Reaction: (1) 2 GDP-α-D-mannose + [α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol = 2 GDP + α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
(2) 2 GDP-α-D-mannose + α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol = 2 GDP + [α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n+1-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol
Other name(s): WbdA
Systematic name: GDP-α-D-mannose:α-D-Man-(1→2)-α-D-Man-(1→2)-[α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→2)-α-D-Man-(1→2)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol 2,3-α-mannosyltransferase (configuration-retaining)
Comments: The enzyme is involved in the biosynthesis of polymannose O-polysaccharide in the outer leaflet of the membrane of Escherichia coli serotype O9a. The enzymes consists of two domains that are responsible for the 1→2 and 1→3 linkages, respectively.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Greenfield, L.K., Richards, M.R., Li, J., Wakarchuk, W.W., Lowary, T.L. and Whitfield, C. Biosynthesis of the polymannose lipopolysaccharide O-antigens from Escherichia coli serotypes O8 and O9a requires a unique combination of single- and multiple-active site mannosyltransferases. J. Biol. Chem. 287 (2012) 35078-35091. [PMID: 22875852]
2. Greenfield, L.K., Richards, M.R., Vinogradov, E., Wakarchuk, W.W., Lowary, T.L. and Whitfield, C. Domain organization of the polymerizing mannosyltransferases involved in synthesis of the Escherichia coli O8 and O9a lipopolysaccharide O-antigens. J. Biol. Chem. 287 (2012) 38135-38149. [PMID: 22989876]
3. Liston, S.D., Clarke, B.R., Greenfield, L.K., Richards, M.R., Lowary, T.L. and Whitfield, C. Domain interactions control complex formation and polymerase specificity in the biosynthesis of the Escherichia coli O9a antigen. J. Biol. Chem. 290 (2015) 1075-1085. [PMID: 25422321]