| Abstract: | The stepwise formation and characterization of linkage unit intermediates and their functions in ribitol teichoic acid biosynthesis were studied with membranes obtained from Staphylococcus aureus H and Bacillus subtilis W23. The formation of labeled polymer from CDP-14C]ribitol and CDP-glycerol in each membrane system was markedly stimulated by the addition of N-acetylmannosaminyl(beta 1----4)N-acetylglucosamine (ManNAc-GlcNAc) linked to pyrophosphorylyisoprenol. Whereas incubation of S. aureus membranes with CDP-glycerol and ManNAc-14C]GlcNAc-PP-prenol led to synthesis of (glycerol phosphate) 1-3-ManNAc-14C]GlcNAc-PP-prenol, incubation of B. subtilis membranes with the same substrates yielded (glycerol phosphate)1-2-ManNAc-14C]GlcNAc-PP-prenol. In S. aureus membranes, (glycerol phosphate)2-ManNAc-14C]GlcNAc-PP-prenol as well as (glycerol phosphate)3-ManNAc-14C]GlcNAc-PP-prenol served as an acceptor for ribitol phosphate units, but (glycerol phosphate)-ManNAc-14C]GlcNAc-PP-prenol did not. In B. subtilis W23 membranes, (glycerol phosphate)-ManNAc-14C]GlcNAc-PP-prenol served as a better acceptor for ribitol phosphate units than (glycerol phosphate)2-ManNAc-14C]GlcNAc-PP-prenol. In this membrane system (ribitol phosphate)-(glycerol phosphate)-ManNAc-14C]GlcNAc-PP-prenol was formed from ManNAc-14C]GlcNAc-PP-prenol, CDP-glycerol and CDP-ribitol. The results indicate that (glycerol phosphate)1-3-ManNAc-GlcNAc-PP-prenol and (glycerol phosphate)1-2-ManNac-GlcNAc-PP-prenol are involved in the pathway for the synthesis of wall ribitol teichoic acids in S. aureus H and B. subtilis W23 respectively. |
