Fig. 2.

Biphasic kinetics of correct dTTP incorporation by hPolε and p261N at 20 °C. A pre-incubated solution of 10 nM hPolε (●) or p261N (■) and 40 nM 5′-radiolabeled D-1 DNA was rapidly mixed with 5 μM dTTP and 8 mM Mg²⁺ and quenched after various times with 0.37 M EDTA. The data were fit to Eq. (1) to yield burst phase rate constants of 90 ± 28 s⁻¹ and 101 ± 14 s⁻¹ and linear phase rate constants of 0.047 ± 0.006 s⁻¹ and 0.018 ± 0.004 s⁻¹ for hPolε and p261N, respectively.