FIG. 1.

Repression of tagA and tagD transcription by PhoP∼P. (A) Map of the plasmid containing divergently transcribed tagA and tagD promoters. The solid horizontal line represents the promoter sequences. The dashed lines represent pCRII vector sequences. The arrows indicate the gene transcription direction. +1 marks the transcriptional start sites. Restriction sites: B, BamHI; E, EcoRI; M, MunI. (B) Diagram of templates containing tagA and/or tagD promoters. The horizontal lines represent DNA fragments used for templates. The arrows indicate the gene transcription direction. Expected sizes of transcripts from the promoters are indicated in parentheses. (C) In vitro transcription of tagA and tagD promoters. Phosphorylation of PhoP and in vitro transcription reactions were carried out as described in the text. The results of coelectrophoresis of Perfect RNA marker template mix (Novagen, Madison, Wis.) are not shown. P, PhoP; R, PhoR; RNAP, purified B. subtilis RNA polymerase. −, absent; +, present.