Fig. 5.

Effect of substitution K130A in Region 3.0 of σ³² in suppressing promoter mutations at positions −16 and −15. A. Effect of wt and K130A σ³² on promoters with single-base changes at position −16 or −15.

B. Effect of K130A σ³² on groE and grpE promoters with single-base changes at other positions in the promoter.

C. Effect of wt and K130A of σ³² on promoters with double-base changes at positions −16 and −15. β-galactosidase activity driven by each σ³² variant on mutant groE or grpE promoters is shown as a percentage of β-galactosidase activity of each σ³² variant from the wt promoter. Assay strains are as described in Fig. 1A. Below the x-axis, mutation and position indicate the base change at the different promoter positions; promoter indicates the groE or grpE promoter; σ³² indicates the σ³² wt or mutant derivative. All values are averages of at least three independent experiments; error bars indicate one standard deviation.