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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The interaction of pyridoxal, pyridoxal-5'-mono-, di- and triphosphate with certain enzymes of polynucleotide synthesis (
DNA-dependent RNA polymerase
, DNA-dependent DNA polymerase I and polynucleotide phosphorylase from Escherichia coli and terminal deoxyribonucleotide transferase from calf thymus) was studied. All compounds tested was found to be reversible and competitive inhibitors of these enzymes. The reduction of the enzyme-inhibitor complex with NaBH4 gives rise to the complete irreversible inhibition of the enzymes under study. The comparison of the inhibition constants for pyridoxal and its phosphorylated derivatives with those for mono-, di- and triphosphates of nucleosides was carried out for the enzymes. The results obtained suggest that the modified epsilon-amino-group of lysine residue should be localized at the catalytic site in the vicinity of the pyrophosphate binding area of an enzyme.
Mol
Biol (Mosk)
PMID:[Interaction of oligophosphates of pyridoxal with certain enzymes of polynucleotide synthesis]. 38 98
2,6-diaminpurine (DAP) selectively inhibited mitochondrial protein synthesis in yeast cells with concomitant failure of cells to grow in non-fermentable (yeast extract, glycerol) medium. The selectivity was pronounced in all strains tested (15) nearly all of which were able to grow in yeast extract, glucose medium containing 5 mg/ml DAP (maximum solubility) whereas growth was arrested in all strains at 250-500 microgram/ml DAP in the glycerol medium. The inhibition was reversed by further addition of adenine to the culture medium. RNA synthesis in rat liver mitochondria was depressed by DAP suggesting that the analogue affected
RNA polymerase
activity. There was no evidence of nuclear mutagenicity by DAP but resistance to the antibiotics chloramphenicol and oligomycin was induced by the drug. Genetic evidence, although limited, indicated that the resistance mutations were cytoplasmic. The mitochondrial petite mutation was also induced by DAP but only at comparatively high concentrations. The mutagenic effects were seen only in the glycerol medium.
Mol
Gen Genet 1979 Jun 20
PMID:Mitochondrial activity of 2,6-diaminopurine in Saccharomyces cerevisiae. 38 52
Two hundred strains of Saccharomyces cerevisiae temperature sensitive for RNA synthesis were selected and screened in crude extracts for
DNA-dependent RNA polymerase
activities. One strain was isolated which had only residual in vitro
RNA polymerase
B activity. In normal growth conditions total RNA, poly A+ RNA and protein synthesis were indistinguishable from those of the wild type strain at 23 degrees C and after shift to 37 degrees C. A temperature sensitive phenotype was detected only when rpoB containing strains were grown in adverse conditions. The mutant character showed mendelian segregation and was coexpressed with the wild type character in heterozygous diploids. Residual enzyme activity was characterised in crude extracts using synthetic polymers and natural templates in different ionic conditions.
Mol
Gen Genet 1979 Jun 07
PMID:Isolation and characterisation of a strain of Saccharomyces cerevisiae deficient in in vitro RNA polymerase B(II) activity. 38 33
Through cloning and deletion experiments on ColEl hybrids the rpoB gene (Rifr) was located on a physical restriction map;
RNA polymerase
binding studies showed no binding site within the structural gene. The genetic data and
RNA polymerase
binding studies lead to the conclusion that rp/L and rpoB are dependent upon a common promoter.
Mol
Gen Genet 1979 Jun 07
PMID:Deletions, insertions and rearrangements affecting rpoB gene expression. 38 38
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 antibiotic doses used did not significantly inhibit the total RNA and protein synthesis in rifampicin-sensitive bacteria. For RNA-DNA hybridization experiments a pOD162 plasmid was constructed carrying a fragment of the rpoB gene and no other chromosome DNA regions. It is found that low doses of rifampicin cause an absolute and differential increase in the rate of synthesis of the specific mRNA for the beta-subunit, suggesting a stimulation of the corresponding gene transcription. However the absolute transcription stimulation does not fully correlate with the relative acceleration of beta-mRNA and the corresponding polypeptide synthesis. The stimulating effect of rifampicin on the beta-polypeptide synthesis was demonstrated also in a coupled system of transcription and translation directed by lambda rifd 47 DNA. The possible mechanisms of the rifampicin action are discussed.
Mol
Biol (Mosk)
PMID:[Effect of rifampicin on the synthesis of bacterial RNA polymerase mRNA by means of hybrid plasmids]. 38 90
The sequence of two new IS2 alleles with promoter activity (IS2-43 and IS2-44) is reported. The alleles are identical and are formed by a 17 bp tandem duplication in an AT-rich region of IS2. This created a new
RNA polymerase
binding site. A mutation was found that increased the frequency of formation of these 17 bp duplications but not of another class of duplications, the "mini-insertions". This suggested that the mechanisms of formation of the two classes of duplications are different.
Mol
Gen Genet 1979 Aug
PMID:IS2-43 and IS2-44: new alleles of the insertion sequence IS2 which have promoter activity. 39 Mar 7
DNA-dependent RNA polymerase
has been found to be preferentially released at 43 degrees C from the folded nucleoids of an E. coli dnaAts mutant when compared with the same nucleoids at 30 degrees C or with nucleoids of a dnaA+ strain at either 30 degrees or 43 degrees C. The polypeptides released are identical in molecular weight with those of the beta and beta' constituent polypeptides of the core enzyme of a known E. coli
RNA polymerase
. In addition, these polypeptides are precipitated by specific anti-
RNA polymerase
rabbit IgG. The implications of the interactions of
RNA polymerase
with the dnaA gene product are discussed.
Mol
Gen Genet 1979 Sep
PMID:Temperature dependent release of beta-beta' subunits of DNA dependent RNA polymerase from the folded chromosome of a dnaAts mutant of Escherichia coli. 39 Mar 10
We have analyzed some chemical properties of the sigma subunit of
RNA polymerase
from the sigma mutants: rpoD1 (Gross et al., 1978), rpoD2 (formerly known as alt-1) (Silverstone et al., 1972; Travers et al., 1978), and rpoD800 (Gross et al., 1979). Each of the three mutants is located at about 66 min on the E. coli genetic map and exhibits an alteration in the enzymatic properties of its sigma subunit. The tryptic peptides and isoelectric focusing behavior were analyzed for mutant and wild type sigma. A single, but different altered lysine tryptic peptide was observed for each mutant. No altered arginine tryptic peptides were observed. The rpoD800 mutant sigma showed an altered isoelectric point. These studies provide chemical evidence that the sigma polypeptide in all three mutants is altered and strongly support the conclusion that the mutations are in the structural gene for sigma.
Mol
Gen Genet 1979 Oct 01
PMID:Altered chemical properties in three mutants of E. coli RNA polymerase sigma subunit. 39 26
Synthesis of DNA complementary to the transferred strand of an IncI alpha plasmid has been shown previously to require DNA polymerase III. The possible involvement of the two defined priming proteins of Escherichia coli K12,
RNA polymerase
and primase, in initiating this conjugal DNA synthesis had been examined. Primase was inactivated using temperature-sensitive dnaG3 mutants and
RNA polymerase
was inhibited using rifampicin. When these two proteins were simultaneously inactivated in both parental strains, the average recipient synthesised at least one single-stranded equivalent of R144drd-3 before the rifampicin-treated donors lost the ability to transmit DNA. It is proposed that the product of a plasmid transfer gene is responsible for initiating this DNA synthesis in recipients. The results imply that this protein is supplied by the donors.
Mol
Gen Genet 1979 Oct 01
PMID:A novel priming system for conjugal synthesis of an IncI alpha plasmid in recipients. 39 29
A cold-sensitive mutation in the rpoB gene for the
RNA polymerase
beta subunit increasing the temperature of promoter opening on T2 phage DNA was obtained in Escherichia coli. 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 differentially changed by the mutation. The relative efficiency of transcription of these two templates is also changed. These results suggest a participation of the
RNA polymerase
beta subunit in the interaction with promoters.
Mol
Gen Genet 1979 Oct 02
PMID:A cold-sensitive beta subunit mutant RNA polymerase from Escherichia coli with defects in promoter opening in vitro. 39 44
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