Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.6 (RNA polymerase)
34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A phosphoprotein kinase (ATP : protein phosphotransferase, EC 2.7.1.37) from calf thymus nuclei was purified by DEAE-cellulose chromatography, hydroxyapatite, and Sepharose 6B gel filtration. The enzyme is a cyclic AMP-independent protein kinase by the following criteria: (a) the protein kinase did not bind cyclic AMP; (b) no inhibition of activity was obtained with the heat-stable protein kinase inhibitor from rabbit skeletal muscle; (c) the regulatory subunit of cyclic AMP-dependent protein kinase had no effect on activity; and (d) no inhibition was obtained with antibody to cyclic AMP-dependent protein kinase. The nuclear cyclic AMP-independent protein kinase readily phosphorylated protamine on serine and to a lesser extent on threonine. Homologous nucleoplasmic RNA polymerase (EC 2.7.7.6) is a better substrate than arginine-rich histone, phosvitin or casein. Physical characteristics of the enzyme are described.
...
PMID:Purification and properties of a cyclic AMP-independent protein kinase from calf thymus nuclei. 2 35

Rifampin-resistant (Rifr) mutants were isolated spontaneously from Bacillus subtilis strain 168. A fraction of the mutants did not grow on a minimal medium. A high concentration of one of the L-amino acids (glutamic acid, glutamine, arginine, proline, aspartic acid, or asparagine) was required to restore their growth on the medium. Further analysis of one of the mutants (strain RF 161) suggested that the mutant is unable to use ammonia as a nitrogen source and requires amino acids instead. Activity of glutamate synthase was not detected in the crude extract of the mutant. The Rifr mutation was closely located to cysA and the drug resistance was cotransformed with the property of amino acid requirement at 100% frequency. All revertants to prototrophy tested showed the rifampin-sensitive (Rifs) property. The activity of the DNA-dependent RNA polymerase of the mutant was resistant to rifampin. It is concluded that some alteration of RNA polymerase may cause absence of the activity of an enzyme involved in the nitrogen metabolism.
...
PMID:Pleiotropic effect of a rifampin-resistant mutation in Bacillus subtilis. 9 17

A cyclic adenosine 3',5'-monophosphate-dependent histone kinase (ATP: protein phosphotransferase, EC 2.7.1.37) was isolated from pig brain. The enzyme has been purified 1140-fold; it is homogeneous on polyacrylamide gel electrophoresis and gel filtration. The estimated molecular weight of the enzyme is 120 000. Histone kinase dissociates into a catalytic subunit and a regulatory one (molecular weights 40 000 and 90 000, respectively). The catalytic subunit has been obtained in homogeneous state as evidenced by sodium dodecylsulphate-polyacrylamide gel electrophoresis. At all purification steps, enzymatic activity is stimulated 5-fold by cyclic AMP. An apparent Km value for cyclic AMP is about 3.3 - 10- minus 7 M. In the presence of cyclic AMP(5 - 10- minus 6 M), the Km value for ATP and F1 histone were 1.2 - 10- minus five and 3 - 10- minus 5 M, respectively. Optimum pH value for histone kinase is 6.5, its isoelectric point is situated at pH 4.6. The purified enzyme displays high specificity for the lysine-rich and moderately lysine-rich histones F1, F2a2 and F2b. Arginine-rich histones and other known protein substrates for cyclic AMP-dependent protein kinases (casein, Escherichia coli RNA polymerase, etc.) are extremely poor substrates for this enzyme.
...
PMID:A cyclic adenosine 3',5'-monophosphate-dependent histone kinase from pig brain. Purification and some properties of the enzyme. 23 2

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.
...
PMID:Transcription of the argF and argI genes of the arginine biosynthetic regulon of Escherichia coli K12, performed in vitro. 33 19

We have isolated two regulatory mutants altered in the leader region of the Escherichia coli tryptophan (trp) operon. In one mutant, trpL29, the AUG translation start codon for the trip leader peptide is replaced by AUA. The other mutant, trpL75, has a G leads to A change at residue 75, immediately after the UGA translation stop codon for the trp leader peptide. In vivo, trpL29 and trpL75 increase the efficiency of transcription termination at the trp attenuator 3- to 5-fold. trpL29 and trpL75 also fail to respond fully to tryptophan starvation and other conditions that normally relieve transcription termination at the trp attenuator. The trpL29 mutation, which presumably reduces synthesis of the trp leader peptide, is cis dominant. The effect of starvation for a number of the amino acids in the trp leader peptide was determined. Only starvation for tryptophan and arginine, amino acids that occur at residues 10, 11, and 12 of the 14-residue trp leader peptide, elicits relief of transcription termination. Our findings suggest that translation of trp leader RNA is involved in regulation of transcription termination at the attenuator. A model is discussed in which the location of the ribosome synthesizing the leader peptide is communicated to the RNA polymerase transcribing the leader region.
...
PMID:Translational control of transcription termination at the attenuator of the Escherichia coli tryptophan operon. 36 6

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.
...
PMID:Altered chemical properties in three mutants of E. coli RNA polymerase sigma subunit. 39 26

Deoxyribonucleic acid isolated from argA and argECBH transducing phages was utilized to study the in vitro synthesis of argA, argE, and argCBH messenger ribonucleic acid. The specific regulation of these operons by the arginine holorepressor was demonstrated, providing evidence that the majority, if not all, of the control of these operons is exercised at the transcriptional level. Data are presented which indicate that the arginine holorepressor functions by binding to the operator region and concomitantly prevents the binding of ribonucleic acid polymerase to the corresponding promoter region.
...
PMID:In vitro transcription of the Escherichia coli K-12 argA, argE, and argCBH operons. 40 Jul 84

The analysis of tryptic peptides was performed on the unassembled as well as assembled form f alpha subunit of the DNA-dependent RNA polymerase from Escherichia coli. The peptide profiles obtained by Dowex 50 column chromatography of the unassembled alpha subunit prepared from cells, either pulse-labeled or continuously labeled with radioactive lysine or arginine, were essentially identical with those of the alpha subunit from intact RNA polymerase. The results suggest that newly synthesized free alpha subunit is assembled into the polymerase structure without any remarkable modifications. The number of lysine- and arginine-containing peaks were close to the values expected from the amino acid composition of alpha subunit assuming that the two alpha subunits in RNA polymerase core enzyme have identical primary structure.
...
PMID:Peptide analysis of RNA polymerase alpha subunit from Escherichia coli: comparison of free with assembled form. 78 18

Pituitary growth hormone (GH) has considerable potential as an anabolic agent in animal production. For example, pigs treated with GH will grow faster (i.e. deposit protein), require less feed per unit of body weight gain, and will have less carcass fat than untreated animals. Lactating cows will produce more milk with less feed. It is likely, though not completely established, that young cattle will also respond to GH treatments. Most of the information on the mode of action of GH has been obtained with laboratory rather than farm animals. The hormone affects almost all aspects of metabolism although the specific mechanism for these effects is still not understood. Stimulation of protein accretion is reflected by increased nitrogen retention and incorporation of radioactive amino-acids into tissue proteins. An increased rate of protein synthesis is thought to be a result of enhanced ability of ribosomes to translate messenger RNA. GH increases polyamine synthesis by increased ornithine decarboxylase activity; RNA synthesis by increasing RNA polymerase and DNA synthesis by increased DNA polymerase. Cell division is stimulated in several tissues (e.g. muscle and lymphoid tissue). In vivo GH lowers the respiratory quotient indicating an increased oxidation of fatty acids. The numbers of fat cells do not change but the fat cells are reduced in size. The stimulating effects of GH on skeletal tissue, and perhaps other tissues as well, is mediated by the formation of at least three peptides called somatomedins. GH is a protein with a molecular weight of about 22,000 and contains 191 amino-acid residues. The amino-acid sequence varies with the species. GH isolated from one species is not always effective in a different species. Use of GH isolated from pituitaries does not appear to be economically feasible. A chemical synthesis for human GH has been accomplished. However, biological activity equivalent to the native hormone has not been unequivocally established. Synthesis of bovine or porcine GH is feasible but will be expensive. A partial sequence of GH with 39 amino-acid residues has some biological activity. Synthesis of this shorter peptide would be considerably less expensive. Since proteins generally are not active orally, an economic procedure for prolonged parenteral administration would have to be devised. Althernative approaches would be the stimulation of endogeneous production of GH with hypothalmic GH releasing factor. This factor has not been identified but is probably a small peptide. Agents such as arginine, DOPA, and prostaglandins, which are known to stimulate GH release under some conditions, could also be considered. Another approach would be the implantation of sparganum from the spirometra family (a flatworm). This treatment is known to mimic GH effects in the rat. Implantation of a GH producing tumour could also be considered. Clearly these latter suggestions are quite speculative and would present some obvious problems...
...
PMID:Role of growth hormone in improving animal production. 78 72

The effect of estrogen on gene expression in the chick oviduct was investigated. Studies on the effect of the temperature requirement for ribonuclei acid (RNA) chain initiation by Escherichia coli RNA polymerase on deoxyribonucleic acid (DNA), chromatin, and reconstituted chromatin were carried out to better understand the nature of the initiation process. Varying the temperature or ionic strength during preincubations had little effect on the formation of stable preinitiation complexes between RNA polymerase and chromatin. This was in contrast to similar studies performed on native DNA and indicates that initiation sites for RNA synthesis on chromatin are different from those on double-stranded DNA and resemble more closely initiation of RNA synthesis on single-stranded DNA. These observations suggest that the local unwinding of the initiation region which is required for RNA chain initiation on native DNA may not be a prerequisite for RNA initiation on chromatin. Studies on reconstituted chromatin devoid of different classes of chromatin proteins demonstrate that both histone and nonhistone fractions are essential inmaintaining the charcteristics inherent to initiation of RNA synthesis on chrmatin. Removal of moderately lysine-rich histone or arginine-rich histone fractions led to the complete loss of the characteristic ''chromatin type'' initiation pattern for RNA synthesis whereas removing lysine-rich (F1) histone had no effect. Additional studies suggest that initiation sites on chromatin are not located in freely accessible single- or double-stranded regions of DNA.
...
PMID:Effect of estrogen on gene expression in the chick oviduct. Studies on the initiation of RNA synthesis on chromatin in vitro. 78 84


1 2 3 4 5 6 7 8 9 10 Next >>

---