FIG 2.

rpoE_S2R is a suppressor of synthetic double mutants in OMP assembly pathway. (A) Null mutations in rseA but not rpoE_S2R increase basal activity of σE based on expression of the rpoH-P3–lacZ reporter. Graphs represent mean β-galactosidase activity ± SEM; n = 3. (B) Chromosomal arabinose-dependent depletion constructs of surA or bamE were combined with null mutations in the degP, skp, or bamB genes. Strain viability was assayed by plating 10-fold serial dilutions of overnight cultures grown in LB with 0.2% arabinose and washed to remove arabinose before plating. rpoE_S2R fully rescued growth of the strains in the absence of arabinose.