KEGG   ENZYME: 2.4.1.125Help
Entry
EC 2.4.1.125                Enzyme                                 

Name
sucrose---1,6-alpha-glucan 3(6)-alpha-glucosyltransferase;
water-soluble-glucan synthase (misleading);
GTF-I;
GTF-S;
GTF-SI;
sucrose-1,6-alpha-glucan 3(6)-alpha-glucosyltransferase;
sucrose:1,6-alpha-D-glucan 3-alpha- and 6-alpha-glucosyltransferase;
sucrose:1,6-, 1,3-alpha-D-glucan 3-alpha- and 6-alpha-D-glucosyltransferase;
sucrose:1,6-alpha-D-glucan 3(6)-alpha-D-glucosyltransferase;
gtfB (gene name);
gtfC (gene name);
gtfD (gene name)
Class
Transferases;
Glycosyltransferases;
Hexosyltransferases
BRITE hierarchy
Sysname
sucrose:(1->6)-alpha-D-glucan 3(6)-alpha-D-glucosyltransferase
Reaction(IUBMB)
(1) sucrose + [(1->6)-alpha-D-glucosyl]n = D-fructose + [(1->6)-alpha-D-glucosyl]n+1  [RN:R02120 R06066];
(2) sucrose + [(1->6)-alpha-D-glucosyl]n = D-fructose + (1->3)-alpha-D-glucosyl[(1->6)-alpha-D-glucosyl]n
Reaction(KEGG)
Substrate
sucrose [CPD:C00089];
[(1->6)-alpha-D-glucosyl]n
Product
D-fructose [CPD:C00095];
[(1->6)-alpha-D-glucosyl]n+1;
(1->3)-alpha-D-glucosyl[(1->6)-alpha-D-glucosyl]n
Comment
The enzyme was characterized from the dental caries bacterium Streptococcus mutans. It transfers glucosyl residues from sucrose to either the 6- or the 3-positions of glucose residues in glucans, producing a highly-branched extracellular D-glucan polymers that promote attachment of the bacteria to teeth. Three types of the enzyme have been described; the insoluble polymers produced by GTF-I and GTF-SI contain 85% alpha(1->3) bonds and 15% alpha(1->6) bonds, while the soluble polymers produced by GTF-S contain only 30% of alpha(1->3) bonds and 70% alpha(1->6) bonds. cf. EC 2.4.1.5, dextransucrase [5].
History
EC 2.4.1.125 created 1984
Reference
1  [PMID:6216919]
  Authors
Mukasa H, Shimamura A, Tsumori H.
  Title
Purification and characterization of basic glucosyltransferase from Streptococcus mutans serotype c.
  Journal
Biochim. Biophys. Acta. 719 (1982) 81-9.
Reference
2  [PMID:6461359]
  Authors
Shimamura A, Tsumori H, Mukasa H.
  Title
Purification and properties of Streptococcus mutans extracellular glucosyltransferase.
  Journal
Biochim. Biophys. Acta. 702 (1982) 72-80.
Reference
3  [PMID:2937877]
  Authors
Tsumori H, Shimamura A, Mukasa H.
  Title
Purification and properties of extracellular glucosyltransferase synthesizing 1,6-, 1,3-alpha-D-glucan from Streptococcus mutans serotype a.
  Journal
J. Gen. Microbiol. 131 (1985) 3347-53.
Reference
4  [PMID:8737492]
  Authors
Fujiwara T, Tamesada M, Bian Z, Kawabata S, Kimura S, Hamada S
  Title
Deletion and reintroduction of glucosyltransferase genes of Streptococcus mutans  and role of their gene products in sucrose dependent cellular adherence.
  Journal
Microb. Pathog. 20 (1996) 225-33.
Reference
5  [PMID:10234842]
  Authors
Monchois V, Willemot RM, Monsan P
  Title
Glucansucrases: mechanism of action and structure-function relationships.
  Journal
FEMS. Microbiol. Rev. 23 (1999) 131-51.
Reference
6  [PMID:21354427]
  Authors
Ito K, Ito S, Shimamura T, Weyand S, Kawarasaki Y, Misaka T, Abe K, Kobayashi T, Cameron AD, Iwata S
  Title
Crystal structure of glucansucrase from the dental caries pathogen Streptococcus  mutans.
  Journal
J. Mol. Biol. 408 (2011) 177-86.
Other DBs
ExplorEnz - The Enzyme Database: 
IUBMB Enzyme Nomenclature: 
ExPASy - ENZYME nomenclature database: 
BRENDA, the Enzyme Database: 
CAS: 
81725-87-3

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