Visualization of Wall Teichoic Acid Decoration in Bacillus subtilis.

Teichoic acids are important for the maintenance of cell shape and growth in Gram-positive bacteria. Bacillus subtilis produces major and minor forms of wall teichoic acid (WTA) and lipoteichoic acid during vegetative growth. We found that newly synthesized WTA attachment to peptidoglycan occurs in a patch-like manner on the sidewall with the fluorescent labeling compound of the concanavalin A lectin. Similarly, WTA biosynthesis enzymes fused to the epitope tags were localized in similar patch-like patterns on the cylindrical part of the cell, and WTA transporter TagH was frequently colocalized with WTA polymerase TagF, WTA ligase TagT, and actin homolog MreB, respectively. Moreover, we found that the nascent cell wall patches, decorated with the newly glucosylated WTA, were colocalized with TagH and WTA ligase TagV. In the cylindrical part, the newly glucosylated WTA patchily inserted into the bottom of the cell wall layer and finally reached the outermost layer of the cell wall after approximately half an hour. Incorporation of newly glucosylated WTA was arrested with the addition of vancomycin but restored with the removal of the antibiotic. These results are consistent with the prevailing model that WTA precursors are attached to newly synthesized peptidoglycan.