Figure 2. Regulation of sstE and outC.

The sttE-uidA and outC-uidA fusions of strain A4206 and A1919, respectively, were assayed in the presence of 5 µg/ml of polymyxin or 10 mg/ml Mg²⁺ in the wt, phoP and pmrA backgrounds. Activities are the mean value from at least four separate experiments and are expressed in µmoles of p-nitrophenol produced per minute and per milligram of bacterial dry weight ± standard deviation.