Abstract
The RNA-directed DNA polymerase of murine mammary tumor virus, a type B RNA tumor virus, was purified sequentially through DEAE-cellulose, phosphocellulose (step gradient), and phosphocellulose (linear salt gradient) chromatography, followed by glycerol sedimentation centrifugation. During all stages of purification, coincident peaks of RNA-directed DNA polymerase activity, templated by polyribocytidylate.oligodeoxyguanidylate, and RNase H digestion of [3H]polyriboadenylate.polydeoxythymidylate were observed, and both enzymatic activities displayed a cation preference for magnesium. Under conditions that removed adventitiously associated nucleases, RNase H activity was found to co-purify with polymerase. The specificity of this nuclease was assayed with various prepared substrates, which indicated that the polymerase-associated RNase H activity was directed only against the RNA strand of an RNA.DNA hybrid. It is highly probable that RNase H (RNA.DNA hybrid: ribonucleotide-hydrolase) and RNA-directed DNA polymerase of type B viruses are associated enzymatic activities analogous to those observed for avian and mammalian type C RNA tumor viruses.
Original language | English (US) |
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Pages (from-to) | 187-193 |
Number of pages | 7 |
Journal | Journal of virology |
Volume | 22 |
Issue number | 1 |
DOIs | |
State | Published - 1977 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Microbiology
- Immunology
- Insect Science
- Virology