Purification and characterization of bovine leukemia virus DNA polymerase.
An RNA-directed DNA polymerase was purified from bovine leukemia virus (BLV) by successive glycerol gradient centrifugation, column chromatography on phosphocellulose and gel filtration on Sephadex G-200. The purified DNA polymerase transcribes heteropolymeric regions of 30--40 S RNA isolated from avian myeloblastosis virus. The enzyme differs from other known DNA polymerases of mammalian type-C RNA tumor viruses by the following properties: 1. Its apparent molecular weight as estimated by velocity sedimentation data is 58,000 at 0.12 M KCl and 43,000 in the presence of 0.50 M KCl. 2. It has a Mg2+ optimum of 10 mM, and a Mn2+ optimum of 0.25 mM with (rA)n-(dT)10 as template. 3. At 50 mM KCl it is inhibited more than 70%, but it is not inhibited by phosphate ions at 2 mM. These properties confirm the peculiar position of BLV within the family Retraviridae.
D000818:Animals; D009189:Avian Myeloblastosis Virus; D002417:Cattle; D004259:DNA-Directed DNA Polymerase / Q000302:isolation & purification*; D004791:Enzyme Inhibitors; D001909:Leukemia Virus, Bovine; D008274:Magnesium / Q000032:analysis; D008345:Manganese / Q000032:analysis; D008970:Molecular Weight; D011188:Potassium / Q000032:analysis; D012367:RNA, Viral / Q000378:metabolism; D012190:Retroviridae
D004791:Enzyme Inhibitors; D012367:RNA, Viral; D008345:Manganese; D004259:DNA-Directed DNA Polymerase; D008274:Magnesium; D011188:Potassium