The influence of mutations in structural genes of beta and beta subunits of RNA polymerase upon the synthesis of these subunits in E. coli cells have been investigated. An amber-mutation ts22 in the beta subunit gene decreases the intracellular concentration of this subunit and the rate of its synth
DNA Supercoiling and transcription in Escherichia coli: Influence of RNA polymerase mutations
β Scribed by Mirkin, S. M. ;Bogdanova, E. S. ;Gorlenko, Zh. M. ;Gragerov, A. I. ;Larionov, O. A.
- Publisher
- Springer
- Year
- 1979
- Tongue
- English
- Weight
- 580 KB
- Volume
- 177
- Category
- Article
- ISSN
- 0026-8925
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β¦ Synopsis
Coumermycin A1, a specific inhibitor of DNA gyrase, differentially changes the spectrum of proteins synthesized in wild type E. coli cells but has no effect on the protein spectrum in mutant cells with coumermycin-resistant DNA gyrase. The rpoB265 mutation affecting RNA polymerase decreases the coumermycin A1-sensitivity of bacteria while the rpoC3 mutation increases it. The interaction of wild type and mutant RpoB265 RNA polymerases with ColEl plasmid DNA in vitro is differently affected by DNA supercoiling. No such differences are observed in the case of RpoC3 RNA polymerase. The results suggest that template supercoiling may have a substantial effect on transcription in vivo, an effect which, in some cases, depends on the properties of RNA polymerase.
π SIMILAR VOLUMES
Five recombinant plasmids, pBK2646, pBK611, pRC3, pRC4 and pRC5, carrying rpoB rifampicin-resistant RNA-polymerase genes were obtained. The sequence analysis of these plasmids revealed certain structural changes in the rpoB gene which specify corresponding alterations in the beta-subunit of RNA poly
We studied the rate of synthesis of beta-and beta'-subunits of DNA-dependent RNA polymerase and the rate of beta-polypeptide mRNA synthesis in rifampicin-treated bacteria. The chosen antibiotic doses did not significantly inhibit the total RNA and protein synthesis in rifampicin-sensitive bacteria.
Amber mutants of Escherichia coli K-12 affected in the structural gene (rpoD) for th a subunit ofRNA polymerase have been obtained from a strain harboring a temperature-sensitive amber suppressor (supF-Ts6) which is active only at low temperatures. These mutants grow normally at low temperature (30