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)

It was shown previously that E. coli RNA-polymerase (EC 2.7.7.6) selectively binds certain fractions of penta- or hexaribonucleotides random mixtures (Knorre V. L., Vasilenko S. V., Salganik R. I., FEBS Lett., 30, 229, 1973). The data obtained demonstrate that such oligoribonucleotides compete with DNA for the RNA polymerase active centre and inhibit DNA dependent RNA synthesis catalyzed by the enzyme. These properties are absent in tri- and tetraribonucleotides which cannot be bound by RNA polymerase. The inhibitory action of the pentaribonucleotides was higher when they had been added prior to DNA to the mixture containing RNA polymerase.
Mol Biol (Mosk)
PMID:[Effect of oligoribonucleotides specifically bound by E. coli RNA-polymerase on DNA-dependent RNA synthesis]. 80 72

Chromosomal non-histone proteins are obtained from nuclei of two types of pigeon erythroid cells: erythroblasts (cells active in RNA synthesis) and erythrocytes (cells with repressed RNA synthesis). They are well soluble in solutions of low ionic strength. Electrophoretic separation of the obtained non-histone proteins in polyacrylamide gels with urea and SDS shows the presence of qualitative differences in the pattern of non-histone proteins of chromatine from erythroblasts and erythrocytes. By electrophoresis in urea some protein bands of non-histone proteins of chromatine from erythroblasts were found which disappear with the aging of cells. At the same time two protein fractions were observed in chromatine from erythrocytes which were absent in that of erythroblasts. Disappearance of some high molecular weight protein fractions from erythrocyte chromatine as compared to erythroblasts was observed by separation of the non-histone proteins in the presence of SDS. These fractions of the non-histone proteins disappearing during aging of cells are well extractable from erythroblast chromatine by 0.35 M NaCl solution. In the in vitro system with E. coli RNA polymerase addition of non-histone proteins of chromatine from erythroblasts to chromatine from erythrocytes increases RNA synthesis 2--3 times. At the same time addition of non-histone proteins from erythrocytes is either without any influence on this process or somewhat inhibiting.
Mol Biol (Mosk)
PMID:[Comparative investigation of the non-histone proteins of chromatin from pigeon erythroblasts and erythrocytes]. 80 71

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 synthesis. At the same time the concentration and the rate of beta'-subunit synthesis is increased. These facts suggest the compensating activation of the synthesis of RNA polymerase subunits that takes place under the conditions of deficiency in one of the subunits. Reversions, as well as more effective suppression of ts22 amber-mutation achieved by streptomycin addition or substitution of su2 by sul result in a rise in the concentration and the rate of beta-subunit formation. This is accompanied by a drop in the concentration and the role of beta'-subunit synthesis. tsX missense motation in the beta'-subunit gene alters the properties of the enzyme increasing at the same time the concentration and the rate of synthesis of both subunits, particularly at nonpermissive temperature. This points to an inversely proportional relationship between the rate of synthesis of RNA polymerase subunits and total intracellular activity of the enzyme. Extra subunits are rapidly degraded in ts22 and tsX mutants.
Mol Biol (Mosk)
PMID:[Synthesis of RNA polymerase subunits in Escherichia coli mutants]. 80 75

A cell free protein synthesizing system, derived from E. coli, is shown to be a quantitiative assay system for messenger RNA extracted from B. subtilis infected with bacteriophage SPO1. DNA-directed protein synthesis in this system is shown to be limited mostly to those proteins whose messages are contained in early RNA. A phage induced enzyme, dCMP deaminase, is shown to be dependent on appearance of a class mRNA made in vivo in response to new initiations of transcription dependent on prior synthesis of phage induced protein. Control of the enzyme synthesized in the cell free system is contrasted with in vivo control, and an estimate of "read-through" by RNA polymerase in vitro is presented.
Mol Gen Genet 1975
PMID:Bacteriophage SPO1 DNA- and RNA-directed protein synthesis in vitro: comparison with in vivo control. 81 Jun 56

Bacillus subtilis strain PB 2427 temperature sensitive in the synthesis of RNA during spore germination and outgrowth has been characterized to some extent. At non permissive temperature (46 degrees C) strain PB 2427 synthesizes stable and unstable RNA for 50 min from the beginning of germination and then stops. Most of the stable RNA is degraded to shorter molecules but can be identified as ribosomal RNA by hybridization-competition experiments. At non permissive temperature, in the presence of chloramphenicol, synthesis of RNA proceeds, though at a reduced rate, for at least 90 min. By hybridization-competition experiments it can also be shown that the RNA synthesized at 46 degrees C in the presence of chloramphenicol includes transcripts that are absent, from the RNA synthesized at 46 degrees C in the absence of drug. The RNA polymerase (holo and core) purified from vegatative cells of the mutant strain does not appear to have a greater heat-lability as compared with the enzyme purified from the parental strain. At non permissive temperature only six polypeptide chains with MW ranging from 47,000 to 78,000 daltons are synthesized by the germinating spores of the mutant.
Mol Gen Genet 1976 Oct 18
PMID:Synthesis of RNA and protein in a mutant of Bacillus subtilis temperature sensitive during spore germination. 82 46

A rapid method suitable for purifying large amounts of mitochondria from rat liver using isopycnic zonal centrifugation is described. The RNA polymerase isolated from the purified mitochrondria was found associated with one peak when resolved by DEAE Sephadex chromatography. The enzyme was next fractionated on a phosphocellulose column followed by glycerol gradient centrifugation. A 600-fold purification was achieved when the enzyme was finally filtered through agarose gel. This final enzyme fraction consisted of one polypeptide chain as shown by polyacrylamide gel electrophoresis profiles. The enzyme has a greater preference for poly [d(A-T)] templates than for rat liver mitochondrial DNA. Inhibition of the enzyme activity required high concentrations of the inhibitors. The resistance of the enzyme to alpha-amanitin indicated that there was no contamination from nuclear RNA polymerase II. The conclusion is drawn that the mitochondrial RAN polymerase activity is associated with a single polypeptide.
Mol Cell Biochem 1976 Dec 10
PMID:Some properties of rat liver mitochondrial RNA polymerase. 100 1

When cytoplasmic protein synthesis is inhibited by cycloheximide (CHI) in vivo synthesis of water-soluble mitochondrial proteins and of mitochondrial RNA is decreased. These changes measured in isolated rat liver mitochondria are similar to those observed in vivo and correlate with the changes the synthesis of water-soluble proteins in mitochondria. When the cytoplasmic fraction (30,000 g-supernatant) had been added to the mitochondria showing decreased RNA synthesis, the RNA synthesis increased to the control level (the incubation conditions were favourable for the protein transport from microsomes to mitochondria). RNA synthesis in mitochondria was not stimulated by cytoplasmic fractions from the CHI-pretreated rats. After prolonged dialysis these fraction stimulated RNA synthesis even to a greater extent than cytoplasmic fractions from the untreated animals. Mitochondrial RNA polymerase activity (measured in mitochondrial extracts supplemented with exogenous DNA) was higher in extracts of mitochondria from livers of normal rats than in extracts of mitochondria from livers of animals injected with CHI.
Mol Biol (Mosk)
PMID:[RNA biosynthesis in mitochondria under conditions of prolonged inhibition of protein biosynthesis in rat liver cytoplasm]. 105 82

The transducing phage lambdarifd18 isolated by Kirschbaum and Konrad [(1973 J. Bacteriol. 116, 517-526] was found to carry structural genes for several 50S ribosomal proteins and 16S and 23S rRNA. It has previously been demonstrated [Kirschbaum & Scaife (1974) Mol. Gen. Genet. 132, 193-201] that this phage carries genes for the DNA-dependent RNA polymerase (nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6) subunits beta and beta'. Thus, the region of the E. coli chromosome carried by lambdarifd18 contains a cluster of genes essential for transcription and translation.
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PMID:Cluster of genes in Escherichia coli for ribosomal proteins, ribosomal RNA, and RNA polymerase subunits. 110 Dec 64

An unlinked regulatory mutation hisT1504, causes an approximate 11-fold derepression of the histidine (his) operon and a linked constitutive mutation hisO1242 causes an approximate 15-fold derepression. In this study we demonstrate that hisT1504 provokes a significant increase in the UV-induced reversion frequency of his ochre and frameshift mutations. Analysis of revertants derived from frameshift mutants show that this increment in derepressed strains compared to the repressed strains is due to better growth of suppressed revertants by weak frameshift suppressors. The frequency of revertants suppressed by strong frameshift suppressors appears to be the same in repressed and derepressed strains. In contrast, intragenic revertants appear at two-fold decreased frequency in derepressed strains carrying either of the histidine constitutive mutations, hisT1504 or hisO1242. A possible competition is indicated between frequently transcribing RNA polymerase and error-promoting recombinational repair within the histidine operon.
Mol Gen Genet 1975
PMID:UV-induced reversion patterns of constitutive and repressed Salmonella histidine auxotrophs. 110 13

The RNA polymerase inhibitor, lomofungin has been used to determine the half life of specific synthetic capacities (invertase and alpha-glucosidase) as well as that for gross protein synthesis. In both cases the studies conclude that cognate messenger RNAs decay with a half life of approximately 20 minutes. This antibiotic has been used to determine the half life of allophanate hydrolase specific synthetic capacity. We find that it decays with a half life of about three minutes; a value that agrees with the decay rates of allophanate hydrolase synthetic capacity following removal of inducer. These observations argue that mRNA may be metabolized by two separate routes in Saccharomyces.
Mol Gen Genet 1975
PMID:Lomofungin inhibition of allophanate hydrolase synthesis in Saccharomyces cerevisiae. 110 15


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