title: Transcription in yeast: separation and properties of multiple FNA polymerases.
abstract: Four peaks of DNA-directed RNA polymerase activity are resolved by salt gradient elution of a sonicated yeast cell extract on DEAE-Sephadex. The enzymes, which are named IA, IB, II, and III in order of elution, all appear to come from cell nuclei. Only enzyme II is sensitive to alpha-amanitin. All enzymes are more active with Mn(++) than with Mg(++) as divalent ion. Enzymes IB and II have salt optima in the range 0.05-0.10 M (NH(4))(2)SO(4), whereas enzyme III is maximally active at 0.20-0.25 M (NH(4))(2)SO(4). With optimal salt concentration and saturating DNA, the template preference ratio, activity on native calfthymus DNA divided by activity on denatured calf-thymus DNA, is 2.2 for IB, 0.4 for II, and 3.5 for III. None of the yeast polymerases was inhibited by rifamycin SV. Rifamycin AF/013 effectively inhibited polymerases IB, II, and III.
mesh_terms: D000645:Ammonium Sulfate; D002852:Chromatography, Ion Exchange; D004247:DNA; D004789:Enzyme Activation; D008274:Magnesium; D008345:Manganese; D009183:Mycotoxins; D009691:Nucleic Acid Denaturation; D009994:Osmolar Concentration; D012316:RNA Nucleotidyltransferases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D012293:Rifampin; D012440:Saccharomyces / Q000201:enzymology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013698:Templates, Genetic; D014316:Tritium; D014500:Uracil Nucleotides
chemical_list: D009183:Mycotoxins; D014500:Uracil Nucleotides; D014316:Tritium; D008345:Manganese; D004247:DNA; D012316:RNA Nucleotidyltransferases; D008274:Magnesium; D000645:Ammonium Sulfate; D012293:Rifampin