FIG. 2.

Identification of heat-induced rpoH transcripts by S1 mapping. The transcription start site was determined with 10 mg of RNA extracted from non-heat-shocked (−) and heat-shocked (+) cells using rpoH DNA probe fluorescently labeled at the 5′ end. Wild-type ([WT]) cells of A. tumefaciens GV3101 were grown in complete medium at 25°C and heat shocked (shifted to 37°C for 10 min). DNA sequence ladders labeled at the same 5′ end and produced by the Sanger method are shown to the right. The positions of transcription start site and undigested probe are indicated by the closed and open arrows, respectively. The nucleotide sequence of the putative promoter region is shown; the −35 and −10 conserved sequences are underlined, and the start site is circled.