FIG. 3.

Effect of disruption of the extended −10 motif on induction of cspA. (A) Western blot analysis of E. coli ΔcspA cells carrying pJJGO2 plasmids with either the wild-type or the mutated cspA promoter region was carried out with anti-CspA antibodies. Cell extracts were prepared from cells grown at 37°C and cells cold shocked at 15°C for 1 h. (B) Abortive transcription initiation using DNA templates containing either wild-type or mutated promoter region of cspA. The reactions were carried out at 37 or 15°C. Reaction products were separated by denaturing PAGE. The position of the synthesized product (CpApA) is indicated by an arrow.