FIGURE 2.

Extension of ³²P-labeled primers opposite templates containing unmodified dA or 1,N⁶-γ-HMHP-dA adduct by hpol κ (A), hpol η (B), and Dpo4 (C). The 13-mer primers (Scheme 2) were annealed with 18-mer template containing either unmodified dA or 1,N⁶-γ-HMHP-dA adduct. The resulting primer-template complexes (50 nm) were incubated in the presence of hpol κ, hpol η (5 nm), or Dpo4 (25 nm). The polymerase reactions were started by the addition of the four dNTPs (500 μm) and quenched at the indicated time points. The quenched samples were separated by 20% (w/v) denaturing PAGE and visualized by phosphorimaging analysis. X represents the migration of the starting primer.