Polyribitol Phosphate Synthetase of Staphylococcus aureus

The particle-bound polyribitol phosphate synthetase of Staphylococcus aureus catalyzes the synthesis of polyribitol phosphate from cytidine diphosphate ribitol. One phosphate residue and ribitol from the substrate are transferred simultaneously to some endogenous acceptor (the nature of which is unknown) with stoichiometric formation of CMP as the second product of the reaction. The reaction is thus strictly analogous to the reactions of cytidine nucleotides in phospholipid synthesis. In the presence of uridine diphosphate acetylglucosamine, the transferase also present in these particles catalyzes a glycosylation of the growing ribitol phosphate polymer which is highly efficient when compared to the transfer which occurs when polyribitol phosphate is added exogenously as acceptor. The implications of these findings for the biosynthesis of teichoic acid are discussed.