PLANT VIRUS-INDUCED RNA POLYMERASE - PROPERTIES OF ENZYME PARTLY PURIFIED FROM CUCUMBER COTYLEDONS INFECTED WITH CUCUMBER MOSAIC VIRUS

A method has been described for the partial purification from cucumbers infected with cucumber mosaic virus, of a virus-induced RNA polymerase which was free from detectable ribonucleases. Evidence presented indicates that the RNA polymerase purified in this manner had a molecular weight of 123,000 and was not associated with a viral RNA template. RNA polymerase activity was dependent on the presence of added RNA but was not specific for any of the RNA samples used. Nearest neighbour analysis of the product obtained using two RNA samples of different base composition as well as a study of nucleoside triphosphate incorporation in the presence of polycytidylic acid and polyuridylic acid indicated that the product was formed by complementary base pairing with the added RNA. The product was found to be a polyribonucleotide of which 80-90% was resistant to digestion by pancreatic ribonuclease. © 1969.