Fig. 3.

Metal-dependent DNA cleavage by D163I. R.KpnI or D163I (15 nM) was incubated with 0.2 pmol of labeled oligonucleotides containing canonical sequence (-GGTACC-) or pUC18 DNA (1 μg). The reaction was initiated with various concentrations of Mg²⁺ as indicated, and the products were separated by electrophoresis on 12% urea–acrylamide gel or 1% agarose gel. S, L, and O indicate the respective positions of the supercoiled, linear, and open circular forms of the plasmid. (A) Graph depicting the activation profile of WT and D163I at Mg²⁺ concentrations ranging from 0.01 to 1 mM. (B) pUC18 DNA cleavage profiles with increasing concentrations of Mg²⁺ (0.05–5 mM).