ROLE OF PHOP-SIMILAR-TO-P IN TRANSCRIPTIONAL REGULATION OF GENES INVOLVED IN CELL-WALL ANIONIC POLYMER BIOSYNTHESIS IN BACILLUS-SUBTILIS

tagA, tagD, and tuaA operons are responsible for the synthesis of cell wall anionic polymer, teichoic acid, and teichuronic acid, respective ly, in Bacillus subtilis. Under phosphate starvation conditions, teich uronic acid is synthesized while teichoic acid synthesis is inhibited. Expression of these genes is controlled by PhoP-PhoR, a two-component system. It has been proposed that PhoP similar to P plays a key role in the activation of tuaA and the repression of tagA and tagD. In this study, we demonstrated the role of PhoP similar to P in the switch pr ocess from teichoic acid synthesis to teichuronic acid synthesis, by u sing an in vitro transcription system. The results indicate that PhoP similar to P is sufficient to repress the transcription of the tagA an d tagD promoters and also to activate the transcription of the tuaA pr omoter.