Figure 3.

Nucleotide selection during insertion opposite 8oxodG. Here, 12, 30 and 18 nM of Pol^wtExo⁻, Pol^Y390FExo⁻ and Pol^Y390SExo⁻ mutants, respectively, were incubated at 25°C for 15 s with 1.2 nM of the hybrid molecule depicted on top of the figure and in the presence of the indicated concentrations of either dATP or dCTP (see Materials and Methods section). Formation of the extended product was plotted against dNTP concentration. Inset, electrophoretic analysis of the primer extension experiments at the corresponding nucleotide concentration indicated below. Each data set was fit by least-squares nonlinear regression to a rectangular hyperbola.