FIG. 5.

Heat shock-induced expression of clpB, clpC, and clpE from L. lactis. (A to C) Total RNA was extracted from L. lactis MG1363 (wild type) growing exponentially at 30°C (lane 1) or at 5 min (lane 2), 15 min (lane 3), or 25 min (lane 4) after transfer to 43°C. RNA was also extracted from clpE (HI1615; lane 5) or clpC (HI1632; lane 6) mutant cells 15 min after a shift from 30 to 43°C. Ten micrograms each RNA preparation was separated on an agarose gel and transferred to a nylon membrane that was reacted with clpC-specific (A), clpE-specific (B), and clpB-specific (C) probes. (D) The resulting X-ray autoradiograms were quantitated by densitometric scanning. The mRNA synthesized at 43°C was normalized to the amount present at 30°C. White columns; clpB; grey columns, clpC; black columns, clpE.