Transcription of 70S RNA by DNA polymerases from mammalian RNA viruses.

DNA polymerases purified by the same procedure from four mammalian RNA viruses, simian sarcoma virus type 1, gibbon ape lymphoma virus, Mason-Pfizer monkey virus, and Rauscher murine leukemia virus are capable of transcribing heteropolymeric regions of viral 70S RNA without any other primer. In this reconstituted system the enzymes from simian sarcoma virus type 1, Mason-Pfizer monkey virus, and Rauscher murine leukemia virus transcribe viral 70S RNA almost as efficiently as the DNA polymerase from the avian myeloblastosis virus, but gibbon ape lymphoma virus DNA polymerase is approximately three-to fivefold less efficient. Although there is a substantial difference among the sizes of these DNA polymerases (160,000 daltons for the avian myeloblastosis virus enzyme, 110,000 daltons for the Mason-Pfizer monkey virus enzyme, and 70,000 daltons for the mammalian type C viral polymerases), the ability to transcribe viral 70S RNA is a characteristic common to these enzymes.     

Purification and characterization of gibbon ape leukemia virus DNA polymerase.

An RNA directed DNA polymerase was purified over 2500 fold from gibbon ape leukemia virus by successive column chromatography on Sephadex G100, DEAE cellulose, phosphocellulose and hydroxyapatite. The purified DNA polymerase has a molecular weight of 68 000, a pH optimum of 7.5, a Mn2+ optimum of 0.8 mM, and KCl optimum of 80 mM. The purified enzyme transcribes heteropolymeric regions of viral 60-70 S RNA isolated from avian myeloblastosis virus, Rauscher murine leukemia virus and simian sarcoma virus and it is inhibited by antiserum prepared against either gibbon ape leukemia virus or simian sarcoma virus DNA polymerases.     

Lack of Sequence Homology Between the 70S RNA of Various RNA Tumor Viruses and the DNA of Simian Virus 40 or Polyoma Virus

No significant hybridization was detected of DNA from simian virus 40 or polyoma virus, and of 70S RNA from avian myeloblastosis virus, murine leukemia virus (Rauscher), murine sarcoma virus (Kirsten), RD-114B, simian sarcoma virus-1, or Mason-Pfizer virus.