Analysis of the rpoD gene encoding the principal sigma factor of Pseudomonas putida.

The gene (rpoD) encoding the principal sigma factor of Pseudomonas putida (Pp) was cloned and sequenced. The amino-acid sequence deduced from the nucleotide sequence of rpoD contained sequences with significant similarity to the conserved region of the principal sigma factors. In vivo transcriptional analyses revealed that the Pp rpoD is transcribed as a monocistronic mRNA of 2.1 kb and that the transcription of rpoD is under control of the heat-shock (HS) response. The transcription start point (tsp) of the gene was determined and found to be different depending on either normal growth (at 30 degrees C) or HS (at 42 degrees C) conditions. The possible promoter sequences for the principal (sigma 70) and the HS RNA polymerase of Pseudomonas were located in the upstream region of the tsp.