FIG. 3.

Determination of the σ specificity of ezrA promoters by in vitro transcription assays. The pKM3 plasmid bearing the DNA sequence encompassing both P1 and P2 promoters upstream of ezrA was used as a template for in vitro transcription. A single RNA polymerase holoenzyme or a mixture of two RNA polymerase holoenzymes, as indicated by + and − signs, was used to identify the σ type of the promoters. The transcripts initiated from P1 and P2 and terminated at the first termination site (T1) of the T1T2 terminators are indicated by P1 and P2 with transcript length (in bases) shown in the right margin.