title: Polypeptides containing highly conserved regions of transcription initiation factor sigma 70 exhibit specificity of binding to promoter DNA.
abstract: The sigma 70 subunit of E. coli RNA polymerase is required for sequence-specific recognition of promoter DNA. Genetic studies and sequence analysis have indicated that sigma 70 contains two specific DNA-binding domains that recognize the two conserved portions of the prokaryotic promoter. However, intact sigma 70 does not bind to DNA. Using C-terminal and internal polypeptides of sigma 70, carrying one or both putative DNA-binding domains, we demonstrate that sigma 70 does contain two DNA-binding domains, but that N-terminal sequences inhibit the ability of intact sigma 70 to bind to DNA. Thus, we propose that sigma 70 is a sequence-specific DNA-binding protein that normally functions through an allosteric interaction with the core subunits of RNA polymerase.
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison 53706.
authors.forename: A J
authors.initials: AJ
authors.lastname: Dombroski
authors.forename: W A
authors.initials: WA
authors.lastname: Walter
authors.forename: M T
authors.initials: MT
authors.lastname: Record
authors.forename: D A
authors.initials: DA
authors.lastname: Siegele
authors.forename: C A
authors.initials: CA
authors.lastname: Gross
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D004269:DNA, Bacterial / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D005978:Glutathione / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D010455:Peptides / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012808:Sigma Factor / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; D005982:Glutathione Transferase; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases; D005978:Glutathione