FIGURE 6.

Processivity of wild-type gp5, gp5-C275S, and gp5-C313S. Processivity assays were carried out on a M13 ssDNA primed with a 5′ ³²P-labeled 24-nt primer in the presence of trx as described under “Experimental Procedures.” DNA synthesis reactions (100 μl) contained 50 mm Tris-HCl, pH 7.5, 5 mm DTT, 50 mm NaCl, 10 mm MgCl₂, 250 μm each of dGTP, dATP, dCTP, and dTTP, 5 nm gp5, 250 nm trx, and 40 nm ³²P-labeled primed M13 ssDNA. Reaction mixtures were incubated at 37 °C. At the indicated times, aliquots (20 μl) were removed, and reactions were stopped by the addition of 25 mm EDTA. The reaction products were separated on a 0.6% alkaline agarose gel.