FIG. 2.

Primer extension analysis of groESL transcripts synthesized in E. coli A7448. Reverse transcripts were obtained with 15 μg of total RNA isolated from the strain complemented with B. japonicum rpoH₁ (lane 1), rpoH₂ (lane 2), or rpoH₃ (lane 3) or E. coli rpoH (lane E) and 30 μg of RNA from the same strain transformed with pUC18 (lane −). Oligonucleotide Sig123 was used as the primer for the primer extension and corresponding sequencing reactions (lanes T, C, G, and A). The transcription start site used by the ς³²-like proteins is indicated by a solid arrow; the open arrow marks the transcript initiated at the ς⁷⁰-dependent promoter.