FIGURE 6.
The ZnF domain added in trans inhibits DNA ligation by ΔZnF LigIII. A, increasing concentrations of the ZnF were added to reactions containing ΔZnF (20 nm) and a nicked DNA substrate (4 nm). Ligation of the 15- and 13-mer strands of the substrate generates a 28-mer product that was detected during the time course of the reaction (5 s, 30 s, 1 min, 5 min, 10 min, and 50 min). B, the observed rate constants (kobs) for ligation were determined in the presence of the different ZnF concentrations shown. Increasing concentrations of ZnF inhibit end joining activity by the ΔZnF enzyme.