FIG. 1.

(A) Determination of the transcription initiation site of the ctsR gene by primer extension analysis. Total RNA was extracted from O. oeni cells harvested in the exponential phase before (lane 1) or after (lane 2) a 30-min shift to 42°C. Primer extension products corresponding to the ctsR gene are shown alongside DNA-sequencing reaction products (lanes T, G, C, and A). The corresponding nucleotide sequence is shown on the left. The transcriptional start site is indicated by an asterisk, the −10 sequence is boxed, and arrows indicate the likely CtsR operator sites. (B) Organization of the ctsR-clpC operon and nucleotide sequence of the ctsR promoter region. The putative −10 and −35 sequences are underlined and boldface, arrows indicate the likely CtsR operator sites, and the initiation codon (ATG) is in boldface.