Repair of 5-OHU in reconstituted system. (A) For α-32PdTMP incorporation into 5-OHU-containing plasmid DNA, 10 pmol substrates were incubated with combinations of 0.5 pmol of NEIL2, 25 fmol of PNK, 25 fmol APE1 and 0.25 pmol of other proteins as described in Section 2. Repaired plasmid was linearized with AhDI and analyzed on 0.8% agarose gel. Lane 1, undamaged DNA and lanes 2–8, 5-OHU-containing plasmid DNA. Complete repair is indicated by the radioactive dTMP incorporation. The agarose gel was dried and the reactions products were analyzed by PhosphorImager. Lane 9, end-labeled 1 kb DNA ladder (NEB). (B) Repair of 5-OHU-containing plasmid DNA with vector (lanes 1 and 2 µl, respectively; 5 and 10 µl, respectively) and FLAG-NEIL2 immunoprecipitate (lanes 3 and 4 µl, respectively; 5 and 10 µl, respectively). Lane 5, end-labeled 1 kb DNA ladder (New England Biolabs).