Fig. 5.

Effects of heat shock on levels of pB-derived transcripts in E. coli wild-type (WT) bacteria and the rpoD800 (rpoD) mutant. Bacteria were cultured to A ₅₇₅ of 0.4 (exponential phase) and then one half of the culture was transferred to 45°C (+) while the second half remained at 37°C (−). Following further cultivation for 15 min, RNA was isolated and primer extension experiments were performed as described in “Materials and methods”. The position of the products of primer extension reactions, corresponding to transcripts originating from the pB promoter, is shown