Deoxyribonucleic acid polymerase associated with Rous sarcoma virus and avian myeloblastosis virus: properties of the enzyme and its product.

Deoxyribonucleic acid (DNA) polymerase activity can be elicited in purified preparations of avian myeloblastosis virus and Rous sarcoma virus (Schmidt-Ruppin strain) by treatment with nonionic detergent. The enzyme(s) and its synthetic products appear to be virion-associated. Enzymatic activity can be inhibited by pretreatment with either ribonuclease (8- to 10-fold inhibition) or actinomycin D (twofold inhibition). By contrast, rifampin has little, if any effect. The enzyme(s) synthesizes two primary products, a ribonucleic acid (RNA):DNA hybrid and DNA which is free of RNA. The results of both zonal and equilibrium centrifugation indicate that nascent chains of DNA are associated with the 70S viral RNA. It is concluded that at least two enzymatic activities are under study: transcription of DNA from viral RNA, and subsequent, additional synthesis of DNA, utilizing product of the initial reaction as template.