FIG. 2.
(A) Autoradiograph from a primer extension experiment mapping the 5′ end of sigI mRNA. Equal amounts of RNA isolated before (lane 37) and 5 min after (lane 52) heat shock were used as templates for reverse transcription. The corresponding sequence was obtained with the appropriate primer. The DNA sequence illustrated in the central part is shown at the left side. Putative transcriptional start sites are indicated by asterisks and by S1 and S2. (B) Sequence of the upstream region of sigI. Putative transcriptional start sites are marked by asterisks. The start codon is given in bold letters. The putative promoter sequence (−35 and −10 regions) belonging to S1 is shown below the sequence line. Bases representing the ςA consensus sequence are labeled in capital letters. Above the sequence the potential −10 and −35 regions (underlined bases) belonging to the heat-inducible putative transcriptional start site are shown.