Figure 6.

Bypass of AAF-guanine by human Polκ. (A) DNA polymerase assays were performed with purified human Polκ using undamaged template (lane 1) or the AAF-damaged template (lane 2), both of which shared identical nucleotide sequence. The ³²P-labeled ‘running start’ primer was annealed 4 nt before the AAF-G as indicated. Polκ used was 10 ng (100 fmol) and 20 ng (200 fmol) for lanes 1 and 2, respectively. The 18mer DNA band extended opposite the template AAF-G is indicated by an arrowhead. (B) DNA polymerase assays were performed with purified human Polκ (10 ng, 100 fmol) using the indicated DNA substrate containing a template AAF-G and a ³²P-labeled 17mer primer. Polymerase reactions were carried out in the presence of a single deoxyribonucleoside triphosphate dATP (lane 3), dCTP (lane 4), dTTP (lane 5) or dGTP (lane 6) or all four dNTPs (lane 2). Lane 1, control reaction without Polκ. DNA size markers in nucleotides are indicated on the left.