FIG. 1.

ToxT-dependent activation of tcpA-lacZ promoter deletions in E. coli. (A) Strains with no ToxT (shaded bars) or strains with the ToxT-expressing plasmid pTSS-5 (solid bars) were grown overnight in LB medium (pH 6.5) at 30°C. Promoter deletions are carried on plasmid pRS415. The values are averages for at least two independent experiments. (B) tcpA-lacZ deletion series. Most promoter deletions are within a promoter fragment that extends to position +2 relative to the start of transcription; the only exception is the −63 deletion, which extends to +72. The level of activation in the presence of ToxT is indicated for each deletion.