Cell Walls of Teichoic Acid Deficient Mutant of Bacillus subtilis.

The Cbl-1 mutant of Bacillus subtilis 168 WT is the result of a spontaneous mutation presenting a pleiotropic character. In this paper, the results of the morphological and chemical analyses of the cell walls isolated from both strains are compared. When either the whole cells or the isolated cell walls of both strains were fixed with osmium tetroxide, the examination by electron microscopy showed extensive morphological differences in structure due to the partial destruction of the mutant cell walls. The chemical investigations performed on the isolated cell walls revealed surprising differences in chemical structure. In the cell walls of the mutant, teichoic acid was completely missing and was replaced by protein. A major protein-containing fraction accounting for about 50% of the material solubilized by autolysis of the mutant cell walls was isolated. Polyacrylamide gel electrophoresis showed that this fraction was composed mainly of a single protein of high molecular weight When denatured by sodium dodecyl sulfate treatment in the presence of β-mercaptoethanol, the protein yielded by gel electrophoresis two major bands with molecular weights of approximately 105000 and 155000, respectively. The molecular weight of the Cbl-1 cell wall protein determined by high speed sedimentation equilibrium was 255 600. [ABSTRACT FROM AUTHOR]