Figure 2. Involvement of pol λ and Tdp1 in end processing.
(A to C) Radiolabeled linear DNA molecules with the depicted ends were added to the indicated egg extracts, and reaction samples were stopped at the indicated time points. DNA was extracted, digested, and analyzed by denaturing PAGE and autoradiography. Lower panels, un-joined DNA ends; upper panels, joined DNA ends. Red asterisk indicates radiolabeled strand. Immunodepletion of pol λ alone blocked joining of the ends depicted in (A) (see Figure S1H, lanes 22 to 24). Immunodepleted extracts were supplemented with the following final concentrations of recombinant protein as indicated: pol λ and pol μ, 10 nM; Tdp1, 40 nM. S, input substrate; I, processing intermediate; P, ligation product. Upper panels depict “head-to-tail” joints (see Figure S1B). “Head-to-head” joints show similar products and are shown in Figures S1C, S1E, and S1F.