FIG 1.
HapR is a repressor of Pchb that is degraded by the ClpAP protease. Expression of a Pchb-GFP reporter and HapR protein levels were determined in the indicated mutant strains. The parent strain contained a Pchb-GFP reporter and a Δcbp mutation. A representative Western blot is shown below bars to indicate the protein levels for HapR and RpoA (a loading control) in the corresponding strains. An antibody against LuxR, which has 72% identity and 86% similarity to HapR, is cross-reactive with HapR and so was used to detect HapR protein levels. Fluorescence of cultures was determined on a plate reader from at least six independent biological replicates and is shown as the mean ± standard deviation (SD). Statistical comparisons were made by one-way ANOVA with Tukey’s posttest. NS, not significant. ***, P < 0.001.