Figure 2.

C protein cross-talk in the context of TF effects on the racR-ydaST operon. The in vivo effect of the C protein and other TFs on expression of racR (A) and ydaS expression (B). In this experimental system, the E. coli K-12 Δrac strain cells contained two compatible plasmids: one with racR or ydaS promoter fused in the same open reading frame with the lacZ reporter gene; the second plasmid delivered a wild-type or mutated selected TF under the inducible P_araBAD promoter. TF transcriptional profiles were measured as LacZ specific activity (Miller units), at increasing TF concentrations from nearly 0 (in glucose) to the highest concentration (in 0.1% arabinose). The TFs are represented as follows: C regulator (circles – WT dark orange, Cmut light orange); YdaS (squares – WT dark green, YdaSmut light green); RacR (diamonds – WT dark blue, RacRmut light blue). The error bars indicate the averages (± SD) of at least three independent measurements. The trend lines are also shown to facilitate visualization of TF effects.