FIG. 6.

Effect of HrcA on the level of GroEL. Cells of C. crescentus NA1000 (hrcA⁺) or LS2293, which presents a disruption of the hrcA gene, were grown to mid-log phase at 30°C or shifted to 42°C for the times (minutes) indicated. Protein extracts were prepared and separated by SDS-polyacrylamide gel electrophoresis. After transfer of the proteins to nitrocellulose membranes, the blots were probed with antibody to GroEL or to DnaK, as described in Materials and Methods. Equal amounts of protein were applied to all lanes, and hrcA⁺ and hrcA samples were loaded on the same gel and processed together. The relative levels of GroEL and DnaK, determined by densitometry scanning of the films, are shown below the blots; hrcA⁺ (○) and hrcA (▪).