Abstract
The activity and the processivity in DNA relaxation of DNA topoisomerase II, isolated from cauliflower inflorescence, were examined with various ratios of KCl and MgCl2 concentrations in the reaction medium. The optimum concentrations for the relaxation were found to be 60mM for KCl and 5mM for MgCl2 in the same reaction mixture regarding the other elements. The reaction proceeds in a processive manner at low salt concentration, and in a distributive manner at high concentration, in which MgCl2 exhibits higher efficiency (five-fold) than KCl.
