FIGURE 5.
Single-turnover time course of FEN1 acting upon mixed sequence and TNR flap substrates. A, comparison of mixed sequence flap substrates shows 14M (filled circles), 30M (filled squares), 45M (filled diamonds), and 60M (filled triangles). B, comparison of CAG repeat flap substrates depicts 12R (open circles), 30R (open squares), 45R (open diamonds), and 60R (open triangles). Experimental conditions were 10 nm DNA substrate, 50–200 nm FEN1 (see “Experimental Procedures” for details), 30 mm HEPES-KOH, 40 mm KCl, 8 mm MgCl2, 5% (v/v) glycerol, 0.1 mg/ml BSA, pH 7.4. Reactions were performed at 37 °C using an RQF instrument and quenched with EDTA.