title: Specific contacts between the bacteriophage T3, T7, and SP6 RNA polymerases and their promoters.
abstract: The specificity and structural simplicity of the bacteriophage T3, T7, and SP6 RNA polymerases make these enzymes particularly well suited for studies of polymerase-promoter interactions. To understand the initial recognition process between the enzyme and its promoters, DNA fragments that carry phage promoters were chemically modified by three different methods: base methylation, phosphate ethylation, and base removal. The positions at which these modifications prevented or enhanced binding by the RNA polymerases were then determined. The results indicate that specific contacts within the major groove of the promoter between positions-5 and -12 are important for phage polymerase binding. Removal of individual bases from either strand of the initiation region (-5 to +3) resulted in enhanced binding of the polymerase, suggesting that disruption of the helix in this region may play a role in stabilization of the polymerase-promoter complexes.
authors.affiliation: Department of Microbiology and Immunology, Morse Institute for Molecular Genetics, State University of New York Health Science Center, Brooklyn 11203-2098.
authors.forename: E D
authors.initials: ED
authors.lastname: Jorgensen
authors.forename: R K
authors.initials: RK
authors.lastname: Durbin
authors.forename: S S
authors.initials: SS
authors.lastname: Risman
authors.forename: W T
authors.initials: WT
authors.lastname: McAllister
mesh_terms: D001483:Base Sequence; D003090:Coliphages / Q000201:enzymology / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D008745:Methylation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012689:Sequence Homology, Nucleic Acid; D013604:T-Phages / Q000201:enzymology / Q000235:genetics*
chemical_list: D012321:DNA-Directed RNA Polymerases