title: A DNA topoisomerase activity copurifies with the DNA polymerase induced by herpes simplex virus.
abstract: A DNA-relaxing enzyme was found to copurify along with herpes simplex virus type I (HSV-1)-induced DNA polymerase throughout a multistep purification scheme. Both the enzymes had similar sedimentation velocity, required high ionic strength for optimal enzymatic activities and showed time dependence of reaction. The DNA-relaxing enzyme however, differed from the HSV-1 DNA polymerase in its requirement for higher Mg2+ concentration, rATP and much broader pH dependence. Furthermore, phosphonoacetic acid, a potent inhibitor of HSV-1 DNA polymerase did not influence the DNA-relaxing activity even at a much higher concentration. On the other hand, the DNA-relaxing enzyme associated with the DNA polymerase may be specified by HSV-1 since IgG fraction of rabbit antisera against the virus-infected cells but not against the mock-infected cells strongly inhibited both the enzymatic activities. Thus, HSV-1-induced DNA polymerase which is known to be associated with a 3' to 5' exonuclease may also be associated with yet another enzymatic activity involved in DNA metabolism.
mesh_terms: D000818:Animals; D004264:DNA Topoisomerases, Type I / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004790:Enzyme Induction; D006863:Hydrogen-Ion Concentration; D007668:Kidney; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D008970:Molecular Weight; D011817:Rabbits; D018139:Simplexvirus / Q000201:enzymology*
chemical_list: D015636:Magnesium Chloride; D004259:DNA-Directed DNA Polymerase; D004264:DNA Topoisomerases, Type I; D008274:Magnesium