FIGURE 2.

G231D pol β does not display biphasic burst kinetics. Pre-steady state kinetics was performed by incubating 100 μm 45AG DNA (Table 1) and 100 μm dTTP with 300 μm WT (A, filled circles) or G231D (B, open triangles) pol β. WT pol β reactions were on a time course ranging from 0.01 to 1 s, and G231D reactions ranged from 1 to 120 s. Products were resolved on 20% denaturing gels and imaged using a phosphorimager and quantified. Data were plotted as product formed versus time and fit to the full burst equation (WT) or single exponential (G231D). (WT, k_obs = 14 ± 3 s⁻¹; G231D, k_obs = 0.11 ± 0.01 s⁻¹).