FIG. 2.

Transcription analysis of the hrcA and grpE genes. Cells were grown at 25°C in complete medium to mid-log phase and exposed to 37°C for 15 min. Samples taken before and after heat shock were used for RNA extraction. ³²P-labeled primers for hrcA (a) or grpE (b) were hybridized with 10 μg of each RNA and subjected to primer extension analysis. The cDNA products were resolved by 6% sequence gels and autoradiographed. Sequence ladders produced by the same respective primers were run as markers, and the positions relative to the initiation codons are indicated. The positions of major signals are marked by boxes. Lanes: 1 and 2, GV3101 (rpoH⁺); 3 and 4, KN501 (ΔrpoH); 5 and 6, GV3101(phrcA-grpE); 7 and 8, KN501(phrcA-grpE). +, present; −, absent.