title: Streptolydigin-resistant mutants in an evolutionarily conserved region of the beta' subunit of Escherichia coli RNA polymerase.
abstract: Mutations conferring streptolydigin resistance onto Escherichia coli RNA polymerase have been found exclusively in the beta subunit (Heisler, L. M., Suzuki, H., Landick, R., and Gross, C. A. (1993) J. Biol. Chem. 268, 25369-25375). We report here the isolation of a streptolydigin-resistant mutation in the E. coli rpoC gene, encoding the beta' subunit. The mutation is the Phe793-->Ser substitution, which occurred in an evolutionarily conserved segment of the beta' subunit. The homologous segment in the eukaryotic RNA polymerase II largest subunit harbors mutations conferring alpha-amanitin resistance. Both streptolydigin and alpha-amanitin are inhibitors of transcription elongation. Thus, the two antibiotics may inhibit transcription in their respective systems by a similar mechanism, despite their very different chemical nature.
authors.affiliation: Rockefeller University, New York, New York 10021, USA.
authors.forename: K
authors.initials: K
authors.lastname: Severinov
authors.forename: D
authors.initials: D
authors.lastname: Markov
authors.forename: E
authors.initials: E
authors.lastname: Severinova
authors.forename: V
authors.initials: V
authors.lastname: Nikiforov
authors.forename: R
authors.initials: R
authors.lastname: Landick
authors.forename: S A
authors.initials: SA
authors.lastname: Darst
authors.forename: A
authors.initials: A
authors.lastname: Goldfarb
mesh_terms: D000595:Amino Acid Sequence; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005075:Biological Evolution; D017124:Conserved Sequence; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D005798:Genes, Bacterial; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D046911:Macromolecular Substances; C100307:streptolydigin; D012321:DNA-Directed RNA Polymerases