title: DNA-dependent RNA polymerase C from Xenopus laevis ovaries. Ability to transcribe intact double-stranded DNA.
abstract: DNA-dependent RNA polymerase C, partially purified from Xenopus laevis ovaries, has been resolved by DEAE-Sephadex chromatography in two forms, eluting at 0.2 M and 0.3 M ammonium sulfate, respectively. Both are sensitive to high concentrations of alpha-amanitin (200 mug/ml). Their ionic strength dependence and divalent cation requirements are indistinguishable. Quantitatively, RNA polymerase C represents the major form of RNA polymerase activity solubilized from the ovaries. Both RNA polymerases C are able to transcribe efficiently either high-molecular-weight Xenopus DNA or intact adenovirus DNA, as compared to nicked DNA. In contrast, RNA polymerase A has little activity on an intact DNA template. The salt dependence of the RNA polymerases C activity is different on the two kinds of template. Nicked DNA is efficiently transcribed up to a salt concentration of 100 mM ammonium sulfate. On intact DNA, optimal transcription is obtained at 40 mM ammonium sulfate and is inhibited by higher salt concentrations.
mesh_terms: D000546:Amanitins / Q000494:pharmacology; D000645:Ammonium Sulfate / Q000494:pharmacology; D000818:Animals; D004247:DNA / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000302:isolation & purification / Q000378:metabolism*; D003851:Deoxyribonucleases / Q000378:metabolism; D005260:Female; D007700:Kinetics; D008970:Molecular Weight; D009994:Osmolar Concentration; D010053:Ovary / Q000201:enzymology*; D012260:Ribonucleases / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014981:Xenopus
chemical_list: D000546:Amanitins; D004279:DNA, Viral; D004247:DNA; D012321:DNA-Directed RNA Polymerases; D003851:Deoxyribonucleases; D012260:Ribonucleases; D000645:Ammonium Sulfate