Purification, characterization, and comparison of the DNA polymerases from two primate RNA tumor viruses.
The DNA polymerase from the Mason-Pfizer monkey virus (M-PMV), an RNA tumor virus not typical type-C or type-B, has been purified a thousand-fold over the original crude viral suspension. This purified enzyme is compared to a similarly purified DNA polymerase from the primate woolly monkey virus, a type-C virus. The two enzymes have similar template specificities but differ in their requirements for optimum activity. Both DNA polymerases have a pH optimum of 7.3 in Tris buffer. M-PMV enzyme has maximum activity with 5 mM Mg(2+) and 40 mM potassium chloride, whereas the woolly monkey virus optima are 100 mM potassium chloride with 0.8 mM Mn(2+). The apparent molecular weight of the M-PMV enzyme is approximately 110,000, whereas the woolly monkey virus polymerase is approximately 70,000. The biochemical properties of these two enzymes were also compared to a similarly purified enzyme from a type-C virus from a lower mammal (Rauscher murine leukemia virus). The results show that more similarity exists between the DNA polymerases from viruses of the same type (type-C), than between the polymerases from viruses of different types but from closely related species.
D000818:Animals; D002499:Centrifugation, Density Gradient; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D000882:Haplorhini; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D008970:Molecular Weight; D009858:Oncogenic Viruses / Q000201:enzymology*; D011189:Potassium Chloride / Q000378:metabolism; D012328:RNA Viruses / Q000201:enzymology*; D012194:RNA-Directed DNA Polymerase / Q000032:analysis / Q000302:isolation & purification* / Q000378:metabolism; D011925:Rauscher Virus / Q000201:enzymology; D012190:Retroviridae / Q000201:enzymology*; D013698:Templates, Genetic; D014158:Transcription, Genetic
D008345:Manganese; D011189:Potassium Chloride; D012194:RNA-Directed DNA Polymerase; D008274:Magnesium