Panel A: One-base incorporation opposite the adduct site catalyzed by pol κ polymerase. In the presence of all four dNTPs 5’-32P-labeled 18-mer primer 5’-GCGGATCTGGCCAGATAG was extended by pol κ polymerase (see text for experimental conditions) at 30 °C. Unmodified template (UM): lanes 2 – 5, incubation time 15, 30, 60 and 90 min. G*CT* template: lanes 7 – 10, incubation time 15, 30, 60 and 90 min. The 49-mer constitutes a fully extended primer. Positions of the unextended 18-mer are shown in the lanes 1 and 6. Panel B and C: Histograms of the denaturing gel autoradiograph (Panel A) for extension of 18-mer primers on the G*CT* template catalyzed by pol κ polymerase. In each case, the profiles are derived from the respective lanes for 30 min (B), 10 ± 2% average full extensions, and for 90 min (Panel C).