FIG. 3.

Western blot analysis of DnaK and GroEL proteins after heat shock. Synechococcus cells were grown at 30°C and shifted to 45°C at the logarithmic phase (OD₇₀₀ of 0.5). Crude extracts were prepared from cultures at the indicated times after temperature upshift, and samples (30 μg of protein for DnaK and 10 μg of protein for GroEL) were analyzed by Western blotting using antiserum specific to each DnaK protein or anti-B. subtilis GroEL antiserum as described in Materials and Methods.