Fig. 2

ArcA directly represses flrA expression. a. The EMSA between phosphorylated ArcA protein and the flrA promoter. The concentration of phosphorylated ArcA protein increased gradually (0 to 2.4 μM), and the amount of promoter DNA used in each reaction was 50 ng. 4.5S RNA served as the negative control. b. mRNA levels of flrA in the WT,,ΔarcA mutant strain and arcA complementary strain ΔarcA::ParcA in aerobic conditions. *, p < 0.05; **, p < 0.01; ***, p < 0.001; NS, no significance, p > 0.05. c. Expression of flrA-lux in WT strain and ΔarcA mutant strain. CPS (counts per second) values represent relative promoter-lux activities. All experiments were independently repeated at least three times. Values represent means ± SEM