Figure 1.

1-Nitropyrene and Y-family DNA polymerase activity. (A) Reduction of 1-Nitropyrene to the nitrenium ion and attachment to a guanine base of DNA to form APG adducts. (B) Primer extension assays with undamaged G or the APG lesion at the first replication position. Human polη, polκ and polι were incubated with DNA substrates and reacted with no incoming nucleotides (0), all four nucleotides (N) or individual nucleotides (A, T, C, G) for either 0.5 min for undamaged G or 30 min for the APG lesion. Vertical arrows indicate nucleotide preferences opposite the APG lesion, and horizontal arrows indicate stalling bands of APG DNA. DNA substrates are shown above the gels.