FIG. 7.

Search for altered specificity mutations in region 2 of σ³² protein. BB1556 (DnaK⁻) cells were cotransformed with the pSAKT32 and pQF50KgroE plasmids bearing, respectively, the gene encoding wt σ³² or that with the indicated substitutions in region 2 and the wt groE promoter or that with the indicated substitutions in the −10 promoter element. β-Galactosidase activities were normalized to those of cells with wt RNAP and wt promoter as described in the text. All values are averages of five to six independent experiments, with the error bars representing the standard deviations.