Virion DNA-independent RNA polymerase from Saccharomyces cerevisiae.
The "killer" plasmid and a larger double-stranded RNA plasmid of yeast exist in intracellular virion particles. Purification of these particles from a diploid killer strain of yeast (grown into stationary growth on ethanol) resulted in co-purification of a DNA-independent RNA polymerase activity. This activity incorporates and requires all four ribonucleoside triphosphates and will not act on deoxyribonucleoside triphosphates. The reaction requires magnesium, is inhibited by sulfhydryl-oxidizing reagents and high concentrations of monovalent cation, but is insensitive to DNase, alpha-amanitin, and actinomycin D. Pyrophosphate inhibits the reaction as does ethidium bromide. Exogenous nucleic acids have no effect on the reaction. The product is mostly single-stranded RNA, some of which is released from the enzymatically active virions.
D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D008854:Microscopy, Electron; D010957:Plasmids; D012330:RNA, Double-Stranded / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D013379:Substrate Specificity; D014771:Virion / Q000201:enzymology*
D012330:RNA, Double-Stranded; D012367:RNA, Viral; D012321:DNA-Directed RNA Polymerases