Figure 1.

Damage-specific binding and excision. (A) Binding of human excision repair factors to damaged DNA. Repair factors were incubated for 30 min with either a 136-bp control DNA or a duplex containing (6–4) photoproduct and were analyzed on a nondenaturing gel (lanes 1–14). (B) Excision reaction by repair factors used in binding assay. The (6–4) substrate was incubated for 2 h with the five repair factors (RFI–V: XPA, RPA, TFIIH, XPC, XPG) at the concentration used in binding experiment and XPF⋅ERCC1 (RFVI). Excision products were analyzed on 8% denaturing polyacrylamide gel. Quantitative analysis shows that 93% of the damage was excised.