Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.21.1 (DNase)
 7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

RNA polymerase was extracted from the Schmidt-Ruppin strain of Rous sarcoma virus (SR-RSV)-induced C3H/He mouse ascites sarcoma cells (SR-C3H). RNA polymerase was separated into RNA polymerases I and II by DEAE-Sephadex chromatography. RNA polymerase I was separated into Ia and Ib fractions by phospho-cellulose chromatography. In SR-C3H cells RNA polymerase Ib was the main component of RNA polymerase I. At 0.05--0.1 M ammonium sulphate RNA polymerase I transcribed native DNA most actively, and RNA polymerase II transcribed denatured DNA most actively. Partial digestion of DNA by DNAase I enhanced RNA synthesis by RNA polymerases I and II. At ionic strength over 0.2 M ammonium sulphate, the initiation reaction of RNA polymerases I and II was inhibited. The initiation complexes of RNA polymerases I and II with native DNA were more stable against high salt concentration than with denatured DNA.
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PMID:Characterization of RNA polymerases from Rous sarcoma virus-induced mouse ascites sarcoma cells. 3 35

DNA synthesis was studied in mouse ascites sarcoma cells using a permeable cell system. The sarcoma was induced by the Schmidt-Ruppin strain of Rous sarcoma virus. The cells were made permeable to nucleoside triphosphates by treatment with a hypotonic buffer containing 10 mM Tris Cl, 4 mM MgCl2, 1 mM EDTA, and 6 mM 2-mercaptoethanol (pH 8.0). DNA-synthetic activity in the permeable cells was highly dependent on four deoxyribonucleoside triphosphates, adenosine triphosphates, Mg2+, and a proper ionic environment. The activity was stimulated about 50% by the addition of an appropriate concentration of cytidine triphosphate, guanosine triphosphate, and uridine triphosphate in an assay mixture containing adenosine triphosphate and four deoxyribonucleoside triphosphates. DNA synthesis was confined to the nucleus and was sensitive to N-ethylmaleimide and DNase. The activity assayed by the permeable cell system correlated closely with the DNA-replicating activity assayed by [3H]deoxythymidine incorporation in intact cells. The close correlation between DNA synthesis in vitro and in vivo was further confirmed in cultured sarcoma cells synchronized with DNA synthesis. Analysis of the DNA synthesized in vitro by alkaline cesium sulfate density gradient centrifugation showed that over half the DNA synthesized in permeable cells was due to elongation of strands initiated in vivo. The permeable cell system appears to be a useful method for examining DNA replication of cells in suspensions.
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PMID:DNA synthesis inpermeable mouse ascites sarcoma cells. 18 30

In addition to the previously described deoxyribonucleic acid (DNA) polymerase, DNA ligase, DNA exonuclease, and DNA endonuclease activities, purified virions of Schmidt-Ruppin strain of Rous sarcoma virus (SRV) have nucleotides and nucleotide kinase, phosphatase, hexokinase, and lactate dehydrogenase activities. The SRV virions have no glucose-6-phosphate dehydrogenase activity. All enzyme activities, but glucose-6-phosphate dehydrogenase and adenosine triphosphatase, were increased by disruption of the virions. The DNA polymerase, DNA ligase, and hexokinase activities had a higher specific activity in purified virion cores. It is suggested that during assembly virions of SRV may pick up cytoplasmic components which bind to virion proteins. The role of these components in viral replication is not known at present.
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PMID:Enzymes and nucleotides in virions of Rous sarcoma virus. 433 49

Beppu, Michiko (University of Tokyo, Tokyo, Japan), and Kei Arima. Decreased permeability as the mechanism of arsenite resistance in Pseudomonas pseudomallei. J. Bacteriol. 88:151-157. 1964.-The mechanism of arsenite resistance of Pseudomonas pseudomallei strain 54, isolated from soil, was studied by use of radioactive arsenite. Arsenite resistance was found to be related to decreased permeation of arsenite into the cells. P. pseudomallei 54 cells can accumulate arsenite, but the organisms grown adaptively in the presence of arsenite accumulate only a small amount of the drug. Arsenite accumulated in the cells can exchange freely with extracellular arsenite. The apparent dissociation constant of the "bacterium-arsenite complex" was calculated as 5.9 x 10(-5)m for the sensitive cells and 6.3 x 10(-4)m for the resistant ones. No significant difference was observed in the arsenite capacity (maximal uptake) of the cells (2 x 10(-3) mmoles per 30 mg of dry cells). The uptake of arsenite by the sensitive cells was markedly dependent on temperature, but it was not inhibited by 2,4-dinitrophenol (5 x 10(-3)m) and sodium azide (10(-2)m). Omission of the substrate, alpha-ketoglutarate, from the incubation mixture had no inhibitory effect on arsenite uptake. Treatment of the resistant cells with cetyl-trimethylammonium bromide facilitated the uptake of arsenite by the cells. When the sensitive cells accumulating radioactive arsenite were fractionated by the Schmidt-Thanhauser-Schneider method, the large amount of intracellular arsenite was found in the cold perchloric acid-insoluble hot acid-extractable fraction. The arsenite complex with cellular macromolecular constituents cannot be solubilized by treatment with ribonuclease, deoxyribonuclease, and trypsin.
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PMID:DECREASED PERMEABILITY AS THE MECHANISM OF ARSENITE RESISTANCE IN PSEUDOMONAS PSEUDOMALLEI. 1419 80