title: A type I DNA topoisomerase from Trypanosoma cruzi.
abstract: A type I DNA topoisomerase has been isolated from the nuclei of the flagellate Trypanosoma cruzi, using poly(ethylene glycol) fractionation and chromatography on hydroxyapatite and on phosphocellulose. The relaxation activity was ATP-independent, enhanced by Mg2+ and spermidine. The enzyme removed supercoils from negative and positive superhelical DNAs. Topoisomerase activity was associated with a polypeptide of Mr about 65000 as shown by glycerol gradient centrifugation and by electrophoresis on sodium dodecyl sulfate/polyacrylamide gels.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D002499:Centrifugation, Density Gradient; D004264:DNA Topoisomerases, Type I / Q000302:isolation & purification*; D004591:Electrophoresis, Polyacrylamide Gel; D010455:Peptides / Q000302:isolation & purification; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D010455:Peptides; D004264:DNA Topoisomerases, Type I