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 methylation of 3-phospho-¦Á-D-Man-(1¡ú2)-¦Á-D-Man-(1¡ú2)-[¦Á-D-Man-(1¡ú3)-¦Á-D-Man-(1¡ú3)-¦Á-D-Man-(1¡ú2)-¦Á-D-Man-(1¡ú2)]n-¦Á-D-Man-(1¡ú3)-¦Á-D-Man-(1¡ú3)-¦Á-D-Man-(1¡ú3)-¦Á-D-GlcNAc-diphospho-ditrans,octacis-undecaprenol (cf. EC?2.1.1.294, 3-O-phospho-polymannosyl GlcNAc-diphospho-ditrans,octacis-undecaprenol 3-phospho-methyltransferase).
