title: Purification and characterization of the DNA untwisting enzyme from rat liver.
abstract: The DNA untwisting enzyme has been purified approximately 300-fold from rat liver nuclei. The protein is greater than 90% pure as judged by sodium dodecyl sulfate-acrylamide gel electrophoresis. The native enzyme has a molecular weight between 64 000 and 68 000 and is composed of a single polypeptide chain. Evidence is presented that the protein can act catalytically. A trace amount of endonuclease activity associated with the most pure fraction could be a contaminant or it could be due to the action of the DNA untwisting enzyme itself.
mesh_terms: D000818:Animals; D004270:DNA, Circular; D004279:DNA, Viral; D003851:Deoxyribonucleases / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D011118:Polynucleotide Ligases / Q000302:isolation & purification* / Q000378:metabolism; D051381:Rats; D013539:Simian virus 40; D013050:Spectrometry, Fluorescence
chemical_list: D004270:DNA, Circular; D004279:DNA, Viral; D003851:Deoxyribonucleases; D011118:Polynucleotide Ligases