FIGURE 2.
Stepwise analysis of WRN-mediated stimulation of hpol η activity. hpol η1–437 (2 nm) was incubated with 13/18-mer DNA substrate (200 nm) in either the absence (●) or presence (■) of full-length WRN1–1432 (100 nm). The reaction was initiated by the addition of dNTP (500 μm each dNTP) and MgCl2 (5 mm). Each product band was quantified. The rate of product formation was determined by fitting the data to a stepping equation (Equation 1), where n = 1 or 5 for A the first, and B, the last dNTP insertion event, respectively. The experiments were performed in triplicate and the mean ± S.D. is shown. The single-turnover rate constant for each experiment is shown to the right of the plot.