Heat-shock induction of RNA polymerase sigma-32 synthesis in Escherichia coli: transcriptional control and a multiple promoter system.
Transcriptional start sites of the rpoH gene which codes for a minor sigma factor (sigma 32) of Escherichia coli RNA polymerase were determined. The rpoH gene is transcribed, both in vivo and in vitro, from two major (P1 and P2) and one minor (P2*) promoters. In vitro synthesis of the rpoH mRNAs is dependent on the major species of RNA polymerase holoenzyme (E sigma 70) but not on the minor one (E sigma 32). S1 nuclease analysis of the in vivo RNA showed that the level of rpoH transcript from the downstream P2 promoter increases rapidly when E. coli cells are transferred from 30 degrees C to 42 degrees C, while the transcript from the upstream P1 promoter remains at a constant level. Under these conditions, the metabolic stabilities of rpoH mRNAs are virtually unaffected, suggesting that the synthesis of rpoH mRNA from the P2 promoter is specifically enhanced upon heat-shock.
Fujita
N
N
Department of Molecular Genetics, National Institute of Genetics, Shizuoka, Japan.
Ishihama
A
A
D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis* / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012808:Sigma Factor / Q000096:biosynthesis* / Q000235:genetics; D014157:Transcription Factors / Q000096:biosynthesis*; D014158:Transcription, Genetic
D004269:DNA, Bacterial; D006360:Heat-Shock Proteins; D012808:Sigma Factor; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases