Fig. 4

ArcA directly represses cytR expression. a. The EMSA between phosphorylated ArcA protein and the cytR promoter. The concentration of phosphorylated ArcA protein increased gradually (0 to 6 μM), and the amount of promoter DNA used in each reaction was 50 ng. b. mRNA levels of cytR in the WT, ΔarcA mutant strain and the complementary strain ΔarcA::ParcA in aerobic condition. *, p < 0.05; **, p < 0.01; ***, p < 0.001; NS, no significance, p > 0.05. c. mRNA levels of cytR in the WT, ΔarcA mutant strain and the complementary strain ΔarcA::ParcA in anaerobic condition. *, p < 0.05; **, p < 0.01; ***, p < 0.001; NS, no significance, p > 0.05. d. Expression of cytR-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, and the data shown represent comparable results. Values represent means ± SEM