Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rifampicin (30 mkg/ml) drastically changes the spectra of proteins synthesized by E. coli cells. The formation of some polypeptides is stimulated while that of others is inhibited. Thus, the earlier reported rifampicin stimulation of the synthesis of RNA polymerase beta and beta'-polypeptides is not an exception, the formation of some other proteins is being also enhanced by the antibiotic. After infection of UV-irradiated cells by lambda rifd47 transducing phage the viral proteins are less inhibited than the bacterial ones encoded by the phage. The spectra of proteins synthesized are also affected by rpoC1 mutation at non-permissive temperature. The obtained data suggest that rifampicin and rpoC1 mutation change the interaction of RNA polymerase with different promoters and/or regulatory factors.
Mol Biol (Mosk)
PMID:[Effect of rifampicin and RNA polymerase changing mutation on the spectrum of proteins synthesized in Escherichia coli cells]. 39 2

A cold-sensitive mutation in Escherichia coli, affecting the beta-subunit of RNA polymerase and causing an increase in the temperature of promoter opening on T2 phage DNA, was obtained. The mutation also affects the stages preceding promoter opening by increasing the dissociation rate of RNA polymerase--DNA closed complexes. The affinity of RNA polymerase to T2- and lambda-DNA is differently changed by the mutation. The relative efficiency of transcription of these two templates is also changed. These results suggest a participation of the beta-subunit of RNA polymerase in the interaction with promoters.
Mol Biol (Mosk)
PMID:[Cold-sensitive mutation in the beta-subunit of Escherichia coli RNA polymerase affecting the opening of promoters]. 39 1

The molecular structure of RNA polymerases from Escherichia coli, Salmonella typhimurium, Salmonella anatum,serratia marcescens, Aerobacter aerogens, Proteus mirabilis and Bacillus subtilis were compared based on:i) inhibition of the enzyme activity by treatment with antibodies against E. coli RNA polymerase subunits;ii) analysis of antibody precipitates by sodium ododecyl sulfatepolyacrylamide gel electrophoresis; and iii) analysis of antibody precipitates by urea-isoelectrofocusing followed by sodium dodecyl sulfate-slab gel electrophoresis in the second dimension. All the bacterial RNA polymerases examined cross-react equally with anti-E. COLI HOLOPOLYMERASE BUT EXHIbit different extents of cross-reaction with antibodies against individual subunits. Except for B. subtilis RNA polymerase, the molecular weight and isoelectric point of the enzyme subunits are close to those of E. coli polymerase. However, minor difference were found at least within the resolution of the techniques employed:S. anatum polymerase has sigma subunit larger than E. coli sigma subunit; P. mirabilis enzyme has sigma subunit larger in size and more acidic in charge, and alpha subunit smaller and more basic than corresponding E. coli subunits. The electrophoretic map of B. subtilis enzyme subunits is completely different from that of E. coli enzyme.
Mol Gen Genet 1977 Jul 20
PMID:Comparative studies of RNA polymerase subunits from various bacteria. 40

Synthesis of malic enzyme was rapidly and markedly stimulated by the addition of triiodothyronine to chick embryo liver cells in culture. Alpha-Amanitin, an inhibitor of DNA-dependent RNA polymerase II, blocked induction. The kinetics of induction and de-induction of malic enzyme synthesis suggested that the most stable event in triiodothyronine induction had a half-life of 18 to 20 h. However, malic enzyme synthesis decayed with a half-life of 2,4 h when transcription was inhibited with alpha-amanitin. Thus a long-lived event in thyroid hormone stimulation of malic enzyme synthesis occurred prior to transcription of a specific messenger RNA (mRNA), presumably malic enzyme mRNA. Malic enzyme synthesis decayed with a half-life of about 2 h when glucagon was added to pre-induced liver cells. The similarity of decay rates after inhibition of transcription with alpha-amanitin or inhibition of malic enzyme synthesis by glucagon suggests that glucagon may inhibit the transcription or processing of a specific mRNA required for malic enzyme synthesis.
Mol Cell Endocrinol 1978 Jun
PMID:Regulation of malic enzyme synthesis by thyroid hormone and glucagon: inhibitor and kinetic experiments. 56 41

Transcriptional complexes formed in vitro with coliphage T5 DNA as template were analyzed by electron microscopy and the number and location of starting sites utilized by E. coli RNA polymerase were determined. Of the 40 promoters characterized in this way, 6 map in the two terminal "pre-early" regions, 29 in the "early" and 5 in the "late" region. The direction of transcription within the different regions determined in this study agrees with earlier findings derived from RNA synthesized in vivo.
Mol Gen Genet 1978 Oct 30
PMID:Electron microscopic analysis of in vitro transcriptional complexes: mapping of promoters of the coliphage T5 genome. 74 95

As an effort to elucidate the control of quality and quantity of the DNA-dependent RNA polymerase in Escherichia coli, the rate of synthesis of the individual subunits was determined during shift-up and -down of nutrients. When the strain B/r grown in a succinate medium was imposed to a shift-up by adding a mixture of glucose and amino acids, rapid rise was observed of the differential rates of the synthesis of alpha, beta and beta' subunits, the constituents of core enzyme, leading to the increase of core polymerase concentration. The differential rates decreased thereafter to the level characteristic of the post-shift rate of cell growth. Compared to the strain B/r, the adaptation was slow in the strain K12 W3350. On the other hand, upon transfer of the strain B/r from a glucose-amino acids medium to a glucose medium lacking amino acids, the differential rate of core polymerase synthesis decreased rapidly and then regained the rate characteristic of the new growth rate. Similar control was also observed on the rate of ribosomal protein synthesis suggesting the coordinate expression of genes for the core polymerase subunits and ribosomal proteins. Thus, the intracellular concentration of RNA polymerase as well as of ribosomes might be one of the most important factors that affect the rate of bacterial growth. The rate of alpha subunit synthesis, however, exhibited little change during the shift-up but a considerable decrease was observed during the shift-down.
Mol Gen Genet 1975 Dec 23
PMID:Biosynthesis of RNA polymerase in Escherichia coli. II. control of RNA polymerase synthesis during nutritional shift up and down. 76 37

Studies on the rate of synthesis of the beta and beta' subunits of RNA polymerase in haploid strains of Escherichia coli K12 containing poorly-suppressed rif degrees am mutations provide conclusive evidence that synthesis of at least these two subunits is regulated.
Mol Gen Genet 1975 Dec 30
PMID:Induction of RNA polymerase synthesis in Escherichia coli. 76 46

E coli RNA polymerase holoenzyme is able to recognize transcription initiation sites on Adenovirus 2 DNA that are functionally indistinguishable from promoters for the enzyme on phage DNAs. The complexes formed between the polymerase and the DNA at these sites can exist in two states-either as I (initiation) complexes, from which rapid RNA chain initiation is not possible, or as RS (rapid starting) "rifampicin resistant" complexes, from which rapid RNA chain initiation can occur. When transcription is limited to that initiated from stable, rifmapicin-resistant pre-initiation complexes, initiation is strictly dependent on the presence of sigma factor; in addition, the frequency of initiation exhibits sigmoidal dependence on the temperature at which pre-initiation complexes are allowed to form, with a transition temperature of 26-28 degrees C. The average half-time for initiation of RNA chains from sites on Ad 2 DNA is shown to be comparable to half-times for initiation of RNA chains from promoters on T7 and lambda DNAs. At saturating levels of enzyme, the half-times are 0.6, 0.9, and 1.6 sec for lambda b2, Ad 2 and T7 DNAs, respectively. The existence of efficient, phage-like promoters for E coli RNA polymerase on Ad 2 DNA suggests to us that such promoters may be closely related functionally and spatially to promoters for mammalian RNA polymerases.
Mol Gen Genet 1976 Jan 16
PMID:I.n vitro transcription of adenovirus 2 DNA. I. Characterization of promoters for E. coli RNA polymerase. 76 51

We estimate that E. coli RNA polymerase is able to form stable, rifampicin-resistant, pre-intiation complexes with Adenovirus 2 DNA at three to six binding sites. The number of RNA chains initiated from such complexes has been determined form the incorporation of gamma-32P-ATP and -GTP at two rifampicin concentrations (7 mug/ml and 24 mug/ml) and after pre-incubation at either 25 or 37 degrees C. The total number of RNA chains initiated ranges from 2.6 per Ad 2 DNA molecule at a rifampicin concentration of 24 mug/ml and pre-incubation temperature of 25 degrees C, to 5.4 per Ad 2 DNA molecule at a rifampicin concentration of 7 mug/ml and pre-incubation temperature of 37 degrees C. Efficient initiation with GTP occurs only after pre-incubation at 37 degrees C whereas initiation with ATP is equally as efficient at either pre-incubation temperature. Promoters for initiation with ATP have been localized to the leftmost 58% of the Ad 2 DNA molecule, defined by the EcoR.RI restriction endonuclease fragment A; promoters for initiation with GTP are located on the remaining 42% of the Ad2 DNA molecule. It is likely that on Adenovirus 2 DNA each RNA chain is initiated from a unique binding site which constitutes a seperate promoter for E. coli RNA polymerase.
Mol Gen Genet 1976 Jan 16
PMID:In vitro transcription of adenovirus 2 DNA. II. Quantification and localization of promoters for E. coli RNA polymerase. 76 52

Temperature-sensitive mutants of Escherichia coli that are unable to grow at high temperature can be obtained among those selected for resistance to streptovaricin or rifampicin at low temperature (Yura et al., 1973). One of these mutants (KY5323) that was supposed to carry a single mutation affecting both rifampicin resistance and temperature sensitivity was further investigated. Using purified RNA polymerase preparations obtained from the mutant and the wild type, it was found that the activity for RNA chain elongation is more sensitive to heat treatment than that for RNA chain initiation or DNA binding, and that the mutant enzyme is significantly more labile than the wild-type enzyme with respect to RNA chain elongation, when heat treatment is carried out at high salt concentration. These results, taken together with those of the enzyme reconstitution experiments, strongly suggest that the beta subunit of the polymerase is directly involved in both RNA chain initiation and elongation reactions. Enzyme reconstitution experiments using isolated subunits derived from the mutant and the wild-type polymerases demonstrate that the alteration of beta subunit is primarily responsible for both rifampicin resistance and thermolability of the mutant enzyme. In addition, the results suggested the apparent alteration of both beta and alpha subunits in this mutant. Extensive transduction experiments provided genetic evidence that are consistent with the view that the strain KY5323 carries a second mutation affecting the beta subunit, beside the primary mutation affecting the beta subunit. The hypothetical beta subunit mutation seems to modify quantitatively the rifampicin resistance caused by the beta subunit mutation.
Mol Gen Genet 1976 Feb 02
PMID:RNA polymerase mutants of Escherichia coli. III. A temperature-sensitive rifampicin-resistant mutant. 76 57


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