
Systematic name: CMP-N-acetyl-β-neuraminate:1,2-diacyl-3-β-D-galactosyl-sn-glycerol N-acetylneuraminyltransferase
Comments: The β-D-galactosyl residue of the oligosaccharide of glycoproteins may also act as acceptor.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 80237-98-5
References:
1.  Pieringer, J., Keech, S. and Pieringer, R.A. Biosynthesis in vitro of sialosylgalactosyldiacylglycerol by mouse brain microsomes. J. Biol. Chem. 256 (1981) 12306–12309. [PMID: 7298658]
2.  Weinstein, J., de Souza-e-Silva, U. and Paulson, J.C. Purification of a Gal β1→4GlcNAc α2→6 sialyltransferase and a Gal β1→3(4)GlcNAc α2→3 sialyltransferase to homogeneity from rat liver. J. Biol. Chem. 257 (1982) 13835–13844. [PMID: 7142179]
3.  Weinstein, J., de Souza-e-Silva, U. and Paulson, J.C. Sialylation of glycoprotein oligosaccharides N-linked to asparagine. Enzymatic characterization of a Gal β1→3(4)GlcNAc α2→3 sialyltransferase and a Gal β1→4GlcNAc α2→6 sialyltransferase from rat liver. J. Biol. Chem. 257 (1982) 13845–13853. [PMID: 7142180]
[EC 2.4.3.5 created 1984 as EC 2.4.99.5, modified 1986, transferred 2022 to EC 2.4.3.5]
 
 
EC 3.2.1.97     Relevance: 99.9%
Accepted name: endo-α-N-acetylgalactosaminidase
Reaction: β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-[glycoprotein]-L-serine/L-threonine + H2O = β-D-galactosyl-(1→3)-N-acetyl-D-galactosamine + [glycoprotein]-L-serine/L-threonine
Other name(s): endo-α-acetylgalactosaminidase; endo-α-N-acetyl-D-galactosaminidase; mucinaminylserine mucinaminidase; D-galactosyl-3-(N-acetyl-α-D-galactosaminyl)-L-serine mucinaminohydrolase; endo-α-GalNAc-ase; glycopeptide α-N-acetylgalactosaminidase; D-galactosyl-N-acetyl-α-D-galactosamine D-galactosyl-N-acetyl-galactosaminohydrolase
Systematic name: glycopeptide-D-galactosyl-N-acetyl-α-D-galactosamine D-galactosyl-N-acetyl-galactosaminohydrolase
Comments: The enzyme catalyses the liberation of Gal-(1→3)-β-GalNAc α-linked to serine or threonine residues of mucin-type glycoproteins. EngBF from the bacterium Bifidobacterium longum specifically acts on core 1-type O-glycan to release the disaccharide Gal-(1→3)-β-GalNAc. The enzymes from the bacteria Clostridium perfringens, Enterococcus faecalis, Propionibacterium acnes and Alcaligenes faecalis show broader specificity (e.g. they can also release the core 2 trisaccharide Gal-(1→3)-β-(GlcNAc-(1→6)-β)-GalNAc or the core 3 disaccharide GlcNAc-(1→3)-β-GalNAc) [1,2]. The enzyme may play an important role in the degradation and utilization of mucins having core 1 O-glycan.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 59793-96-3
References:
1.  Ashida, H., Maki, R., Ozawa, H., Tani, Y., Kiyohara, M., Fujita, M., Imamura, A., Ishida, H., Kiso, M. and Yamamoto, K. Characterization of two different endo-α-N-acetylgalactosaminidases from probiotic and pathogenic enterobacteria, Bifidobacterium longum and Clostridium perfringens. Glycobiology 18 (2008) 727–734. [DOI] [PMID: 18559962]
2.  Koutsioulis, D., Landry, D. and Guthrie, E.P. Novel endo-α-N-acetylgalactosaminidases with broader substrate specificity. Glycobiology 18 (2008) 799–805. [DOI] [PMID: 18635885]
3.  Fujita, K., Oura, F., Nagamine, N., Katayama, T., Hiratake, J., Sakata, K., Kumagai, H. and Yamamoto, K. Identification and molecular cloning of a novel glycoside hydrolase family of core 1 type O-glycan-specific endo-α-N-acetylgalactosaminidase from Bifidobacterium longum. J. Biol. Chem. 280 (2005) 37415–37422. [DOI] [PMID: 16141207]
4.  Suzuki, R., Katayama, T., Kitaoka, M., Kumagai, H., Wakagi, T., Shoun, H., Ashida, H., Yamamoto, K. and Fushinobu, S. Crystallographic and mutational analyses of substrate recognition of endo-α-N-acetylgalactosaminidase from Bifidobacterium longum. J. Biochem. 146 (2009) 389–398. [DOI] [PMID: 19502354]
5.  Gregg, K.J. and Boraston, A.B. Cloning, recombinant production, crystallization and preliminary X-ray diffraction analysis of a family 101 glycoside hydrolase from Streptococcus pneumoniae. Acta Crystallogr. Sect. F Struct. Biol. Cryst. Commun. 65 (2009) 133–135. [DOI] [PMID: 19194003]
6.  Ashida, H., Yamamoto, K., Murata, T., Usui, T. and Kumagai, H. Characterization of endo-α-N-acetylgalactosaminidase from Bacillus sp. and syntheses of neo-oligosaccharides using its transglycosylation activity. Arch. Biochem. Biophys. 373 (2000) 394–400. [DOI] [PMID: 10620364]
7.  Goda, H.M., Ushigusa, K., Ito, H., Okino, N., Narimatsu, H. and Ito, M. Molecular cloning, expression, and characterization of a novel endo-α-N-acetylgalactosaminidase from Enterococcus faecalis. Biochem. Biophys. Res. Commun. 375 (2008) 441–446. [DOI] [PMID: 18725192]
[EC 3.2.1.97 created 1978 (EC 3.2.1.110 created 1984, incorporated 2008), modified 2008, modified 2011]
 
 
EC 2.4.99.10      
Transferred entry: neolactotetraosylceramide α-2,3-sialyltransferase. Now included in EC 2.4.3.6, N-acetyllactosaminide α-2,3-sialyltransferase
[EC 2.4.99.10 created 1986, deleted 2017]
 
 
EC 2.4.1.223     Relevance: 99.7%
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 4IV-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 4IV-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]
 
 
EC 2.4.1.156     Relevance: 99.5%
Accepted name: indolylacetyl-myo-inositol galactosyltransferase
Reaction: UDP-α-D-galactose + (indol-3-yl)acetyl-myo-inositol = UDP + 5-O-(indol-3-yl)acetyl-myo-inositol D-galactoside
Other name(s): uridine diphosphogalactose-indolylacetylinositol galactosyltransferase; indol-3-ylacetyl-myo-inositol galactoside synthase; UDP-galactose:indol-3-ylacetyl-myo-inositol 5-O-D-galactosyltransferase; UDP-galactose:(indol-3-yl)acetyl-myo-inositol 5-O-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:(indol-3-yl)acetyl-myo-inositol 5-O-D-galactosyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 85537-80-0
References:
1.  Corcuera, L.J., Michalczuk, L. and Bandurski, R.S. Enzymic synthesis of indol-3-ylacetyl-myo-inositol galactoside. Biochem. J. 207 (1982) 283–290. [PMID: 7159382]
[EC 2.4.1.156 created 1986]
 
 
EC 2.4.1.370     Relevance: 99.2%
Accepted name: inositol phosphorylceramide mannosyltransferase
Reaction: GDP-α-D-mannose + a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-[(1D-myo-inositol-1-O-yl)hydroxyphosphoryl]sphinganine = a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-{[6-O-(α-D-mannosyl)-1D-myo-inositol-1-O-yl]hydroxyphosphoryl}sphinganine + GDP
Glossary: a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-[(1D-myo-inositol-1-O-yl)hydroxyphosphoryl]sphinganine = a very-long-chain inositol phospho-α hydroxyphytoceramide = IPC
a (4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-{[6-O-(α-D-mannosyl)-1D-myo-inositol-1-O-yl]hydroxyphosphoryl}sphinganine = a very-long-chain mannosylinositol phospho-α-hydroxyphytoceramide = MIPC
Other name(s): SUR1 (gene name); CSH1 (gene name)
Systematic name: GDP-α-D-mannose:(4R)-4-hydroxy-N-[(2R)-2-hydroxy-very-long-chain-acyl]-1-O-[(1D-myo-inositol-1-O-yl)hydroxyphosphoryl]sphinganine mannosyltransferase (configuration-retaining)
Comments: The simplest complex sphingolipid of yeast, inositol-phospho-α-hydroxyphytoceramide (IPC), is usually mannosylated to yield mannosyl-inositol-phospho-α hydroxyphytoceramide (MIPC). The enzyme is located in the Golgi apparatus, and utilizes GDP-mannose as the mannosyl group donor. It consists of a catalytic subunit (SUR1 or CSH1) and a regulatory subunit (CSG2).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Beeler, T.J., Fu, D., Rivera, J., Monaghan, E., Gable, K. and Dunn, T.M. SUR1 (CSG1/BCL21), a gene necessary for growth of Saccharomyces cerevisiae in the presence of high Ca2+ concentrations at 37 degrees C, is required for mannosylation of inositolphosphorylceramide. Mol. Gen. Genet. 255 (1997) 570–579. [DOI] [PMID: 9323360]
2.  Dean, N., Zhang, Y.B. and Poster, J.B. The VRG4 gene is required for GDP-mannose transport into the lumen of the Golgi in the yeast, Saccharomyces cerevisiae. J. Biol. Chem. 272 (1997) 31908–31914. [DOI] [PMID: 9395539]
3.  Uemura, S., Kihara, A., Inokuchi, J. and Igarashi, Y. Csg1p and newly identified Csh1p function in mannosylinositol phosphorylceramide synthesis by interacting with Csg2p. J. Biol. Chem. 278 (2003) 45049–45055. [DOI] [PMID: 12954640]
[EC 2.4.1.370 created 2019]
 
 
EC 3.5.1.103     Relevance: 99%
Accepted name: N-acetyl-1-D-myo-inositol-2-amino-2-deoxy-α-D-glucopyranoside deacetylase
Reaction: 1-O-(2-acetamido-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol + H2O = 1-O-(2-amino-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol + acetate
For diagram of mycothiol biosynthesis, click here
Glossary: mycothiol = 1-O-[2-(N2-acetyl-L-cysteinamido)-2-deoxy-α-D-glucopyranosyl]-1D-myo-inositol
Other name(s): MshB
Systematic name: 1-(2-acetamido-2-deoxy-α-D-glucopyranosyl)-1D-myo-inositol acetylhydrolase
Comments: This enzyme is considered the key enzyme and rate limiting step in the mycothiol biosynthesis pathway [1]. In addition to acetylase activity, the enzyme possesses weak activity of EC 3.5.1.115, mycothiol S-conjugate amidase, and shares sequence similarity with that enzyme [2]. The enzyme requires a divalent transition metal ion for activity, believed to be Zn2+ [3].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Rawat, M., Kovacevic, S., Billman-Jacobe, H. and Av-Gay, Y. Inactivation of mshB, a key gene in the mycothiol biosynthesis pathway in Mycobacterium smegmatis. Microbiology 149 (2003) 1341–1349. [DOI] [PMID: 12724395]
2.  Newton, G.L., Av-Gay, Y. and Fahey, R.C. N-Acetyl-1-D-myo-inosityl-2-amino-2-deoxy-α-D-glucopyranoside deacetylase (MshB) is a key enzyme in mycothiol biosynthesis. J. Bacteriol. 182 (2000) 6958–6963. [DOI] [PMID: 11092856]
3.  Maynes, J.T., Garen, C., Cherney, M.M., Newton, G., Arad, D., Av-Gay, Y., Fahey, R.C. and James, M.N. The crystal structure of 1-D-myo-inosityl 2-acetamido-2-deoxy-α-D-glucopyranoside deacetylase (MshB) from Mycobacterium tuberculosis reveals a zinc hydrolase with a lactate dehydrogenase fold. J. Biol. Chem. 278 (2003) 47166–47170. [DOI] [PMID: 12958317]
[EC 3.5.1.103 created 2010]
 
 
EC 2.7.1.64     Relevance: 98.9%
Accepted name: inositol 3-kinase
Reaction: ATP + myo-inositol = ADP + 1D-myo-inositol 3-phosphate
Other name(s): inositol-1-kinase (phosphorylating); myoinositol kinase; myo-inositol 1-kinase
Systematic name: ATP:myo-inositol 1-phosphotransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37278-07-2
References:
1.  English, P.D., Dietz, M. and Albersheim, P. Myoinositol kinase: partial purification and identification of product. Science 151 (1966) 198–199. [DOI] [PMID: 5907906]
2.  Loewus, M.W., Sasaki, K., Leavitt, A.C., Muscell, L., Sherman, W.R. and Loewus, F.A. Enantiomeric form of myo-inositol-1-phosphate produced by myo-inositol-1-phosphate synthase and myoinositol kinase in higher-plants. Plant Physiol. 70 (1982) 1661–1663. [PMID: 16662739]
3.  Stephens, L.R., Kay, R.R. and Irvine, R.F. A myo-inositol D-3 hydroxykinase activity in Dictyostelium. Biochem. J. 272 (1990) 201–210. [PMID: 2176081]
[EC 2.7.1.64 created 1972, modified 2001]
 
 
EC 3.1.3.62     Relevance: 98.9%
Accepted name: multiple inositol-polyphosphate phosphatase
Reaction: (1) myo-inositol hexakisphosphate + H2O = 1D-myo-inositol 1,2,4,5,6-pentakisphosphate + phosphate
(2) 1D-myo-inositol 1,2,4,5,6-pentakisphosphate + H2O = 1D-myo-inositol 1,2,5,6-tetrakisphosphate + phosphate
(3) 1D-myo-inositol 1,2,5,6-tetrakisphosphate + H2O = 1D-myo-inositol 1,2,6-trisphosphate + phosphate
(4) 1D-myo-inositol 1,2,6-trisphosphate + H2O = 1D-myo-inositol 1,2-bisphosphate + phosphate
(5) 1D-myo-inositol 1,2-bisphosphate + H2O = 1D-myo-inositol 2-phosphate + phosphate
Glossary: myo-inositol hexakisphosphate = phytate
1D-myo-inositol 1,3,4,5,6-pentakisphosphate = Ins(1,3,4,5,6)P5
1D-myo-inositol 1,3,4,5-tetrakisphosphate = Ins(1,3,4,5)P4
1D-myo-inositol 1,4,5,6-tetrakisphosphate = Ins(1,4,5,6)P4
1D-myo-inositol 1,4,5-trisphosphate = Ins(1,4,5)P3
1D-myo-inositol 2,3-bisphosphate = Ins(2,3)P2
1D-myo-inositol 2-phosphate = Ins(2)P
Other name(s): MIPP; phytase (ambiguous); 1D-myo-inositol-hexakisphosphate 5-phosphohydrolase (incorrect)
Systematic name: myo-inositol-hexakisphosphate phosphohydrolase
Comments: This ubiquitous enzyme degrades myo-inositol hexakisphosphate (phytate) to Ins(2,3)P2 and Ins(2)P. Activities have been characterized in the yeast Saccharomyces cerevisiae [2], the plant Lupinus albus [3] and the bacteria Bacillus sp. [4] and Raoultella terrigena [5]. In mammal cells Ins(2,3)P2 and Ins(2)P are the major inositol phosphate compounds found [6]. The mammal enzyme is also active on Ins(1,3,4,5,6)P5 that is dephosphorylated to Ins(1,4,5,6)P4 and Ins(1,4,5)P3, and on 2,3-bisphospho-D-glycerate (cf. EC 3.1.3.80, 2,3-bisphosphoglycerate 3-phosphatase). In addition, it acts on Ins(1,3,4,5)P4 to yield Ins(1,4,5)P3 in vitro (cf. EC 3.1.3.67, phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase) [7]. It does not hydrolyse phosphates from the 2-positions of inositol phosphates [6]. In other organisms the degradation of phytate follows different routes. (cf. EC 3.1.3.8, 3-phytase, EC 3.1.3.26, 4-phytase, and EC 3.1.3.72, 5-phytase).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 116958-30-6
References:
1.  Craxton, A., Caffrey, J.J., Burkhart, W., Safrany, S.T. and Shears, S.B. Molecular cloning and expression of a rat hepatic multiple inositol polyphosphate phosphatase. Biochem. J. 328 (1997) 75–81. [DOI] [PMID: 9359836]
2.  Greiner, R., Alminger, M.L. and Carlsson, N.G. Stereospecificity of myo-inositol hexakisphosphate dephosphorylation by a phytate-degrading enzyme of baker’s yeast. J. Agric. Food Chem. 49 (2001) 2228–2233. [DOI] [PMID: 11368581]
3.  Greiner, R., Larsson Alminger, M., Carlsson, N.G., Muzquiz, M., Burbano, C., Cuadrado, C., Pedrosa, M.M. and Goyoaga, C. Pathway of dephosphorylation of myo-inositol hexakisphosphate by phytases of legume seeds. J. Agric. Food Chem. 50 (2002) 6865–6870. [DOI] [PMID: 12405789]
4.  Greiner, R., Farouk, A., Alminger, M.L. and Carlsson, N.G. The pathway of dephosphorylation of myo-inositol hexakisphosphate by phytate-degrading enzymes of different Bacillus spp. Can. J. Microbiol. 48 (2002) 986–994. [DOI] [PMID: 12556126]
5.  Greiner, R. and Carlsson, N.G. myo-Inositol phosphate isomers generated by the action of a phytate-degrading enzyme from Klebsiella terrigena on phytate. Can. J. Microbiol. 52 (2006) 759–768. [DOI] [PMID: 16917535]
6.  Nguyen Trung, M., Kieninger, S., Fandi, Z., Qiu, D., Liu, G., Mehendale, N.K., Saiardi, A., Jessen, H., Keller, B. and Fiedler, D. Stable isotopomers of myo-inositol uncover a complex MINPP1-dependent inositol phosphate network. ACS Cent. Sci. 8 (2022) 1683–1694. [DOI] [PMID: 36589890]
7.  Yu, J., Leibiger, B., Yang, S.N., Shears, S.B., Leibiger, I.B., Berggren, P.O. and Barker, C.J. Multiple inositol polyphosphate phosphatase compartmentalization separates inositol phosphate metabolism from inositol lipid signaling. Biomolecules 13 (2023) . [DOI] [PMID: 37371464]
[EC 3.1.3.62 created 1992, modified 2002, modified 2023]
 
 
EC 2.4.1.206     Relevance: 98.3%
Accepted name: lactosylceramide 1,3-N-acetyl-β-D-glucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of lactotetraosylceramide biosynthesis, click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
lactotriosylceramide = N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): LA2 synthase; β1→3-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-lactosylceramide β-acetylglucosaminyltransferase; lactosylceramide β-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:D-galactosyl-1,4-β-D-glucosylceramide β-1,3-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide 3-β-N-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-N-acetylglucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-N-acetylglucosaminyltransferase (configuration-inverting)
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 83682-80-8
References:
1.  Gottfries, J., Percy, A.K., Maansson, J.-E., Fredman, P., Wilkstrand, C.J., Friedman, H.S., Bigner, D.D. and Svennerholm, L. Glycolipids and glycosyltransferases in permanent cell lines established from human medulloblastomas. Biochim. Biophys. Acta 1081 (1991) 253–261. [DOI] [PMID: 1825612]
2.  Holmes, E.H., Hakomori, S. and Ostrander, G.K. Synthesis of type 1 and 2 lacto series glycolipid antigens in human colonic adenocarcinoma and derived cell lines is due to activation of a normally unexpressed β1→3N-acetylglucosaminyltransferase. J. Biol. Chem. 262 (1987) 15649–15658. [PMID: 2960671]
3.  Percy, A.K., Gottfries, J., Vilbergsson, G., Maansson, J.E. and Svennerholm, J. Glycosphingolipid glycosyltransferases in human fetal brain. J. Neurochem. 56 (1991) 1461–1465. [DOI] [PMID: 1901591]
[EC 2.4.1.206 created 1992]
 
 
EC 5.5.1.4     Relevance: 98.2%
Accepted name: inositol-3-phosphate synthase
Reaction: D-glucose 6-phosphate = 1D-myo-inositol 3-phosphate
For diagram of myo-inositol biosynthesis, click here and for mechanism of reaction, click here
Other name(s): myo-inositol-1-phosphate synthase; D-glucose 6-phosphate cycloaldolase; inositol 1-phosphate synthatase; glucose 6-phosphate cyclase; inositol 1-phosphate synthetase; glucose-6-phosphate inositol monophosphate cycloaldolase; glucocycloaldolase; 1L-myo-inositol-1-phosphate lyase (isomerizing)
Systematic name: 1D-myo-inositol-3-phosphate lyase (isomerizing)
Comments: Requires NAD+, which dehydrogenates the -CHOH- group to -CO- at C-5 of the glucose 6-phosphate, making C-6 into an active methylene, able to condense with the -CHO at C-1. Finally, the enzyme-bound NADH reconverts C-5 into the -CHOH- form.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9032-95-5
References:
1.  Eisenberg, F., Jr. D-Myoinositol 1-phosphate as product of cyclization of glucose 6-phosphate and substrate for a specific phosphatase in rat testis. J. Biol. Chem. 242 (1967) 1375–1382. [PMID: 4290245]
2.  Sherman, W.R., Stewart, M.A. and Zinbo, M. Mass spectrometric study on the mechanism of D-glucose 6-phosphate-L-myo-inositol 1-phosphate cyclase. J. Biol. Chem. 244 (1969) 5703–5708. [PMID: 4310603]
3.  Barnett, J.E.G. and Corina, D.L. The mechanism of glucose 6-phosphate-D-myo-inositol 1-phosphate cyclase of rat testis. The involvement of hydrogen atoms. Biochem. J. 108 (1968) 125–129. [PMID: 4297937]
4.  Barnett, J.E.G., Rasheed, A. and Corina, D.L. Partial reactions of glucose 6-phosphate-1L-myo-inositol 1-phosphate cyclase. Biochem. J. 131 (1973) 21–30. [PMID: 4352864]
[EC 5.5.1.4 created 1972, modified 2001]
 
 
EC 2.1.1.39     Relevance: 98.2%
Accepted name: inositol 3-methyltransferase
Reaction: S-adenosyl-L-methionine + myo-inositol = S-adenosyl-L-homocysteine + 1D-3-O-methyl-myo-inositol
For diagram of the biosynthesis of methyl-myo-inositols, click here
Other name(s): inositol L-1-methyltransferase; myo-inositol 1-methyltransferase; S-adenosylmethionine:myo-inositol 1-methyltransferase; myo-inositol 1-O-methyltransferase (name based on 1L-numbering system and not 1D-numbering); S-adenosyl-L-methionine:myo-inositol 1-O-methyltransferase
Systematic name: S-adenosyl-L-methionine:1D-myo-inositol 3-O-methyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37257-05-9
References:
1.  Hofmann, H., Wagner, I. and Hoffmann-Ostenhof, O. Untersuchungen über die Biosynthese der Cyclite. XXIV. Über ein lösliches Enzym aus Vinca rosea, das myo-Inosit zu L-Bornesit methyliert. Hoppe-Seyler's Z. Physiol. Chem. 350 (1969) 1465–1468. [PMID: 5362621]
[EC 2.1.1.39 created 1972, modified 2002]
 
 
EC 2.1.1.40     Relevance: 98.2%
Accepted name: inositol 1-methyltransferase
Reaction: S-adenosyl-L-methionine + myo-inositol = S-adenosyl-L-homocysteine + 1D-1-O-methyl-myo-inositol
For diagram of the biosynthesis of methyl-myo-inositols, click here
Other name(s): inositol D-1-methyltransferase; S-adenosylmethionine:myo-inositol 3-methyltransferase; myo-inositol 3-O-methyltransferase; inositol 3-O-methyltransferase (name based on 1L-numbering system and not 1D-numbering); S-adenosyl-L-methionine:myo-inositol 3-O-methyltransferase
Systematic name: S-adenosyl-L-methionine:1D-myo-inositol 1-O-methyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37257-06-0
References:
1.  Wagner, I., Hofmann, H. and Hoffmann-Ostenhof, O. Untersuchungen über die Biosynthese der Cyclite. XXIII. Über ein lösliches Enzym aus Erbsenkeimlingen, das myo-Inosit zu D-Bornesit methyliert. Hoppe-Seyler's Z. Physiol. Chem. 350 (1969) 1460–1464. [PMID: 5362620]
[EC 2.1.1.40 created 1972, modified 2002]
 
 
EC 2.4.1.102     Relevance: 98.2%
Accepted name: β-1,3-galactosyl-O-glycosyl-glycoprotein β-1,6-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + O3-[β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl]-L-seryl/threonyl-[protein] = UDP + O3-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Glossary: core 1 = O3-[β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl]-L-seryl/threonyl-[protein]
core 2 = O3-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Other name(s): O-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase I; β6-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-mucin β-(1→6)-acetylglucosaminyltransferase; core 2 acetylglucosaminyltransferase; core 6-β-GlcNAc-transferase A; UDP-N-acetyl-D-glucosamine:O-glycosyl-glycoprotein (N-acetyl-D-glucosamine to N-acetyl-D-galactosamine of β-D-galactosyl-1,3-N-acetyl-D-galactosaminyl-R) β-1,6-N-acetyl-D-glucosaminyltransferase; GCNT1; GCNT3; UDP-N-acetyl-D-glucosamine:O-glycosyl-glycoprotein (N-acetyl-D-glucosamine to N-acetyl-D-galactosamine of β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl-R) 6-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:O3-[β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl]-glycoprotein 6-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: The enzyme catalyses the addition of N-acetyl-α-D-glucosamine to the core 1 structure of O-glycans forming core 2.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 95978-15-7
References:
1.  Brockhausen, I., Rachaman, E.S., Matta, K.L. and Schachter, H. The separation by liquid chromatography (under elevated pressure) of phenyl, benzyl, and O-nitrophenyl glycosides of oligosaccharides. Analysis of substrates and products for four N-acetyl-D-glucosaminyl-transferases involved in mucin synthesis. Carbohydr. Res. 120 (1983) 3–16. [DOI] [PMID: 6226356]
2.  Williams, D., Longmore, G., Matta, K.L. and Schachter, H. Mucin synthesis. II. Substrate specificity and product identification studies on canine submaxillary gland UDP-GlcNAc:Gal β1-3GalNAc(GlcNAc→GalNAc) β6-N-acetylglucosaminyltransferase. J. Biol. Chem. 255 (1980) 11253–11261. [PMID: 6449508]
3.  Williams, D. and Schachter, H. Mucin synthesis. I. Detection in canine submaxillary glands of an N-acetylglucosaminyltransferase which acts on mucin substrates. J. Biol. Chem. 255 (1980) 11247–11252. [PMID: 6449507]
[EC 2.4.1.102 created 1983, modified 2018]
 
 
EC 2.4.1.62     Relevance: 97.6%
Accepted name: ganglioside galactosyltransferase
Reaction: UDP-α-D-galactose + an N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + a β-D-galactosyl-(1→3)-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
Glossary: N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = ganglioside GM2
a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GM1a
Other name(s): UDP-galactose—ceramide galactosyltransferase; uridine diphosphogalactose-ceramide galactosyltransferase; UDP galactose-LAC Tet-ceramide α-galactosyltransferase; UDP-galactose-GM2 galactosyltransferase; uridine diphosphogalactose-GM2 galactosyltransferase; uridine diphosphate D-galactose:glycolipid galactosyltransferase; UDP-galactose:N-acetylgalactosaminyl-(N-acetylneuraminyl) galactosyl-glucosyl-ceramide galactosyltransferase; UDP-galactose-GM2 ganglioside galactosyltransferase; GM1-synthase; UDP-galactose:N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosyl-N-acylsphingosine β-1,3-D-galactosyltransferase; UDP-galactose:N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-(1→4)-β-D-glucosyl-N-acylsphingosine 3-β-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-D-galactosyltransferase
Comments: The substrate is also known as gangloside GM2, the product as gangloside GM1a
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37217-28-0
References:
1.  Basu, S., Kaufman, B. and Roseman, S. Conversion of Tay-Sachs ganglioside to monosialoganglioside by brain uridine diphosphate D-galactose: glycolipid galactosyltransferase. J. Biol. Chem. 240 (1965) 4115–4117. [PMID: 5842076]
2.  Yip, G.B. and Dain, J.A. The enzymic synthesis of ganglioside. II. UDP-galactose: N-acetylgalactosaminyl-(N-acetylneuraminyl)galactosyl-glucosyl-ceramide galactosyltransferase in rat brain. Biochim. Biophys. Acta 206 (1970) 252–260. [DOI] [PMID: 4987145]
3.  Yip, M.C.M. and Dain, J.A. Frog brain uridine diphosphate galactose-N-acetylgalactosaminyl-N-acetylneuraminylgalactosylglucosylceramide galactosyltransferase. Biochem. J. 118 (1970) 247–252. [PMID: 5484669]
[EC 2.4.1.62 created 1972, modified 2013]
 
 
EC 2.4.1.146     Relevance: 97.6%
Accepted name: β-1,3-galactosyl-O-glycosyl-glycoprotein β-1,3-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + 3-O-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein] = UDP + 3-O-{N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Glossary: core 2 = 3-O-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Other name(s): O-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase II; uridine diphosphoacetylglucosamine-mucin β(1→3)-acetylglucosaminyltransferase (elongating); elongation 3β-GalNAc-transferase; UDP-N-acetyl-D-glucosamine:O-glycosyl-glycoprotein (N-acetyl-D-glucosamine to β-D-galactose of β-D-galactosyl-1,3-(N-acetyl-D-glucosaminyl-1,6)-N-acetyl-D-galactosaminyl-R) β-1,3-N-acetyl-D-glucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→3)-[N-acetyl-D-glucosaminyl-(1→6)]-N-acetyl-D-galactosaminyl-R 3-β-N-acetyl-D-glucosaminyltransferase; B3GNT3 (gene name)
Systematic name: UDP-N-acetyl-α-D-glucosamine:3-O-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein] 3-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: The enzyme catalyses the addition of N-acetyl-α-D-glucosamine to the core 2 structure of O-glycans.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 87927-99-9
References:
1.  Brockhausen, I., Rachaman, E.S., Matta, K.L. and Schachter, H. The separation by liquid chromatography (under elevated pressure) of phenyl, benzyl, and O-nitrophenyl glycosides of oligosaccharides. Analysis of substrates and products for four N-acetyl-D-glucosaminyl-transferases involved in mucin synthesis. Carbohydr. Res. 120 (1983) 3–16. [DOI] [PMID: 6226356]
2.  Shiraishi, N., Natsume, A., Togayachi, A., Endo, T., Akashima, T., Yamada, Y., Imai, N., Nakagawa, S., Koizumi, S., Sekine, S., Narimatsu, H. and Sasaki, K. Identification and characterization of three novel β 1,3-N-acetylglucosaminyltransferases structurally related to the β 1,3-galactosyltransferase family. J. Biol. Chem. 276 (2001) 3498–3507. [PMID: 11042166]
[EC 2.4.1.146 created 1984, modified 2018]
 
 
EC 1.13.99.1     Relevance: 97.6%
Accepted name: inositol oxygenase
Reaction: myo-inositol + O2 = D-glucuronate + H2O
For diagram of mammalian ascorbic-acid biosynthesis, click here
Other name(s): meso-inositol oxygenase; myo-inositol oxygenase; MOO
Systematic name: myo-inositol:oxygen oxidoreductase
Comments: An iron protein.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9029-59-8
References:
1.  Charalampous, F.C. Biochemical studies on inositol. V. Purification and properties of the enzyme that cleaves inositol to D-glucuronic acid. J. Biol. Chem. 234 (1959) 220–227. [PMID: 13630882]
2.  Reddy, C.C., Swan, J.S. and Hamilton, G.A. myo-Inositol oxygenase from hog kidney. I. Purification and characterization of the oxygenase and of an enzyme complex containing the oxygenase and D-glucuronate reductase. J. Biol. Chem. 256 (1981) 8510–8518. [PMID: 7263666]
3.  Arner, R.J., Prabhu, K.S., Thompson, J.T., Hildenbrandt, G.R., Liken, A.D. and Reddy, C.C. myo-Inositol oxygenase: molecular cloning and expression of a unique enzyme that oxidizes myo-inositol and D-chiro-inositol. Biochem. J. 360 (2001) 313–320. [PMID: 11716759]
[EC 1.13.99.1 created 1961 as EC 1.99.2.6, transferred 1965 to EC 1.13.1.11, transferred 1972 to EC 1.13.99.1, modified 2002]
 
 
EC 2.4.1.163      
Transferred entry: β-galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide β-1,3-acetylglucosaminyltransferase, now included in EC 2.4.1.149, N-acetyllactosaminide β-1,3-N-acetylglucosaminyltransferase
[EC 2.4.1.163 created 1989, deleted 2016]
 
 
EC 2.4.1.164      
Transferred entry: galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide β-1,6-N-acetylglucosaminyltransferase, now included with EC 2.4.1.150, N-acetyllactosaminide β-1,6-N-acetylglucosaminyltransferase
[EC 2.4.1.164 created 1989, deleted 2016]
 
 
EC 2.4.1.149     Relevance: 97.2%
Accepted name: N-acetyllactosaminide β-1,3-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R = UDP + N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R
Other name(s): uridine diphosphoacetylglucosamine-acetyllactosaminide β1→3-acetylglucosaminyltransferase; poly-N-acetyllactosamine extension enzyme; Galβ1→4GlcNAc-R β1→3 N-acetylglucosaminyltransferase; UDP-GlcNAc:GalR β-D-3-N-acetylglucosaminyltransferase; N-acetyllactosamine β(1-3)N-acetylglucosaminyltransferase; UDP-GlcNAc:Galβ1→4GlcNAcβ-Rβ1→3-N-acetylglucosaminyltransferase; GnTE; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-1,4-N-acetyl-D-glucosamine β-1,3-acetyl-D-glucosaminyltransferase; β-galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide β-1,3-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→4)-N-acetyl-D-glucosamine 3-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R 3-β N-acetylglucosaminyltransferase (configuration-inverting)
Comments: Acts on β-galactosyl-1,4-N-acetylglucosaminyl termini on glycoproteins, glycolipids, and oligosaccharides.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 85638-39-7
References:
1.  Van den Eijnden, D.H., Winterwerp, H., Smeeman, P. and Schiphorst, W.E.C.M. Novikoff ascites tumor cells contain N-acetyllactosaminide β1→3 and β1→6 N-acetylglucosaminyltransferase activity. J. Biol. Chem. 258 (1983) 3435–3437. [PMID: 6219989]
2.  Basu, M. and Basu, S. Biosynthesis in vitro of Ii core glycosphingolipids from neolactotetraosylceramide by β 1-3- and β 1-6-N-acetylglucosaminyltransferases from mouse T-lymphoma. J. Biol. Chem. 259 (1984) 12557–12562. [PMID: 6238026]
3.  Takeya, A., Hosomi, O. and Kogure, T. The presence of N-acetyllactosamine and lactose: β (1-3)N-acetylglucosaminyltransferase activity in human urine. Jpn. J. Med. Sci. Biol. 38 (1985) 1–8. [PMID: 3160874]
[EC 2.4.1.149 created 1984 (EC 2.4.1.163 created 1989, incorporated 2016), modified 2016]
 
 
EC 2.4.99.11      
Deleted entry: lactosylceramide α-2,6-N-sialyltransferase. Now included with EC 2.4.3.1, β-galactoside α-(2,6)-sialyltransferase
[EC 2.4.99.11 created 1992, deleted 2017]
 
 
EC 3.1.3.67     Relevance: 96.5%
Accepted name: phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase
Reaction: 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate + H2O = 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate + phosphate
For diagram of 1-phosphatidyl-myo-inositol metabolism, click here
Glossary: inositol 1,4,5-trisphosphate = Ins(1,4,5)P3
inositol 1,3,4,5-tetrakisphosphate = Ins(1,3,4,5)P4
1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate = PtdIns(4,5)P2
1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate = PtdIns(3,4,5)P3
Other name(s): PTEN (gene name); MMAC1 (gene name); phosphatidylinositol-3,4,5-trisphosphate 3-phosphohydrolase
Systematic name: 1-phosphatidyl-1D-myo-inositol-3,4,5-trisphosphate 3-phosphohydrolase
Comments: Requires Mg2+. Does not dephosphorylate inositol 4,5-bisphosphate. This enzyme still works when the 2,3-bis(acyloxy)propyl group is removed, i.e., it hydrolyses Ins(1,3,4,5)P4 to Ins(1,4,5)P3
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 210488-47-4
References:
1.  Kabuyama, Y., Nakatsu, N., Homma, Y., Fukui, Y. Purification and characterization of phosphatidyl inositol-3,4,5-trisphosphate phosphatase in bovine thymus. Eur. J. Biochem. 238 (1996) 350–356. [DOI] [PMID: 8681945]
2.  Maehama, T. and Dixon, J.E. The tumor suppressor, PTEN /MMAC1, dephosphorylates the lipid second messenger, phosphatidylinositol 3,4,5-trisphosphate. J. Biol. Chem. 273 (1998) 13375–13378. [DOI] [PMID: 9593664]
[EC 3.1.3.67 created 1999, modified 2002]
 
 
EC 1.1.1.18     Relevance: 96%
Accepted name: inositol 2-dehydrogenase
Reaction: myo-inositol + NAD+ = 2,4,6/3,5-pentahydroxycyclohexanone + NADH + H+
Other name(s): myo-inositol 2-dehydrogenase; myo-inositol:NAD+ oxidoreductase; inositol dehydrogenase; myo-inositol dehydrogenase
Systematic name: myo-inositol:NAD+ 2-oxidoreductase
Links to other databases: BRENDA, EXPASY, GTD, KEGG, MetaCyc, PDB, CAS registry number: 9028-25-5
References:
1.  Berman, T. and Magasanik, B. The pathway of myo-inositol degradation in Aerobacter aerogenes. Dehydrogenation and dehydration. J. Biol. Chem. 241 (1966) 800–806. [PMID: 5905122]
2.  Larner, J., Jackson, W.T., Graves, D.J. and Stamner, J.R. Inositol dehydrogenase from Aerobacter aerogenes. Arch. Biochem. Biophys. 60 (1956) 352–363. [DOI] [PMID: 13292912]
3.  Vidal-Lieria, M. and van Uden, N. Inositol dehydrogenase from the yeast Cryptococcus melibiosum. Biochim. Biophys. Acta 293 (1973) 295–303. [DOI] [PMID: 4351258]
[EC 1.1.1.18 created 1961]
 
 
EC 3.1.4.43     Relevance: 96%
Accepted name: glycerophosphoinositol inositolphosphodiesterase
Reaction: 1-(sn-glycero-3-phospho)-1D-myo-inositol + H2O = glycerol + 1D-myo-inositol 1-phosphate
For diagram of 1-(glycero-3-phospho)-myo-inositol catabolism, click here
Other name(s): 1,2-cyclic-inositol-phosphate phosphodiesterase; D-myo-inositol 1:2-cyclic phosphate 2-phosphohydrolase; D-inositol 1,2-cyclic phosphate 2-phosphohydrolase; D-myo-inositol 1,2-cyclic phosphate 2-phosphohydrolase; 1-D-myo-inositol-1,2-cyclic-phosphate 2-inositolphosphohydrolase; inositol-1,2-cyclic-phosphate 2-inositolphosphohydrolase
Systematic name: 1-(sn-glycero-3-phospho)-1D-myo-inositol inositolphosphohydrolase
Comments: This enzyme also hydrolyses Ins(cyclic1,2)P to Ins-1-P
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9076-91-9 (from EC 3.1.4.36), 72414-13-2 (not distinguished from EC 3.1.4.44)
References:
1.  Dawson, R.M.C. and Hemington, N. A phosphodiesterase in rat kidney cortex that hydrolyses glycerylphosphorylinositol. Biochem. J. 162 (1977) 241–245. [PMID: 192216]
2.  Dawson, R.M.C. and Clarke, N.G. D-myoInositol 1:2-cyclic phosphate 2-phosphohydrolase. Biochem. J. 127 (1972) 113–118. [PMID: 4342209]
3.  Dawson, R.M.C. and Clarke, N.G. A comparison of D-inositol 1:2-cyclic phosphate 2-phosphohydrolase with other phosphodiesterases of kidney. Biochem. J. 134 (1973) 59–67. [PMID: 4353088]
4.  Ross, T.S. and Majerus, P.W. Inositol-1,2-cyclic-phosphate 2-inositolphosphohydrolase. Substrate specificity and regulation of activity by phospholipids, metal ion chelators, and inositol 2-phosphate. J. Biol. Chem. 266 (1991) 851–856. [PMID: 1845995]
[EC 3.1.4.43 created 1984, (EC 3.1.4.36 created 1976, incorporated 2002), modified 2002]
 
 
EC 2.4.3.4     Relevance: 95.8%
Accepted name: β-galactoside α-2,3-sialyltransferase
Reaction: CMP-N-acetylneuraminate + β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-R = CMP + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-R
Other name(s): CMP-N-acetylneuraminate:β-D-galactoside α-2,3-N-acetylneuraminyl-transferase
Systematic name: CMP-N-acetylneuraminate:β-D-galactoside α-(2→3)-N-acetylneuraminyl-transferase
Comments: The acceptor is Galβ1,3GalNAc-R, where R is H, a threonine or serine residue in a glycoprotein, or a glycolipid. Lactose can also act as acceptor. May be identical with EC 2.4.3.2 β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 71124-51-1
References:
1.  Rearick, J.I., Sadler, J.E., Paulson, J.C. and Hill, R.L. Enzymatic characterization of β D-galactoside α2→3 sialyltransferase from porcine submaxillary gland. J. Biol. Chem. 254 (1979) 4444–4451. [PMID: 438198]
2.  Sadler, J.E., Rearick, J.I., Paulson, J.C. and Hill, R.L. Purification to homogeneity of a β-galactoside α2→3 sialyltransferase and partial purification of an α-N-acetylgalactosaminide α2→6 sialyltransferase from porcine submaxillary glands. J. Biol. Chem. 254 (1979) 4434–4442. [PMID: 438196]
[EC 2.4.3.4 created 1984 as EC 2.4.99.4, modified 1986, transferred 2022 to EC 2.4.3.4]
 
 
EC 3.1.3.36     Relevance: 95.1%
Accepted name: phosphoinositide 5-phosphatase
Reaction: 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate + H2O = 1-phosphatidyl-1D-myo-inositol 4-phosphate + phosphate
For diagram of 1-phosphatidyl-myo-inositol metabolism, click here
Glossary: 1-phosphatidyl-1D-myo-inositol 4-phosphate = PtdIns4P
1-phosphatidyl-1D-myo-inositol 1,4-bisphosphate = PtdIns(1,4)P2
1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate = PtdIns(4,5)P2
1-phosphatidyl-1D-myo-inositol 1,3,4-trisphosphate = PtdIns(1,3,4)P3
1-phosphatidyl-1D-myo-inositol 1,4,5-trisphosphate = PtdIns(1,4,5)P3
1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate = PtdIns(3,4,5)P3
1-phosphatidyl-1D-myo-inositol 1,3,4,5-tetrakisphosphate = PtdIns(1,3,4,5)P4
Other name(s): type II inositol polyphosphate 5-phosphatase; triphosphoinositide phosphatase; IP3 phosphatase; PtdIns(4,5)P2 phosphatase; triphosphoinositide phosphomonoesterase; diphosphoinositide phosphatase; inositol 1,4,5-triphosphate 5-phosphomonoesterase; inositol triphosphate 5-phosphomonoesterase; phosphatidylinositol-bisphosphatase; phosphatidyl-myo-inositol-4,5-bisphosphate phosphatase; phosphatidylinositol 4,5-bisphosphate phosphatase; polyphosphoinositol lipid 5-phosphatase; phosphatidyl-inositol-bisphosphate phosphatase
Systematic name: phosphatidyl-myo-inositol-4,5-bisphosphate 4-phosphohydrolase
Comments: These enzymes can also remove the 5-phosphate from Ins(1,4,5)P3 and/or Ins(1,3,4,5)P4. They are a diverse family of enzymes, with differing abilities to catalyse two or more of the four reactions listed. They are thought to use inositol lipids rather than inositol phosphates as substrates in vivo. All of them can use either or both of PtdIns(4,5)P2 and PtdIns(3,4,5)P3 as substrates; this is the main property that distinguishes them from EC 3.1.3.56, inositol-polyphosphate 5-phosphatase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9036-01-5
References:
1.  Dawson, R.M.C. and Thompson, W. The triphosphoinositide phosphomonoesterase of brain tissue. Biochem. J. 91 (1964) 244–250. [PMID: 4284485]
2.  Roach, P.D. and Palmer, F.B.S. Human erythrocyte cytosol phosphatidyl-inositol-bisphosphate phosphatase. Biochim. Biophys. Acta 661 (1981) 323–333. [DOI] [PMID: 6271223]
3.  Woscholski, R. and Parker, P.J. Inositol phosphatases: constructive destruction of phosphoinositides and inositol phosphates. In: Cockcroft, S. (Ed.), Biology of Phosphoinositides, Biology of Phosphoinositides, Oxford, 2000, pp. 320–338.
[EC 3.1.3.36 created 1972, modified 2002]
 
 
EC 1.1.1.370     Relevance: 95.1%
Accepted name: scyllo-inositol 2-dehydrogenase (NAD+)
Reaction: scyllo-inositol + NAD+ = 2,4,6/3,5-pentahydroxycyclohexanone + NADH + H+
For diagram of inositol catabolism, click here
Glossary: 2,4,6/3,5-pentahydroxycyclohexanone = (2R,3S,4s,5R,6S)-2,3,4,5,6-pentahydroxycyclohexanone = scyllo-inosose
Other name(s): iolX (gene name)
Systematic name: scyllo-inositol:NAD+ 2-oxidoreductase
Comments: The enzyme, found in the bacterium Bacillus subtilis, has no activity with NADP+ [cf. EC 1.1.1.371, scyllo-inositol 2-dehydrogenase (NADP+)]. It is part of a scyllo-inositol degradation pathway leading to acetyl-CoA.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Morinaga, T., Ashida, H. and Yoshida, K. Identification of two scyllo-inositol dehydrogenases in Bacillus subtilis. Microbiology 156 (2010) 1538–1546. [DOI] [PMID: 20133360]
[EC 1.1.1.370 created 2014]
 
 
EC 2.4.1.184     Relevance: 95.1%
Accepted name: galactolipid galactosyltransferase
Reaction: 2 a 1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol = a 1,2-diacyl-3-O-[β-D-galactosyl-(1→6)-β-D-galactosyl]-sn-glycerol + a 1,2-diacyl-sn-glycerol
For diagram of galactosyl diacylglycerol, click here
Glossary: a 1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol = monogalactosyldiacylglycerol
Other name(s): galactolipid-galactolipid galactosyltransferase; galactolipid:galactolipid galactosyltransferase; interlipid galactosyltransferase; GGGT; DGDG synthase (ambiguous); digalactosyldiacylglycerol synthase (ambiguous); 3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol:mono-3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol β-D-galactosyltransferase; 3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol:3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol β-D-galactosyltransferase; SFR2 (gene name)
Systematic name: 1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol:1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol β-D-galactosyltransferase
Comments: The enzyme converts monogalactosyldiacylglycerol to digalactosyldiacylglycerol, trigalactosyldiacylglycerol and tetragalactosyldiacylglycerol. All residues are connected by β linkages. The activity is localized to chloroplast envelope membranes, but it does not contribute to net galactolipid synthesis in plants, which is performed by EC 2.4.1.46, monogalactosyldiacylglycerol synthase, and EC 2.4.1.241, digalactosyldiacylglycerol synthase. Note that the β,β-digalactosyldiacylglycerol formed by this enzyme is different from the more common α,β-digalactosyldiacylglycerol formed by EC 2.4.1.241. The enzyme provides an important mechanism for the stabilization of the chloroplast membranes during freezing and drought stress.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 66676-74-2
References:
1.  Dorne, A.-J., Block, M.A., Joyard, J. and Douce, R. The galactolipid-galactolipid galactosyltransferase is located on the outer surface of the outer-membrane of the chloroplast envelope. FEBS Lett. 145 (1982) 30–34.
2.  Heemskerk, J.W.M., Wintermans, J.F.G.M., Joyard, J., Block, M.A., Dorne, A.-J. and Douce, R. Localization of galactolipid:galactolipid galactosyltransferase and acyltransferase in outer envelope membrane of spinach chloroplasts. Biochim. Biophys. Acta 877 (1986) 281–289.
3.  Heemskerk, J.W.M., Jacobs, F.H.H. and Wintermans, J.F.G.M. UDPgalactose-independent synthesis of monogalactosyldiacylglycerol. An enzymatic activity of the spinach chloroplast envelope. Biochim. Biophys. Acta 961 (1988) 38–47. [DOI]
4.  Kelly, A.A., Froehlich, J.E. and Dörmann, P. Disruption of the two digalactosyldiacylglycerol synthase genes DGD1 and DGD2 in Arabidopsis reveals the existence of an additional enzyme of galactolipid synthesis. Plant Cell 15 (2003) 2694–2706. [DOI] [PMID: 14600212]
5.  Benning, C. and Ohta, H. Three enzyme systems for galactoglycerolipid biosynthesis are coordinately regulated in plants. J. Biol. Chem. 280 (2005) 2397–2400. [DOI] [PMID: 15590685]
6.  Fourrier, N., Bedard, J., Lopez-Juez, E., Barbrook, A., Bowyer, J., Jarvis, P., Warren, G. and Thorlby, G. A role for SENSITIVE TO FREEZING2 in protecting chloroplasts against freeze-induced damage in Arabidopsis. Plant J. 55 (2008) 734–745. [DOI] [PMID: 18466306]
7.  Moellering, E.R., Muthan, B. and Benning, C. Freezing tolerance in plants requires lipid remodeling at the outer chloroplast membrane. Science 330 (2010) 226–228. [DOI] [PMID: 20798281]
[EC 2.4.1.184 created 1990, modified 2005, modified 2015]
 
 
EC 2.4.1.66     Relevance: 94.9%
Accepted name: procollagen glucosyltransferase
Reaction: UDP-α-D-glucose + [procollagen]-(5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine = UDP + [procollagen]-(5R)-5-O-[α-D-glucosyl-(1→2)-β-D-galactosyl]-5-hydroxy-L-lysine
Other name(s): galactosylhydroxylysine glucosyltransferase; collagen glucosyltransferase; collagen hydroxylysyl glucosyltransferase; galactosylhydroxylysyl glucosyltransferase; UDP-glucose-collagenglucosyltransferase; uridine diphosphoglucose-collagen glucosyltransferase; UDP-glucose:5-(D-galactosyloxy)-L-lysine-procollagen D-glucosyltransferase; UDP-glucose:(2S,5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine-[procollagen] D-glucosyltransferase
Systematic name: UDP-α-D-glucose:[procollagen]-(5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine 2-α-D-glucosyltransferase (configuration-retaining)
Comments: Involved in the synthesis of carbohydrate units in the complement system (cf. EC 2.4.1.50 procollagen galactosyltransferase).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9028-08-4
References:
1.  Bosmann, H.B. and Eylar, E.H. Attachment of carbohydrate to collagen. Isolation, purification and properties of the glucosyl transferase. Biochem. Biophys. Res. Commun. 30 (1968) 89–94. [DOI] [PMID: 5637038]
2.  Bosmann, H.B. and Eylar, E.H. Collagen-glucosyl transferase in fibriblasts transformed by oncogenic viruses. Nature 218 (1968) 582–583. [PMID: 4968368]
3.  Butler, W.T. and Cunningham, L.W. Evidence for the linkage of a disaccharide to hydroxylysine in tropocollagen. J. Biol. Chem. 241 (1966) 3882–3888. [PMID: 4288358]
4.  Kivirikko, K.I. and Myllyla, R. In: Hall, D.A. and Jackson, D.S. (Ed.), International Review of Connective Tissue Research, vol. 8, Academic Press, New York, 1979, p. 23.
5.  Sricholpech, M., Perdivara, I., Nagaoka, H., Yokoyama, M., Tomer, K.B. and Yamauchi, M. Lysyl hydroxylase 3 glucosylates galactosylhydroxylysine residues in type I collagen in osteoblast culture. J. Biol. Chem. 286 (2011) 8846–8856. [DOI] [PMID: 21220425]
[EC 2.4.1.66 created 1972]
 
 
EC 2.7.4.21     Relevance: 94.7%
Accepted name: inositol-hexakisphosphate 5-kinase
Reaction: (1) ATP + 1D-myo-inositol hexakisphosphate = ADP + 1D-myo-inositol 5-diphosphate 1,2,3,4,6-pentakisphosphate
(2) ATP + 1D-myo-inositol 1-diphosphate 2,3,4,5,6-pentakisphosphate = ADP + 1D-myo-inositol 1,5-bis(diphosphate) 2,3,4,6-tetrakisphosphate
Other name(s): ATP:1D-myo-inositol-hexakisphosphate phosphotransferase; IP6K; inositol-hexakisphosphate kinase (ambiguous)
Systematic name: ATP:1D-myo-inositol-hexakisphosphate 5-phosphotransferase
Comments: Three mammalian isoforms are known to exist.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 176898-37-6
References:
1.  Saiardi, A., Erdjument-Bromage, H., Snowman, A.M., Tempst, P. and Snyder, S.H. Synthesis of diphosphoinositol pentakisphosphate by a newly identified family of higher inositol polyphosphate kinases. Curr. Biol. 9 (1999) 1323–1326. [DOI] [PMID: 10574768]
2.  Schell, M.J., Letcher, A.J., Brearley, C.A., Biber, J., Murer, H. and Irvine, R.F. PiUS (Pi uptake stimulator) is an inositol hexakisphosphate kinase. FEBS Lett. 461 (1999) 169–172. [DOI] [PMID: 10567691]
3.  Albert, C., Safrany, S.T., Bembenek, M.E., Reddy, K.M., Reddy, K.K., Falck, J.-R., Bröcker, M., Shears, S.B. and Mayr, G.W. Biological variability in the structures of diphosphoinositol polyphosphates in Dictyostelium discoideum and mammalian cells. Biochem. J. 327 (1997) 553–560. [DOI] [PMID: 9359429]
4.  Lin, H., Fridy, P.C., Ribeiro, A.A., Choi, J.H., Barma, D.K., Vogel, G., Falck, J.R., Shears, S.B., York, J.D. and Mayr, G.W. Structural analysis and detection of biological inositol pyrophosphates reveal that the family of VIP/diphosphoinositol pentakisphosphate kinases are 1/3-kinases. J. Biol. Chem. 284 (2009) 1863–1872. [DOI] [PMID: 18981179]
5.  Wang, H., Falck, J.R., Hall, T.M. and Shears, S.B. Structural basis for an inositol pyrophosphate kinase surmounting phosphate crowding. Nat. Chem. Biol. 8 (2012) 111–116. [DOI] [PMID: 22119861]
[EC 2.7.4.21 created 2002 as EC 2.7.1.152, transferred 2003 to EC 2.7.4.21, modified 2013, modified 2022]
 
 
EC 2.7.1.153     Relevance: 94.5%
Accepted name: phosphatidylinositol-4,5-bisphosphate 3-kinase
Reaction: ATP + 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate = ADP + 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate
For diagram of 1-phosphatidyl-myo-inositol metabolism (part 2), click here
Glossary: 1-phosphatidyl-1D-myo-inositol = PtdIns
1-phosphatidyl-1D-myo-inositol 3-phosphate = PtdIns3P
1-phosphatidyl-1D-myo-inositol 4-phosphate = PtdIns4P
1-phosphatidyl-1D-myo-inositol 3,4-bisphosphate = PtdIns(3,4)P2
1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate = PtdIns(4,5)P2
1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate = PtdIns(3,4,5)P3
Other name(s): type I phosphoinositide 3-kinase
Systematic name: ATP:1-phosphatidyl-1D-myo-inositol-4,5-bisphosphate 3-phosphotransferase
Comments: This enzyme also catalyses the phosphorylation of PtdIns4P to PtdIns(3,4)P2, and of PtdIns to PtdIns3P. Four mammalian isoforms are known to exist.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 103843-30-7
References:
1.  Vanhaesebroeck, B., Leevers, S.J., Ahmadi, K., Timms, J., Katso, R., Driscoll, P.C., Woscholski, R., Parker, P.J. and Waterfield, M.D. Synthesis and function of 3-phosphorylated inositol lipids. Annu. Rev. Biochem. 70 (2001) 535–602. [DOI] [PMID: 11395417]
[EC 2.7.1.153 created 2002]
 
 
EC 3.2.1.215     Relevance: 94.5%
Accepted name: arabinogalactan exo α-(1,3)-α-D-galactosyl-(1→3)-L-arabinofuranosidase (non-reducing end)
Reaction: Hydrolysis of α-D-Galp-(1→3)-L-Araf disaccharides from non-reducing terminals in branches of type II arabinogalactan attached to proteins.
Glossary: Araf = arabinofuranose
Arap = arabinopyranose
Galp = galactopyranose
Other name(s): 3-O-α-D-galactosyl-α-L-arabinofuranosidase
Systematic name: type II arabinogalactan exo α-(1,3)-[α-D-galactosyl-(1→3)-L-arabinofuranose] hydrolase (non-reducing end)
Comments: The enzyme, characterized from the bacterium Bifidobacterium longum, specifically hydrolyses α-D-Galp-(1→3)-L-Araf disaccharides from the non-reducing terminal of arabinogalactan using an exo mode of action. It is particularly active with gum arabic arabinogalactan, a type II arabinogalactan produced by acacia trees. The enzyme can also hydrolyse β-L-Arap-(1→3)-L-Araf disaccharides, but this activity is significantly lower.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Sasaki, Y., Horigome, A., Odamaki, T., Xiao, J.Z., Ishiwata, A., Ito, Y., Kitahara, K. and Fujita, K. Characterization of a novel 3-O-α-D-galactosyl-α-L-arabinofuranosidase for the assimilation of gum arabic AGP in Bifidobacterium longum subsp. longum. Appl. Environ. Microbiol. (2021) . [DOI] [PMID: 33674431]
[EC 3.2.1.215 created 2021]
 
 
EC 2.7.1.158     Relevance: 94.2%
Accepted name: inositol-pentakisphosphate 2-kinase
Reaction: ATP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate = ADP + 1D-myo-inositol hexakisphosphate
Other name(s): IP5 2-kinase; Gsl1p; Ipk1p; inositol polyphosphate kinase; inositol 1,3,4,5,6-pentakisphosphate 2-kinase; Ins(1,3,4,5,6)P5 2-kinase
Systematic name: ATP:1D-myo-inositol 1,3,4,5,6-pentakisphosphate 2-phosphotransferase
Comments: The enzyme can also use Ins(1,4,5,6)P4 [2] and Ins(1,4,5)P3 [3] as substrate. Inositol hexakisphosphate (phytate) accumulates in storage protein bodies during seed development and, when hydrolysed, releases stored nutrients to the developing seedling before the plant is capable of absorbing nutrients from its environment [5].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  York, J.D., Odom, A.R., Murphy, R., Ives, E.B. and Wente, S.R. A phospholipase C-dependent inositol polyphosphate kinase pathway required for efficient messenger RNA export. Science 285 (1999) 96–100. [DOI] [PMID: 10390371]
2.  Phillippy, B.Q., Ullah, A.H. and Ehrlich, K.C. Purification and some properties of inositol 1,3,4,5,6-Pentakisphosphate 2-kinase from immature soybean seeds. J. Biol. Chem. 269 (1994) 28393–28399. [PMID: 7961779]
3.  Phillippy, B.Q., Ullah, A.H. and Ehrlich, K.C. Additions and corrections to Purification and some properties of inositol 1,3,4,5,6-pentakisphosphate 2-kinase from immature soybean seeds. J. Biol. Chem. 270 (1997) 7782.
4.  Ongusaha, P.P., Hughes, P.J., Davey, J. and Michell, R.H. Inositol hexakisphosphate in Schizosaccharomyces pombe: synthesis from Ins(1,4,5)P3 and osmotic regulation. Biochem. J. 335 (1998) 671–679. [PMID: 9794810]
5.  Miller, A.L., Suntharalingam, M., Johnson, S.L., Audhya, A., Emr, S.D. and Wente, S.R. Cytoplasmic inositol hexakisphosphate production is sufficient for mediating the Gle1-mRNA export pathway. J. Biol. Chem. 279 (2004) 51022–51032. [DOI] [PMID: 15459192]
6.  Stevenson-Paulik, J., Odom, A.R. and York, J.D. Molecular and biochemical characterization of two plant inositol polyphosphate 6-/3-/5-kinases. J. Biol. Chem. 277 (2002) 42711–42718. [DOI] [PMID: 12226109]
[EC 2.7.1.158 created 2006]
 
 
EC 2.4.3.9     Relevance: 93.6%
Accepted name: lactosylceramide α-2,3-sialyltransferase
Reaction: CMP-N-acetylneuraminate + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = CMP + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of ganglioside biosynthesis (pathway to GM2), click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): cytidine monophosphoacetylneuraminate-lactosylceramide α2,3- sialyltransferase; CMP-acetylneuraminate-lactosylceramide-sialyltransferase; CMP-acetylneuraminic acid:lactosylceramide sialyltransferase; CMP-sialic acid:lactosylceramide-sialyltransferase; cytidine monophosphoacetylneuraminate-lactosylceramide sialyltransferase; ganglioside GM3 synthetase; GM3 synthase; GM3 synthetase; SAT 1; CMP-N-acetylneuraminate:lactosylceramide α-2,3-N-acetylneuraminyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide α-(2→3)-N-acetylneuraminyltransferase
Systematic name: CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide α-(2→3)-N-acetylneuraminyltransferase
Comments: Lactose cannot act as acceptor.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 125752-90-1
References:
1.  Basu, S., Kaufman, B. and Roseman, S. Enzymatic synthesis of glucocerebroside by a glucosyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1388–1394. [PMID: 4631392]
2.  Fishman, P.H., Bradley, R.M. and Henneberry, R.C. Butyrate-induced glycolipid biosynthesis in HeLa cells: properties of the induced sialyltransferase. Arch. Biochem. Biophys. 172 (1976) 618–626. [DOI] [PMID: 4022]
3.  Higashi, H., Basu, M. and Basu, S. Biosynthesis in vitro of disialosylneolactotetraosylceramide by a solubilized sialyltransferase from embryonic chicken brain. J. Biol. Chem. 260 (1985) 824–828. [PMID: 3838172]
[EC 2.4.3.9 created 1984 as EC 2.4.99.9, modified 1986, transferred 2022 to EC 2.4.3.9]
 
 
EC 2.7.1.149     Relevance: 93.3%
Accepted name: 1-phosphatidylinositol-5-phosphate 4-kinase
Reaction: ATP + 1-phosphatidyl-1D-myo-inositol 5-phosphate = ADP + 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate
For diagram of 1-phosphatidyl-myo-inositol metabolism (part 2), click here
Glossary: 1-phosphatidyl-1D-myo-inositol 5-phosphate = PtdIns5P
1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate = PtdIns(4,5)P2
Other name(s): type II PIP kinase
Systematic name: ATP:1-phosphatidyl-1D-myo-inositol-5-phosphate 4-phosphotransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 247907-17-1
References:
1.  Rameh, L.E., Tolias, K.F., Duckworth, B.C. and Cantley, L.C. A new pathway for synthesis of phosphatidylinositol-4,5-bisphosphate. Nature 390 (1997) 192–196. [DOI] [PMID: 9367159]
[EC 2.7.1.149 created 2002]
 
 
EC 3.5.1.89     Relevance: 93.3%
Accepted name: N-acetylglucosaminylphosphatidylinositol deacetylase
Reaction: 6-(N-acetyl-α-D-glucosaminyl)-1-phosphatidyl-1D-myo-inositol + H2O = 6-(α-D-glucosaminyl)-1-phosphatidyl-1D-myo-inositol + acetate
For diagram of glycosylphosphatidyl-myo-inositol biosynthesis, click here
Other name(s): N-acetyl-D-glucosaminylphosphatidylinositol acetylhydrolase; N-acetylglucosaminylphosphatidylinositol de-N-acetylase; GlcNAc-PI de-N-acetylase; GlcNAc-PI deacetylase; acetylglucosaminylphosphatidylinositol deacetylase
Systematic name: 6-(N-acetyl-α-D-glucosaminyl)-1-phosphatidyl-1D-myo-inositol acetylhydrolase
Comments: Involved in the second step of glycosylphosphatidylinositol (GPI) anchor formation in all eukaryotes. The enzyme appears to be composed of a single subunit (PIG-L in mammalian cells and GPI12 in yeast). In some species, the long-chain sn-1-acyl group of the phosphatidyl group is replaced by a long-chain alkyl or alk-1-enyl group.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 122191-30-4
References:
1.  Doering, T.L., Masteron, W.J., Englund, P.T. and Hart, G.W. Biosynthesis of the glycosyl phosphatidylinositol membrane anchor of the trypanosome variant surface glycoprotein. Origin of the non-acetylated glucosamine. J. Biol. Chem. 264 (1989) 11168–11173. [PMID: 2525555]
2.  Nakamura, N., Inoue, N., Watanabe, R., Takahashi, M., Takeda, J., Stevens, V.L. and Kinoshita, T. Expression cloning of PIG-L, a candidate N-acetylglucosaminyl-phosphatidylinositol deacetylase. J. Biol. Chem. 272 (1997) 15834–15840. [DOI] [PMID: 9188481]
3.  Watanabe, R., Ohishi, K., Maeda, Y., Nakamura, N. and Kinoshita, T. Mammalian PIG-L and its yeast homologue Gpi12p are N-acetylglucosaminylphosphatidylinositol de-N-acetylases essential in glycosylphosphatidylinositol biosynthesis. Biochem. J. 339 (1999) 185–192. [PMID: 10085243]
4.  Smith, T.K, Crossman, A., Borissow, C.N., Paterson, M.J., Dix, A., Brimacombe, J.S. and Ferguson, M.A.J. Specificity of GlcNAc-PI de-N-acetylase of GPI biosynthesis and synthesis of parasite-specific suicide substrate inhibitors. EMBO J. 20 (2001) 3322–3332. [DOI] [PMID: 11432820]
[EC 3.5.1.89 created 1992 as EC 3.1.1.69, transferred 2002 to EC 3.5.1.89, modified 2002]
 
 
EC 3.2.1.110      
Deleted entry: mucinaminylserine mucinaminidase. The enzyme is identical to EC 3.2.1.97, glycopeptide α-N-acetylgalactosaminidase
[EC 3.2.1.110 created 1984, deleted 2008]
 
 
EC 2.4.99.9      
Transferred entry: lactosylceramide α-2,3-sialyltransferase. Now EC 2.4.3.9, lactosylceramide α-2,3-sialyltransferase
[EC 2.4.99.9 created 1984, modified 1986, deleted 2022]
 
 
EC 2.4.1.69     Relevance: 93%
Accepted name: type 1 galactoside α-(1,2)-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = GDP + α-L-fucosyl-(1→2)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R
For diagram of lactotetraosylceramide biosynthesis, click here
Other name(s): galactoside 2-α-L-fucosyltransferase (ambiguous); blood group H α-2-fucosyltransferase (ambiguous); guanosine diphosphofucose-galactoside 2-L-fucosyltransferase; α-(1→2)-L-fucosyltransferase (ambiguous); α-2-fucosyltransferase (ambiguous); α-2-L-fucosyltransferase (ambiguous); blood-group substance H-dependent fucosyltransferase (ambiguous); guanosine diphosphofucose-glycoprotein 2-α-fucosyltransferase (ambiguous); guanosine diphosphofucose-β-D-galactosyl-α-2-L-fucosyltransferase (ambiguous); guanosine diphosphofucose-galactosylacetylglucosaminylgalactosylglucosylceramide α-L-fucosyltransferase (ambiguous); guanosine diphosphofucose-glycoprotein 2-α-L-fucosyltransferase (ambiguous); secretor-type β-galactoside α1→2fucosyltransferase; β-galactoside α1→2fucosyltransferase (ambiguous); GDP-β-L-fucose:β-D-galactosyl-R 2-α-L-fucosyltransferase (ambiguous); FUT2 (gene name); GDP-β-L-fucose:β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 2-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R α-(1,2)-L-fucosyltransferase (configuration-inverting)
Comments: The enzyme acts on a glycoconjugates where R (see reaction) is a glycoprotein or glycosphingolipid. The recognized moiety of the substrate is known as a type 1 histo-blood group antigen precursor disaccharide, and the action of the enzyme produces an H type 1 antigen. In humans the main enzyme performing this reaction is encoded by the FUT2 gene (also known as the Secretor gene), which is also able to act on type 2 substrates (see EC 2.4.1.344). The enzyme from the bacterium Helicobacter pylori cannot act on type 2 substrates.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 56093-23-3
References:
1.  Beyer, T.A. and Hill, R.L. Enzymatic properties of the β-galactoside α1→2 fucosyltransferase from porcine submaxillary gland. J. Biol. Chem. 255 (1980) 5373–5379. [PMID: 7372640]
2.  Beyer, T.A., Sadler, J.E. and Hill, R.L. Purification to homogeneity of H blood group β-galactoside α1→2 fucosyltransferase from porcine submaxillary gland. J. Biol. Chem. 255 (1980) 5364–5372. [PMID: 6246105]
3.  Kumazaki, T. and Yoshida, A. Biochemical evidence that secretor gene, Se, is a structural gene encoding a specific fucosyltransferase. Proc. Natl. Acad. Sci. USA 81 (1984) 4193–4197. [DOI] [PMID: 6588382]
4.  Koda, Y., Soejima, M., Wang, B. and Kimura, H. Structure and expression of the gene encoding secretor-type galactoside 2-α-L-fucosyltransferase (FUT2). Eur. J. Biochem. 246 (1997) 750–755. [DOI] [PMID: 9219535]
5.  Wang, G., Boulton, P.G., Chan, N.W., Palcic, M.M. and Taylor, D.E. Novel Helicobacter pylori α1,2-fucosyltransferase, a key enzyme in the synthesis of Lewis antigens. Microbiology 145 (1999) 3245–3253. [DOI] [PMID: 10589734]
[EC 2.4.1.69 created 1972 (EC 2.4.1.89 created 1976, incorporated 1984), modified 2002, modified 2017]
 
 
EC 6.3.1.13     Relevance: 92.9%
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
For diagram of mycothiol biosynthesis, click here
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].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
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. [DOI] [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. [DOI] [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. [DOI] [PMID: 19053270]
[EC 6.3.1.13 created 2009]
 
 
EC 2.7.1.140     Relevance: 92.1%
Accepted name: inositol-tetrakisphosphate 5-kinase
Reaction: ATP + 1D-myo-inositol 1,3,4,6-tetrakisphosphate = ADP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate
Other name(s): 1D-myo-inositol-tetrakisphosphate 5-kinase
Systematic name: ATP:1D-myo-inositol-1,3,4,6-tetrakisphosphate 5-phosphotransferase
Comments: The enzyme from plants and yeast can also use Ins(1,2,3,4,6)P5 as a substrate [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 123940-40-9
References:
1.  Shears, S.B. The pathway of myo-inositol 1,3,4-trisphosphate phosphorylation in liver. Identification of myo-inositol 1,3,4-trisphosphate 6-kinase, myo-inositol 1,3,4-trisphosphate 5-kinase, and myo-inositol 1,3,4,6-tetrakisphosphate 5-kinase. J. Biol. Chem. 264 (1989) 19879–19886. [PMID: 2584198]
2.  Stevenson-Paulik, J., Odom, A.R. and York, J.D. Molecular and biochemical characterization of two plant inositol polyphosphate 6-/3-/5-kinases. J. Biol. Chem. 277 (2002) 42711–42718. [DOI] [PMID: 12226109]
[EC 2.7.1.140 created 1992]
 
 
EC 2.4.3.8     Relevance: 92%
Accepted name: α-N-acetylneuraminate α-2,8-sialyltransferase
Reaction: CMP-N-acetylneuraminate + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-R = CMP + α-N-acetylneuraminyl-(2→8)-α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-R
For diagram of ganglioside biosynthesis (pathway to GD3), click here
Other name(s): cytidine monophosphoacetylneuraminate-ganglioside GM3; α-2,8-sialyltransferase; ganglioside GD3 synthase; ganglioside GD3 synthetase sialyltransferase; CMP-NeuAc:LM1(α2-8) sialyltranferase; GD3 synthase; SAT-2
Systematic name: CMP-N-acetylneuraminate:α-N-acetylneuraminyl-(2→3)-β-D-galactoside α-(2→8)-N-acetylneuraminyltransferase
Comments: Gangliosides act as acceptors.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 67339-00-8
References:
1.  Eppler, M.C., Morré, J.D. and Keenan, T.W. Ganglioside biosynthesis in rat liver: alteration of sialyltransferase activities by nucleotides. Biochim. Biophys. Acta 619 (1980) 332–343. [DOI] [PMID: 7407217]
2.  Higashi, H., Basu, M. and Basu, S. Biosynthesis in vitro of disialosylneolactotetraosylceramide by a solubilized sialyltransferase from embryonic chicken brain. J. Biol. Chem. 260 (1985) 824–828. [PMID: 3838172]
3.  McCoy, R.D., Vimr, E.R. and Troy, F.A. CMP-NeuNAc:poly-α-2,8-sialosyl sialyltransferase and the biosynthesis of polysialosyl units in neural cell adhesion molecules. J. Biol. Chem. 260 (1985) 12695–12699. [PMID: 4044605]
4.  Yohe, H.C. and Yu, R.K. In vitro biosynthesis of an isomer of brain trisialoganglioside, GT1a. J. Biol. Chem. 255 (1980) 608–613. [PMID: 6766128]
[EC 2.4.3.8 created 1984 as EC 2.4.99.8, modified 1986, transferred 2022 to EC 2.4.3.8]
 
 
EC 2.4.99.8      
Transferred entry: α-N-acetylneuraminate α-2,8-sialyltransferase. Now EC 2.4.3.8, α-N-acetylneuraminate α-2,8-sialyltransferase
[EC 2.4.99.8 created 1984, modified 1986, deleted 2022]
 
 
EC 2.4.1.275     Relevance: 91.4%
Accepted name: neolactotriaosylceramide β-1,4-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of neolactotetraosylceramide biosynthesis, click here
Glossary: N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = neolactotriaosylceramide
Other name(s): β4Gal-T4; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide β-1,4-galactosyltransferase; lactotriaosylceramide β-1,4-galactosyltransferase (incorrect)
Systematic name: UDP-α-D-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-D-galactosyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Schwientek, T., Almeida, R., Levery, S.B., Holmes, E.H., Bennett, E. and Clausen, H. Cloning of a novel member of the UDP-galactose:β-N-acetylglucosamine β1,4-galactosyltransferase family, β4Gal-T4, involved in glycosphingolipid biosynthesis. J. Biol. Chem. 273 (1998) 29331–29340. [DOI] [PMID: 9792633]
[EC 2.4.1.275 created 2011, modified 2013]
 
 
EC 2.4.1.150     Relevance: 91.3%
Accepted name: N-acetyllactosaminide β-1,6-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-Gal-(1→4)-β-D-GlcNAc-(1→3)-β-D-Gal-(1→4)-β-D-GlcNAc-R = UDP + β-D-Gal-(1→4)-β-D-GlcNAc-(1→3)-[β-D-GlcNAc-(1→6)]-β-D-Gal-(1→4)-β-D-GlcNAc-R
Glossary: β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-R = type 2 precursor disaccharide
Other name(s): GCNT2 (gene name); GCNT3 (gene name); IGnT; I-branching β1,6-N-acetylglucosaminyltransferase; N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-acetyllactosaminide β1→6-acetylglucosaminyltransferase; Galβ1→4GlcNAc-R β1→6 N-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-1,4-N-acetyl-D-glucosaminide β-1,6-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminide 6-β-N-acetylglucosaminyltransferase (configuration-inverting)
Comments: The enzyme acts on poly-N-acetyllactosamine [glycan chains of β-D-galactosyl-(1→4)-N-acetyl-D-glucosamine units connected by β(1,3) linkages] attached to proteins or lipids. It transfers a GlcNAc residue by β(1,6)-linkage to galactosyl residues close to non-reducing terminals, introducing a branching pattern known as I branching.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 85638-40-0
References:
1.  Van den Eijnden, D.H., Winterwerp, H., Smeeman, P. and Schiphorst, W.E.C.M. Novikoff ascites tumor cells contain N-acetyllactosaminide β1→3 and β1→6 N-acetylglucosaminyltransferase activity. J. Biol. Chem. 258 (1983) 3435–3437. [PMID: 6219989]
2.  Basu, M. and Basu, S. Biosynthesis in vitro of Ii core glycosphingolipids from neolactotetraosylceramide by β 1-3- and β 1-6-N-acetylglucosaminyltransferases from mouse T-lymphoma. J. Biol. Chem. 259 (1984) 12557–12562. [PMID: 6238026]
3.  Piller, F., Cartron, J.P., Maranduba, A., Veyrieres, A., Leroy, Y. and Fournet, B. Biosynthesis of blood group I antigens. Identification of a UDP-GlcNAc:GlcNAc β1-3Gal(-R) β1-6(GlcNAc to Gal) N-acetylglucosaminyltransferase in hog gastric mucosa. J. Biol. Chem. 259 (1984) 13385–13390. [PMID: 6490658]
4.  Bierhuizen, M.F., Maemura, K., Kudo, S. and Fukuda, M. Genomic organization of core 2 and I branching β-1,6-N-acetylglucosaminyltransferases. Implication for evolution of the β-1,6-N-acetylglucosaminyltransferase gene family. Glycobiology 5 (1995) 417–425. [DOI] [PMID: 7579796]
5.  Ujita, M., McAuliffe, J., Suzuki, M., Hindsgaul, O., Clausen, H., Fukuda, M.N. and Fukuda, M. Regulation of I-branched poly-N-acetyllactosamine synthesis. Concerted actions by I-extension enzyme, I-branching enzyme, and β1,4-galactosyltransferase I. J. Biol. Chem. 274 (1999) 9296–9304. [DOI] [PMID: 10092606]
6.  Yeh, J.C., Ong, E. and Fukuda, M. Molecular cloning and expression of a novel β-1,6-N-acetylglucosaminyltransferase that forms core 2, core 4, and I branches. J. Biol. Chem. 274 (1999) 3215–3221. [DOI] [PMID: 9915862]
[EC 2.4.1.150 created 1984 (EC 2.4.1.164 created 1989, incorporated 2016), modified 2017]
 
 
EC 2.4.1.37     Relevance: 90.9%
Accepted name: fucosylgalactoside 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + α-L-fucosyl-(1→2)-D-galactosyl-R = UDP + α-D-galactosyl-(1→3)-[α-L-fucosyl(1→2)]-D-galactosyl-R (where R can be OH, an oligosaccharide or a glycoconjugate)
Other name(s): UDP-galactose:O-α-L-fucosyl(1→2)D-galactose α-D-galactosyltransferase; UDPgalactose:glycoprotein-α-L-fucosyl-(1,2)-D-galactose 3-α-D-galactosyltransferase; [blood group substance] α-galactosyltransferase; blood-group substance B-dependent galactosyltransferase; glycoprotein-fucosylgalactoside α-galactosyltransferase; histo-blood group B transferase; histo-blood substance B-dependent galactosyltransferase; UDP-galactose:α-L-fucosyl-1,2-D-galactoside 3-α-D-galactosyltransferase; UDP-galactose:α-L-fucosyl-(1→2)-D-galactoside 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:α-L-fucosyl-(1→2)-D-galactoside 3-α-D-galactosyltransferase
Comments: Acts on blood group substance, and can use a number of 2-fucosyl-galactosides as acceptors.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37257-33-3
References:
1.  Race, C., Ziderman, D. and Watkins, W.M. An α-D-galactosyltransferase associated with the blood-group B character. Biochem. J. 107 (1968) 733–735. [PMID: 16742598]
[EC 2.4.1.37 created 1972, modified 1999, modified 2002]
 
 
EC 3.1.3.86     Relevance: 90.8%
Accepted name: phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase
Reaction: 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate + H2O = 1-phosphatidyl-1D-myo-inositol 3,4-bisphosphate + phosphate
For diagram of 1-phosphatidyl-myo-inositol metabolism, click here
Glossary: 1-phosphatidyl-1D-myo-inositol 3,4-bisphosphate = PtdIns(3,4)P2
1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate = PtdIns(3,4,5)P3
1-phosphatidyl-1D-myo-inositol 1,3,4,5-trisphosphate = PtdIns(1,3,4,5)P4
Other name(s): SHIP1; SHIP2; SHIP; p150Ship
Systematic name: 1-phosphatidyl-1D-myo-inositol-3,4,5-trisphosphate 5-phosphohydrolase
Comments: This enzyme hydrolyses 1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) to produce PtdIns(3,4)P2, thereby negatively regulating the PI3K (phosphoinositide 3-kinase) pathways. The enzyme also shows activity toward (PtdIns(1,3,4,5)P4) [5]. The enzyme is involved in several signal transduction pathways in the immune system leading to an adverse range of effects.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB
References:
1.  Lioubin, M.N., Algate, P.A., Tsai, S., Carlberg, K., Aebersold, A. and Rohrschneider, L.R. p150Ship, a signal transduction molecule with inositol polyphosphate-5-phosphatase activity. Genes Dev. 10 (1996) 1084–1095. [DOI] [PMID: 8654924]
2.  Damen, J.E., Liu, L., Rosten, P., Humphries, R.K., Jefferson, A.B., Majerus, P.W. and Krystal, G. The 145-kDa protein induced to associate with Shc by multiple cytokines is an inositol tetraphosphate and phosphatidylinositol 3,4,5-triphosphate 5-phosphatase. Proc. Natl. Acad. Sci. USA 93 (1996) 1689–1693. [DOI] [PMID: 8643691]
3.  Giuriato, S., Payrastre, B., Drayer, A.L., Plantavid, M., Woscholski, R., Parker, P., Erneux, C. and Chap, H. Tyrosine phosphorylation and relocation of SHIP are integrin-mediated in thrombin-stimulated human blood platelets. J. Biol. Chem. 272 (1997) 26857–26863. [DOI] [PMID: 9341117]
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[EC 3.1.3.86 created 2011]
 
 


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