FIG. 10.

In vitro transcription from the ast promoters. Single-round transcription experiments with purified components were performed from a supercoiled template with σ⁵⁴ holoenzyme (A) or σ^S holoenzyme (B) and the indicated additions. The concentrations of CRP dimer used were 0, 200, 400, and 800 nM. The expected ∼420-nucleotide transcript was obtained in both cases.