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)

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.
Mol Gen Genet 1979
PMID:DNA supercoiling and transcription in Escherichia coli: influence of RNA polymerase mutations. 23 26

The RNA-dependent RNA polymerase induced in BHK 21 cells by infection with foot-and-mouth disease virus has been isolated from the replication complex. It contains a major, virus-coded protein with mol. wt. 56 000 which appears from serological studies and tryptic peptide mapping to be the same as the virus infection associated (VIA) antigen and the protein P56 found in cells infected with the virus. Other virus coded proteins and a host cell protein were present in the partially purified replication complex but were removed by digestion with ribonuclease T1, leaving only the major virus coded protein. The tryptic peptide maps of the VIA antigen of the seven serotypes of the virus were similar, suggesting a high level of conservation in that region of the genome coding for the RNA polymerase of each type.
J Gen Virol 1979 Nov
PMID:Purification and identification of the RNA-dependent RNA polymerase of foot-and-mouth disease virus. 23 34

The growth rate of Saccharomyces cerevisiae was increased by adding a mixture of amino acids to cultures containing proline as the sole nitrogen source. The transition from balanced growth in the basal medium (doubling time 4 h) to balanced growth in the enriched medium (doubling time 2 h) took about 2-5 h. The rate of RNA accumulation increased soon after the enrichment to almost its final value. This increase began after a short lag of 10 to 15 min, therefore synthesis of new RNA polymerase molecules may be required before stable RNA production can increase. The different stable RNA species were not stimulated at different times after the enrichment, but all increased continuosly throughout the transition. The rRNA species accumulated in a co-ordinate fashion at a rate faster than the rate of tRNA accumulation.
J Gen Microbiol 1977 Jan
PMID:Synthesis of ribosomal and transfer ribonucleic acids in yeast during a nutritional shift-up. 31 99

Synthesis of RNA polymerase subunits and of transcription termination factor p was studied after thermoinduction of prophage lambdac1857 located at several unusual sites on the chromosome of Escherichia coli. When a lysogen carrying the prophage at the bfe gene was induced at 42 degrees C, the rate of synthesis of core polymerase subunits (alpha, beta and beta') rapidly decreased, followed by a marked increase after about 10 min. The latter increase was observed specifically in the "bfe lysogen" and not in any of the other lysogens tested. Similarly, the rate of synthesis of p factor increased appreciably in the induced ilv lysogen carrying the prophage at the ilv gene, and possibly in the bfe lysogen as well, but not in other lysogens examined. Taken together with other evidence, these results suggest that the enhanced syntheses of beta and beta' subunits of RNA polymerase and of p factor observerd represent "escape synthesis", resulting from the close linkage of the prophage genome to the respective structural genes. In contrast, omega factor synthesis was stimulated upon induction of any of the lysogens used without respect to the site of prophage location, suggesting the involvement of an entirely different mechanism.
Mol Gen Genet 1977 Feb 15
PMID:Escape synthesis of RNA polymerase subunits and termination factor rho following induction of prophage lambda in Escherichia coli. 32 39

An amber fragment of the beta subunit of Escherichia coli RNA polymerase has been recovered from strains carrying the rpoB12 amber mutation, indicating that the B12 mutation resides in the structural gene for the beta subunit. The fragment is readily assayed and can be used to determine the degree of expression of a single rpoB cistron in strains haploid or diploid for this region. These studies confirm that the bacterial mechanism, which can compensate for reduced translation of the beta message, operates by the co-ordinate induction of rpoB and rpoC. Furthermore, I show that rpo control depends upon cistron(s) located on the F' factor, KLF10, whose product(s) can act negatively in trans on rpoBC expression.
Mol Gen Genet 1977 Feb 28
PMID:Identification of an amber fragment of the beta subunit of Escherichia coli RNA polymerase: a yardstick for measuring controls on RNA polymerase subunit synthesis. 32 70

Bacterial ribosomal RNA synthesis was studied in an in vitro system in which the presence of heparin prevented reinitiation of transcription. The number of heparin-resistant binary complexes of RNA-polymerase and E. coli DNA depended strongly on the quality of the template. High-molecular weight DNA was a much superior template than DNA prepared by conventional techniques. Using this high-molecular weight DNA as template the amount of ribosomal RNA synthetized in one round of transcription was found to be 4-5 fold higher than the amount of rDNA present. Controls have shown that the transcription probably started at the proper initiation sites and no significant read-through form distant promoters contributed to this effect. If the binary polymerase-DNA complexes were dissociated in the presence of 0.5 M KC1 prior to transcription all RNA synthesis was strongly reduced but the proportion of rRNA increased in the transcript. However, in this case the amount of rRNA did not exceed the amount of rDNA. We propose that the promoters of the rRNA genes are complex structures, able to store 4-5 molecules of RNA polymerase and of these several polymerase only one is bound in an extremely salt-resistant form.
Mol Gen Genet 1977 Mar 16
PMID:In vitro transcription of the ribosomal RNA genes of E. coli DNA. 32 75

Ribosomal RNA synthesis from three different rRNA cistrons of E. coli, located on different phage DNAs was compared and found to have the same characteristics as regards chain length, salt and temperature dependence and the effect of ppGpp. However, some clear and reproducible quantitative differences between rRNA synthesis from the different templates both in presence and absence of ppGGpp were found. Rifampicin and heparin experiments showed that these differences were located at the initiation sites. We propose that heterogeneity exists in the RNA polymerase binding regions of the rRNA prmoters in E. coli.
Mol Gen Genet 1977 Mar 28
PMID:In vitro transcription of three different ribosomal RNA cistrons of E. coli; heterogeneity of control regions. 32 80

The product of phage P22 gene c1 has two functions: (1) it promotes synthesis of repressor and (2) during the first minutes of infection it retards expression of some lytic genes. We call the second, negative function "c1 retardation". We investigated c1 retardation in a mutant host of Salmonella typhimurium that is resistant to rifampicin and carries an altered RNA polymerase. No c1 retardation of DNA synthesis was detectable in this host after infection with wild-type phages. This elimination of the normally detectable c1 function leads to the conclusion that the mutant RNA polymerase interferes with the expression of c1 gene activity. Wild-type genes form clear plaques on the mutant host. Mutants of P22 called cly were isolated by others. These mutants form turbid plaques on the altered RNA polymerase host. Infections with P22 cly in the mutant host resulted in detectable c1 retardation. The cly mutation therefore restores c1 activity in a host which wild-type c1 is not expressed. Two spontaneous mutants were isolated from the mutant host. These two strains allowed partial expression of c1 retardation, although they remained rifampicin resistant. We interpret our data to indicate that expression of the normal functions of the gene c1 product requires an interaction of that product with the host RNA polymerase.
Mol Gen Genet 1977 Jun 08
PMID:Effect of mutant host RNA polymerase on the bifunctional activities of P22 gene c1. 32 18

The firA200 mutation of E. coli not only renders RNA synthesis thermosensitive but also eliminates the high-level resistance to rifampicin associated with certain mutations in the beta subunit of the RNA polymerase. A priori, the firA gene is likely to code for an essential component of the transcription apparatus. The isolation is reported of transducing phages for the firA gene, constructed in vitro by fusing fragments of the E. coli chromosomes into a lambdoid bacteriophage. Such phages carry at least two essential genes and are able to suppress both the thermosensitivity and abnormal rifampicin sensitivity associated with the firA200 allele. The finding that some, but not all, of the lambdafirA phages have a temperature dependent growth defect is discussed.
Mol Gen Genet 1977 Jul 07
PMID:The firA gene, a locus involved in the expression of rifampicin resistance in Escherichia coli. I. Characterisation of lambdafirA transducing phages constructed in vitro. 33 Oct 78

The cell-free transcription of the argF and argI genes of the arginine biosynthetic regions is described using an S-30 system capable of coupled in vitro transcription-translation. Template DNA isolated from two independently isolated arginine transducing phages was used in this work. Steady state mRNA synthesis was observed which was attributed to RNAase degradation. Regulation of argF mRNA synthesis, directed by the argF gene carried on the specialized transducing phage phi80dargF is effected to the extent of at least 95% by the arginine holorepressor at the transcriptional stage and at least 80% of the regulation of the expression of the argI gene is mediated at the transcriptional stage. Evidence is presented which indicates that the arginine holorepressor prevents RNA polymerase from binding to the arginine promoter and suggests that the operator and promoter sites may overlap.
Mol Gen Genet 1977 Sep 21
PMID:Transcription of the argF and argI genes of the arginine biosynthetic regulon of Escherichia coli K12, performed in vitro. 33 19


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