Figure 4. The arcA (blue), crp (red), and etrA (green) promoter activities in mutant strains under either aerobic (A, B) or anaerobic conditions (C, D).

Promoter activities were determined by β-galactosidase activity measurements. Both absolute (A, C) and relative (B, D) activities are shown (refer the text for details). In all panels, W, MR-1; A, ΔarcA; C, Δcrp; E, ΔetrA; AC, ΔarcAΔcrp; AE, ΔarcAΔetrA; CE, ΔcrpΔetrA; T, ΔarcAΔcrpΔetrA.