title: [Localization of a histidine residue in the binding site for the initiating substrate of E. coli RNA-polymerase].
abstract: E. coli RNA polymerase was selectively labelled in the presence of promoters at a histidine residue of the beta-subunit by treatment with GDP beta-imidazolide and then with [alpha-32P]UTP (or [alpha-33P]UTP). Partial cyanogen bromide cleavage of the labelled polypeptide afforded a series of "single-hit" labelled peptides, the electrophoretic pattern of which suggested that the labelling site was His1237. This conclusion was confirmed by a similar pattern obtained with products of the cyanogen bromide cleavage of a radioactive peptide obtained by the limited trypsinolysis (C-terminal peptide consisting of 423 amino acid residues). Interpretation of our earlier results in favour of His1116 as the labelling point (Dokl. Acad. nauk SSSR, 1985, v. 281, p. 723) was incorrect due to the electrophoretic "compression" of three labelled peptide bands.
authors.forename: M A
authors.initials: MA
authors.lastname: Grachev
authors.forename: E A
authors.initials: EA
authors.lastname: Lukhtanov
authors.forename: A A
authors.initials: AA
authors.lastname: Mustaev
authors.forename: M N
authors.initials: MN
authors.lastname: Abdukaiumov
authors.forename: I V
authors.initials: IV
authors.lastname: Rabinov
mesh_terms: D000595:Amino Acid Sequence; D002736:Chloroplasts / Q000201:enzymology; D003488:Cyanogen Bromide; D012321:DNA-Directed RNA Polymerases / Q000032:analysis*; D004926:Escherichia coli / Q000201:enzymology*; D006639:Histidine / Q000032:analysis*; D010442:Peptide Chain Initiation, Translational; D010947:Plants, Toxic; D013379:Substrate Specificity; D014026:Nicotiana / Q000201:enzymology
chemical_list: D006639:Histidine; D012321:DNA-Directed RNA Polymerases; D003488:Cyanogen Bromide
vernacular_title: Lokalizatsiia ostatka gistidina v oblasti sviazyvaniia initsiiruiushchego substrata RNK-polimerazy E. coli.