The glycosyltransferase WecG/TagA superfamily contains Escherichia coli WecG, Bacillus subtilis TagA and related proteins. E. coli WecG is believed to be a UDP-N-acetyl-D-mannosaminuronic acid transferase, and is involved in enterobacterial common antigen (eca) synthesis. B. subtilis TagA plays a key role in the Wall Teichoic Acid (WTA) biosynthetic pathway, catalyzing the transfer of N-acetylmannosamine to the C4 hydroxyl of a membrane-anchored N-acetylglucosaminyl diphospholipid to make ManNAc-beta-(1,4)-GlcNAc-pp-undecaprenyl. This is the first committed step in this pathway. Also included in this group is Xanthomonas campestris pv. campestris GumM, a glycosyltransferase participating in the biosynthesis of the exopolysaccharide xanthan.