Reaction: S-adenosyl-L-methionine + 3-O-phospho-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 = S-adenosyl-L-homocysteine + 3-O-methylphospho-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
Other name(s): WbdD; S-adenosyl-L-methionine:3-O-phospho-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)-α-D-Man-(1→3)-α-D-Man-(1→3)]n-α-D-Man-(1→3)-α-D-Man-(1→3)-α-D-GlcNAc-α-diphospho-ditrans,octacis-undecaprenol 3-phospho-methyltransferase
Systematic name: S-adenosyl-L-methionine:3-O-phospho-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 3-phospho-methyltransferase
Comments: The enzyme is involved in the biosynthesis of the polymannose O-polysaccharide in the outer leaflet of the membrane of Escherichia coli serotype O9a. O-Polysaccharide structures vary extensively because of differences in the number and type of sugars in the repeat unit. The dual kinase/methylase WbdD also catalyses the preceding phosphorylation of 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 (cf. EC 2.7.1.181, polymannosyl GlcNAc-diphospho-ditrans,octacis-undecaprenol kinase).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Clarke, B.R., Cuthbertson, L. and Whitfield, C. Nonreducing terminal modifications determine the chain length of polymannose O antigens of Escherichia coli and couple chain termination to polymer export via an ATP-binding cassette transporter. J. Biol. Chem. 279 (2004) 35709-35718. [PMID: 15184370]
2. Clarke, B.R., Greenfield, L.K., Bouwman, C. and Whitfield, C. Coordination of polymerization, chain termination, and export in assembly of the Escherichia coli lipopolysaccharide O9a antigen in an ATP-binding cassette transporter-dependent pathway. J. Biol. Chem. 284 (2009) 30662-30672. [PMID: 19734145]
3. Clarke, B.R., Richards, M.R., Greenfield, L.K., Hou, D., Lowary, T.L. and Whitfield, C. In vitro reconstruction of the chain termination reaction in biosynthesis of the Escherichia coli O9a O-polysaccharide: the chain-length regulator, WbdD, catalyzes the addition of methyl phosphate to the non-reducing terminus of the growing glycan. J. Biol. Chem. 286 (2011) 41391-41401. [PMID: 21990359]
4. 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]