FIGURE 3.

DNA polymerase activity of gp5 in the absence of trx. Standard reaction mixtures (20 μl) containing 200 nm dA₃₅₀/dT₂₅ DNA substrate, 250 μm each of dATP, dCTP, dGTP, and [³H]dTTP (10 cpm/pmol), and increasing amounts of the indicated gp5 in the standard reaction mixture containing DTT were incubated at 25 °C for 2 min. The reactions were stopped by the addition of 25 mm EDTA, and the amount of [³H]dTMP incorporated into DNA was determined as described under “Experimental Procedures.” ■, wt gp5; ○, gp5-C275S; ▴, gp5-C313S; ♦, gp5-C275S/C313S.