FIGURE 6.

FEN1 processing of substrates containing flaps of 45 nt under single-turnover conditions. A, representative single-turnover time courses of FEN1 acting upon 45M (filled diamonds) and 45R (open diamonds). B, representative autoradiograms depicting cleavage of 45M (top panel) and 45R (bottom panel). The 0 reaction time is a negative control (see “Experimental Procedures”). 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.