Fig. 3.

Both MarA and Rob are required to fully repress OmpF expression in the outer membrane during salicylate exposure. Presence or absence of genes is indicated by + and −, respectively. Cells were grown overnight in medium A and subcultured 1:200 in fresh medium A containing 5 mM salicylate. Cultures were grown to mid-logarithmic phase prior to envelope extraction. Envelope fractions were displayed on 10% acrylamide–6 M urea-1% SDS gels and stained with Coomassie R250. Strains used were MG1655 and CR721 to CR728.