Structure and biosynthesis of teichoic acids in the cell walls of Staphylococcus xylosus DSM 20266.

The simultaneous occurrence of a N-acetylglucosaminyl poly(ribitolphosphate) (beta-GlcNAc) and a N-acetylglucosaminyl poly(glycerolphosphate) (alpha-GlcNAc) in the cell walls of Staphylococcus xylosus DSM 20266 was demonstrated by different experimental lines: (1) Fractionation of extracted cell wall teichoic acid on DEAE-cellulose, (2) investigation of the composition of cell walls in the growth cycle, (3) in vitro biosynthesis using crude membranes as the source of enzyme. The polymerization of these polymers starts from CDP-ribitol and CDP-glycerol, respectively. In the presence of UDP-N-acetylglucosamine both polymers are substituted with N-acetylglucosamine at a level and with the identical anomeric configuration found in the native cell wall teichoic acids. The in vitro biosynthesis of poly(glycerolphosphate) was unique in that it was highly stimulated by UDP-N-acetylglucosamine and to a lower extent by other UDP-activated sugars. Kinetic studies have provided evidence that this stimulation is due to an increase of Vmax while Km is unchanged. Competition experiments have indicated that poly(ribitolphosphate) and poly(glycerolphosphate) were synthesized in the in vitro system in a close spatial relationship.