FIG 6.
N-Hydroxybenzimidazoles specifically inhibit the DNA-binding activity of AraC family regulators. ExsAVp-CTD (A) and Vfr (B) were incubated with DMSO (2.5%) or the indicated N-hydroxybenzimidazole (125 μM) for 5 min prior to addition of radiolabeled specific (PexsC or PregA) and nonspecific (algD) probes (0.05 nM each). Binding reactions were allowed to proceed for 15 min at 25°C and then analyzed by native polyacrylamide gel electrophoresis and phosphorimaging. The positions of unshifted probes and shifted protein-DNA complexes are indicated. Quantitation of the percent shift normalized to DMSO-treated ExsAVp-CTD (100%) is indicated. Statistical differences were determined by comparison to DMSO treatment. *, P < 0.01.