FIG. 7.

trs endonuclease and helicase activities of D412A-68 and Rep68H6 as a function of magnesium concentration. (A) Endonuclease reactions were performed as described for Fig. 5B and carried out in triplicate. Nicking buffer contained 1 nM substrate (³²P-TR) with a double-stranded (ds) nicking site (trs), 3 nM protein, and the indicated [Mg²⁺]. (B) Helicase assays were performed as described for Fig. 5C and carried out in triplicate in nicking buffer that contained 1 nM helicase substrate (M13/24), 3 nM protein, and the indicated [Mg²⁺]. (C) Nicking reactions were performed as described for Fig. 5B and carried out in triplicate. Nicking buffer contained 1 nM substrate (³²P-TRss) with a single-stranded (ss) nicking site (trs), 3 nM protein, and the indicated [Mg²⁺].