Reaction: sucrose + a (1→6)-α-D-glucan = D-fructose + a (1→6)-α-D-glucan containing a (1→2)-α-D-glucose branch
Systematic name: sucrose:(1→6)-α-D-glucan 2-α-D-glucosyl-transferase
Comments: The glucansucrases transfer a D-glusosyl residue from sucrose to a glucan chain. They are classified based on the linkage by which they attach the transferred residue. In some cases, in which the enzyme forms more than one linkage type, classification relies on the relative proportion of the linkages that are generated. Currently classified glucansucrases include EC 2.4.1.372, mutansucrase, which extends (1→3)-α-D-glucans; EC 2.4.1.4, amylosucrase, which extends (1→4)-α-D-glucans; EC 2.4.1.5, dextransucrase, which extends (1→6) α-D-glucans; EC 2.4.1.373, α-(1→2) branching sucrase, which introduces α(1→2) branches into (1→6)-α-D-glucans; EC 2.4.1.125, sucrose—1,6-α-glucan 3(6)-α-glucosyltransferase, which extends (1→6) α-D-glucans by both α(1→3) and α(1→6) linkages, with one of the linkage types being dominant; and EC 2.4.1.140, alternansucrase, which forms both α(1→3) and α(1→6) linkages in approximately equal amounts by alternating the linkage type.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Fabre, E., Bozonnet, S., Arcache, A., Willemot, R.M., Vignon, M., Monsan, P. and Remaud-Simeon, M. Role of the two catalytic domains of DSR-E dextransucrase and their involvement in the formation of highly α-1,2 branched dextran. J. Bacteriol. 187 (2005) 296-303. [PMID: 15601714]
2. Brison, Y., Laguerre, S., Lefoulon, F., Morel, S., Monties, N., Potocki-Veronese, G., Monsan, P. and Remaud-Simeon, M. Branching pattern of gluco-oligosaccharides and 1.5kDa dextran grafted by the α-1,2 branching sucrase GBD-CD2. Carbohydr Polym 94 (2013) 567-576. [PMID: 23544576]
3. Passerini, D., Vuillemin, M., Ufarte, L., Morel, S., Loux, V., Fontagne-Faucher, C., Monsan, P., Remaud-Simeon, M. and Moulis, C. Inventory of the GH70 enzymes encoded by Leuconostoc citreum NRRL B-1299 - identification of three novel α-transglucosylases. FEBS J. 282 (2015) 2115-2130. [PMID: 25756290]