Partial purification and properties of DNA polymerases from JLS-V10 cells

Abstract

A new DNA polymerase was partially purified from a mouse bone marrow continuous cell line chronically infected with Rauscher leukemia virus (JLS-V10) by sequential column chromatography and gradient centrifugation. The DNA polymerase can be distinguished from other cellular DNA polymerases by its template specificity on oligo(dG) 12· poly(rC) and oligo(dT) 10. The molecular weight of the enzyme is 110,000 as estimated by Sephadex column chromatography. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis the enzyme segregates into two subunits of M r 70,000 and 35,000, respectively. This result was also obtained in Sephadex column chromatography when the enzyme was treated either with guanidine hydrochloride or Triton X-100. The whole enzyme and one of its subunits are inhibited by rabbit-antiserum prepared against Rauscher leukemia virus reverse transcriptase, whereas the other subunit is not. One subunit (70,000 M r ) resembles Rauscher reverse transcriptase, whereas the other subunit (35,000 M r ) is analogous to a low molecular weight DNA polymerase. The above associated phenomenon is probably not an artifact, since in this study a similar enzyme was purified from Rauscher leukemia virus.