Abstract
Purified reverse transcriptase from avian myeloblastosis virus or Rous sarcoma virus consists of two subunits of average mol wt of 100,000 and 60,000. The lower-molecular-weight subunit, alpha, has been isolated from avian myeloblastosis virus, Rous sarcoma virus and a temperature-sensitive mutant of Rous sarcoma virus, LA337. Subunit alpha manifests both the DNA polymerase and RNase H activities associated with purified reverse transcriptase of avian RNA tumor viruses. The thermal inactivation of these enzymatic activities of alpha subunit from the wild-type virus. The results show that both DNA polymerase and RNase H activities associated with the alpha subunit of LA337 are five to seven times more thermolabile then the corresponding alpha subunit from the wild-type virus. It is concluded that (i) both the polymerase and nuclease activities reside on the same polypeptide chain, and (ii) at least the lower-molecular-weight subunit alpha is coded for by the viral RNA.
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- Baltimore D., Huang A. S., Stampfer M. Ribonucleic acid synthesis of vesicular stomatitis virus, II. An RNA polymerase in the virion. Proc Natl Acad Sci U S A. 1970 Jun;66(2):572–576. doi: 10.1073/pnas.66.2.572. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Baltimore D., Smoler D. F. Association of an endoribonuclease with the avian myeloblastosis virus deoxyribonucleic acid polymerase. J Biol Chem. 1972 Nov 25;247(22):7282–7287. [PubMed] [Google Scholar]
- Faras A. J., Taylor J. M., McDonnell J. P., Levinson W. E., Bishop J. M. Purification and characterization of the deoxyribonucleic acid polymerase associated with Rous sarcoma virus. Biochemistry. 1972 Jun 6;11(12):2334–2342. doi: 10.1021/bi00762a020. [DOI] [PubMed] [Google Scholar]
- Grandgenett D. P., Gerard G. F., Green M. A single subunit from avian myeloblastosis virus with both RNA-directed DNA polymerase and ribonuclease H activity. Proc Natl Acad Sci U S A. 1973 Jan;70(1):230–234. doi: 10.1073/pnas.70.1.230. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Grandgenett D. P., Green M. Different mode of action of ribonuclease H in purified alpha and alpha beta ribonucleic acid-directed deoxyribonucleic acid polymerase from avian myeloblastosis virus. J Biol Chem. 1974 Aug 25;249(16):5148–5152. [PubMed] [Google Scholar]
- Hurwitz J., Leis J. P. RNA-dependent DNA polymerase activity of RNA tumor viruses. I. Directing influence of DNA in the reaction. J Virol. 1972 Jan;9(1):116–129. doi: 10.1128/jvi.9.1.116-129.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jovin T. M., Englund P. T., Bertsch L. L. Enzymatic synthesis of deoxyribonucleic acid. XXVI. Physical and chemical studies of a homogeneous deoxyribonucleic acid polymerase. J Biol Chem. 1969 Jun 10;244(11):2996–3008. [PubMed] [Google Scholar]
- Kacian D. L., Watson K. F., Burny A., Spiegelman S. Purification of the DNA polymerase of avian myeloblastosis virus. Biochim Biophys Acta. 1971 Sep 24;246(3):365–383. doi: 10.1016/0005-2787(71)90773-8. [DOI] [PubMed] [Google Scholar]
- Linial M., Mason W. S. Characterization of two conditional early mutants of Rous sarcoma virus. Virology. 1973 May;53(1):258–273. doi: 10.1016/0042-6822(73)90484-4. [DOI] [PubMed] [Google Scholar]
- Temin H. M., Baltimore D. RNA-directed DNA synthesis and RNA tumor viruses. Adv Virus Res. 1972;17:129–186. doi: 10.1016/s0065-3527(08)60749-6. [DOI] [PubMed] [Google Scholar]
- Verma I. M., Mason W. S., Drost S. D., Baltimore D. DNA polymerase activity from two temperature-sensitive mutants of Rous sarcoma virus is thermolabile. Nature. 1974 Sep 6;251(5470):27–31. doi: 10.1038/251027a0. [DOI] [PubMed] [Google Scholar]
- Verma I. M., Meuth N. L., Fan H., Baltimore D. Hamster leukemia virus: lack of endogenous DNA synthesis and unique structure of its DNA polymerase. J Virol. 1974 May;13(5):1075–1082. doi: 10.1128/jvi.13.5.1075-1082.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]