title: Drosophila topoisomerase I: isolation, purification and characterization.
abstract: We have purified and characterized topoisomerase I from Drosophila melanogaster. The molecular weight of the enzyme is 135,000; 100,000, 90,000, and 65,000 molecular weight products result from degradation of the enzyme. The enzyme relaxes both positive and negative supercoiled DNA. Mg++ is not absolutely required, but stimulates the enzymatic activity considerably.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D004264:DNA Topoisomerases, Type I / Q000302:isolation & purification*; D004331:Drosophila melanogaster / Q000201:enzymology*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008970:Molecular Weight
chemical_list: D004264:DNA Topoisomerases, Type I; D008274:Magnesium