期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：1
页码：230-234
DOI：10.1073/pnas.70.1.230
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Two structurally distinct forms of RNA-directed DNA polymerase from avian myeloblastosis virus were resolved by chromatography on phosphocellulose and purified. In addition to RNA-directed DNA polymerase activity, both enzymes had ribonuclease H (RNase H) activity, which degraded the RNA moiety of RNA{middle dot}DNA hybrids. As determined by sodium dodecyl sulfate-polyacrylamide disc-gel electrophoresis, one form had two subunits, alpha ([α]) and beta ({beta}), with molecular weights of 65,000 and 105,000, respectively. The other had a single subunit, [α], with a molecular weight of 65,000. The sedimentation coefficients of [α]{beta} and [α], determined by glycerol gradient centrifugation in 0.35 M KCl, were 7.8 S and 5.2 S, respectively. Both enzymes had similar antigenic determinants and could not be distinguished by a differential response to several different RNA and DNA templates. We suggest that [α], which contains both RNA-directed DNA polymerase and RNase H activity, is derived by dissociation of [α]{beta}; the function of the {beta} subunit is unknown.
关键词：RNA virus ; polyacrylamide gel electrophoresis
