Biosynthesis of the unit that links teichoic acid to the bacterial wall: Inhibition by tunicamycin

Abstract

The walls of Gram-positive bacteria contain acidic polysaccharides and teichoic acids that are covalently linked through phosphodiesters to muramic acid residues in the peptidoglycan. It has been shown recently that in St@yZococcus agrees H [ 1 ] and in a mutant strain that lacks N-acetylglucosaminyl substituents on its wall teichoic acid [2] a ‘linkage unit’ that is a trimer of glycerol phosphate is interposed between the phosphate-terminal end of the teichoic acid chain and a muramic acid residue of the peptidoglycan to which it is attached. Evidence for similar linkage units has been found in Micrococcus sp. 2102 and in Bacillus subtilis W32 [J. Coley and E. Tarelli, unpublished work]. None of the bacteria examined contains a glycerol teichoic acid in its wall, and it has been demonstrated that the glycerol membrane teichoic acids are synthesized from phosphatidylglycerol [3,4]. Nevertheless, we have found [5] that membrane preparations from all of them catalyse the synthesis from CDP-glycerol of material containing a glycerol phosphate oligomer. Maximal synthesis of this product requires the addition of UDP-N-acetylglucosamine and the substrate for the synthesis of the backbone of the wall teichoic acid. The product is amphiphilic and appears to consist of the teichoic acid chain linked through the glycerol phosphate oligomer to a lipid acceptor. Bracha and Glaser [6] found that synthesis of the ribitol teichoic acid covalently linked to wall, in a wall-membrane preparation from S. aure’eus H, also required the addition of CDP-glycerol and UDP-N-acetylglucosamine. If therefore appears that teichoic acid attached to linkage unit is synthesized in