title: Host and virus specific RNA polymerases in alfalfa mosaic virus infected tobacco.
abstract: The particulate fraction of a homogenate of alfalfa mosaic virus infected tobacco was found to contain the viral replicase, and one or more host-specific RNA-polymerases. Using an endogeneous template, the membrane-bound replicase incorporates 3H-CTP in virion-type RNA. The synthesized RNA is part of a replicative intermediate; after RN-ase-treatment the product comigrates with viral double-stranded RNA in polyacrylamide gels. A preliminary characterization of this double-stranded RNA was made by RNA-RNA hybridization. Treatment of the particulate fraction with lubrol releases a host-specific RNA-polymerase. The activity of this enzyme is completely dependent on exogeneous template-RNA. Probably only a very small region of the template is transcribed. After washing with lubrol, the particulate fraction still contains the viral replicase. When this fraction is resuspended in a Mg++-deficient buffer, about 60% of the enzyme activity is released into the supernatant. No such activity is found in a comparable extract of healthy leaves.
mesh_terms: D003597:Cytosine Nucleotides / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000032:analysis*; D003902:Detergents / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D008566:Membranes / Q000201:enzymology; D009029:Mosaic Viruses / Q000201:enzymology*; D009693:Nucleic Acid Hybridization; D010942:Plant Viruses / Q000201:enzymology*; D010947:Plants, Toxic; D012367:RNA, Viral / Q000096:biosynthesis*; D012324:RNA-Dependent RNA Polymerase / Q000032:analysis; D012260:Ribonucleases; D013698:Templates, Genetic; D014026:Nicotiana / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology*; D014779:Virus Replication
chemical_list: D003597:Cytosine Nucleotides; D003902:Detergents; D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase; D012321:DNA-Directed RNA Polymerases; D012260:Ribonucleases; D008274:Magnesium