FIG. 3.

Steady accumulation of ClpL after heat shock. (A) Immunoblot analysis of whole-cell lysates of exponentially growing S. pneumoniae CP1200 cells exposed to 42°C. S. pneumoniae cells grown at 30°C to an A₅₅₀ = 0.3 were heat shocked at 42°C for the indicated times. The culture was harvested and resuspended in lysis buffer. The cells were lysed by sonication. Then 10 μg of proteins was separated by SDS-PAGE and reacted with antisera to ClpL, DnaK, and GroEL. In the case of ClpP, 30 μg of proteins was used for SDS-PAGE, followed by immunoblot analysis. (B) Densitometric analysis of relative levels of ClpL, ClpP, DnaK, and GroEL after heat shock, as shown in panel A. The figure shows the standard deviation from three independent experiments.