Figure 5.

Initiation of human NER at a site-directed pivaloyl C4′ adduct. Excision repair reactions in HeLa cell extract were performed for 40 min at 30°C. The sequence context is indicated, with the asterisks denoting the site of C4′ backbone modification. Lanes 4 and 5 show results obtained with two independent substrate preparations. The size of oligonucleotide excision products was estimated from the same 19-mer marker used in the experiments of Fig. 3. For comparison, lane 6 represents a control reaction with the site-directed AAF–C⁸–guanine adduct.