Figure 2.

Effect of the presence of an opposite AP site or reduced AP site on the efficiency of excision of 8-oxoG by yOGG1. The oligonucleotide containing an 8-oxoG was labelled and hybridised to a complementary strand containing either the complementary base (control) or another uracil opposite the positions between 5 bases 5′ (–5) and 5 bases 3′ (+5) from the 8-oxoG on the labelled strand (see Table 1). Double-stranded oligonucleotides were treated with UDG to create an AP site at the various uracil positions before (A) or after (B) treatment with NaBH₄ to reduce the AP site. The oligonucleotides were then subjected to excision of 8-oxoG using yOGG1 (100–500 pg). The fold inhibition/activation was obtained from comparison with the control containing no other damage on the non-labelled strand. The error bars represent the standard deviation from three to five different experiments.