FIGURE 2.

A and B, primer extension by pol II and pol IV, respectively. Time course primer extension experiments were conducted using non-damaged and ICL DNA substrates (ICL1, ICL2, ICL3, and ICL4). A –10 primer (10 bases upstream of the adduct site) was annealed to the DNA template and incubated with pol II or pol IV (0.3 nm) for the indicated times. C, primer extension activity by pol IV is dose-dependent. The experiment was conducted using non-damaged and ICL1–4 templates primed with the –10 primer with increasing concentrations of pol IV at 37 °C for 30 min. M indicates the oligodeoxynucleotide size marker (Fisher).