The members of this subfamily catalyze the formation of a phosphodiester bond between a membrane-associated undecaprenyl-phosphate (Und-P) molecule and N-acetylhexosamine 1-phosphate, which is usually donated by a soluble UDP-N-acetylhexosamine precursor. The WbcO/WbpL substrate specificity has not yet been determined, but the structure of their biosynthetic end products implies that UDP-N-acetyl-D-fucosamine (UDP-FucNAc) and/or UDPN-acetyl-D-quinosamine (UDP-QuiNAc) are used. The subgroup of bacterial UDP-HexNAc:polyprenol-P HexNAc-1-P transferases includes the WbcO protein from Yersinia enterocolitica and the WbpL protein from Pseudomonas aeruginosa. These transferases initiate LPS O-antigen biosynthesis. Similar to other GlcNAc/MurNAc-1-P transferase family members, WbpL is a highly hydrophobic protein possessing 11 predicted transmembrane segments.