title: Mammalian cells contain a DNA-recombining activity that can be dissociated from topoisomerase activity.
abstract: The role of the topoisomerase enzyme in DNA recombination was investigated by extracting chromosomal deoxyribonucleoproteins from a variety of cultured mammalian cells and assaying for the formation of recombinant DNA structures. Although each of the crude deoxyribonucleoprotein preparations contained topoisomerase activity, they did not all contain DNA-recombining activity. A distinct, perhaps novel, enzyme may therefore promote DNA recombination in these cell-free systems.
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D002843:Chromatin / Q000201:enzymology; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics; D003852:Deoxyribonucleoproteins / Q000502:physiology*; D009698:Nucleoproteins / Q000502:physiology*; D011995:Recombination, Genetic; D013539:Simian virus 40 / Q000235:genetics
chemical_list: D002843:Chromatin; D004279:DNA, Viral; D003852:Deoxyribonucleoproteins; D009698:Nucleoproteins; D004264:DNA Topoisomerases, Type I