Deoxyribonucleic Acid Polymerase Associated with Rous Sarcoma Virus and Avian Myeloblastosis Virus: Properties of the Enzyme and Its Product

Abstract

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 (8to 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.

Deoxyribonucleic acid polymerase associated with feline leukemia and sarcoma viruses: Properties of the enzyme and its product

“…The presence of a non-ionic detergent in the reaction mixture was required to elicit the polymerase activity. This confirms and extends the reports from other laboratories (Spiegelman et al, 1970b;Mizutani et al, 1970;Riman and Beaudreau, 1970;Spigelman et al, 1970c;McDonnell et al, 1970;Fujinaga et al, 1970;Garapin et al, 1970) that both polymerase activities are associated with, and possibly contained within, the virions of a number of oncogenic RNA viruses. The DNA-dependent activity associated with the feline viruses can function with both natural and synthetic DNA templates.…”

Stable bone‐marrow‐derived cell line producing transforming avian acute leukemia virus OK 10

“…Samples of virus purified by sucrose gradient ultracentrifugation as described (Pettersson et al, 1971) or the cell-free supernatants of virus-infected cells, were added just before the reaction was started. Reaction mixtures were incubated at 41°C for 1 to 4 and h analyzed for acidprecipitable radioactivity (Garapin et al, 1970). Under these conditions purified RSV, Schmidt-Ruppin strain, subgroup A, used as control gave an incorporation of 4 X lo5 c p d l 0 pg virus protein.…”

Effect of viral RNase H on the avian sarcoma viral genome during early transcription in vitro

“…RNase H activity on the viral RNA-DNA hybrid. It is known from previous studies (3,21,26,33,37,51) that the detergent concentration present in an endogenous reaction strongly influences DNA synthesis. Long DNA molecules which are representative of large parts of the genome are synthesized only at the optimum detergent concentration for the reaction (26).…”