title: RNA-dependent RNA polymerase activity in murine coronavirus-infected cells.
abstract: The multiplication of murine coronavirus strains A59 or JHM in Sac(-) cells was unaffected by the presence of alpha-amanitin at concentrations which inhibited the host cell DNA-dependent RNA polymerase activity. In cells infected with the A59 virus strain, actinomycin D-resistant RNA synthesis could readily be detected by pulse-labelling with [3H]uridine; this virus-specific RNA synthesis was not induced in the presence of the protein synthesis inhibitor anisomycin. A new RNA-dependent RNA polymerase activity was detected in the large particle fraction of A59 virus-infected cells. Optimal conditions for enzyme activity in vitro were established. Maximum activity occurred 5 h after infection, coincident with the peak of virus-specific RNA synthesis detected by pulse-labelling in vivo.
mesh_terms: D000546:Amanitins / Q000494:pharmacology; D000818:Animals; D000841:Anisomycin / Q000494:pharmacology; D002460:Cell Line; D003609:Dactinomycin / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D051379:Mice; D006517:Murine hepatitis virus / Q000201:enzymology* / Q000254:growth & development; D012316:RNA Nucleotidyltransferases / Q000378:metabolism*; D012367:RNA, Viral / Q000096:biosynthesis*; D012324:RNA-Dependent RNA Polymerase / Q000378:metabolism*; D013696:Temperature
chemical_list: D000546:Amanitins; D012367:RNA, Viral; D003609:Dactinomycin; D000841:Anisomycin; D012316:RNA Nucleotidyltransferases; D012324:RNA-Dependent RNA Polymerase; D008274:Magnesium