Interaction of Escherichia coli RNA polymerase holoenzyme containing sigma 32 with heat shock promoters. DNase I footprinting and methylation protection.
The DNase I protection pattern of E sigma 32 was assayed on three heat shock promoters, the E sigma 32 promoter for the groESL operon, P2 of the dnaKJ operon, and rpoD PHS, the E sigma 32 promoter upstream from rpoD. E sigma 32 protected each of these promoters from DNase I digestion from around -60 to around +20. Protection from dimethyl sulfate methylation was assayed at the groE promoter. E sigma 32 binding altered the sensitivity to methylation of bases in the vicinity of both the -10 and -35 regions. The DNase I footprints for the E sigma 32 promoters were very similar to the DNase I footprint of E sigma 70 on the lacUV5 promoter. After analyzing the DNase I footprints by taking into account the contacts predicted to be made by DNase I, it appeared that E sigma 32, like E sigma 70, contacts the DNA primarily on one face of the helix in the -35 region and on both faces in the -10 region.
Cowing
D W
DW
Department of Bacteriology, University of Wisconsin-Madison 53706.
Gross
C A
CA
D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics*; D008745:Methylation; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012808:Sigma Factor / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; D006360:Heat-Shock Proteins; D012808:Sigma Factor; D014157:Transcription Factors; D012321:DNA-Directed RNA Polymerases; D003850:Deoxyribonuclease I