FIG. 3.

Results of gel shift experiment showing the effects of increasing concentrations of MarA on initiation complex (RD) formation at the rob promoter when RNAP was added before MarA. The 37°C assay was used, except that RNAP was added 10 min before MarA at 4°C; after the addition of MarA, the usual 10-min incubation at 4°C was performed before placing the samples at 37°C. The rob DNA concentration was 10 nM. Band labeling is as described for Fig. 2.