FIG. 5.
Effect of σE overexpression on ompR malT(Con) survival. (A) Growth curves of the ompR malT(Con) mutant (strain AJW3098) transformed with the empty pTrc99a vector (circles) or the vector carrying rpoE (triangles) under nonpermissive conditions. Expression of rpoE was induced with 50 μM IPTG. Values represent the means of triplicates, and error bars indicate standard deviations and are shown only when greater than the size of the symbol. (B) β-Galactosidase activity of the ompR malT(Con) mutant carrying an Φ(rpoHP3-lacZ) promoter fusion transformed with the empty pTrc99a vector (left bar) or the vector expressing rpoE (right bar). Cells were grown under nonpermissive conditions, and expression of rpoE was induced with 50 μM IPTG. Cells were harvested at an OD600 of 1. Values represent the means and standard deviations for triplicates.