Figure 7.

Effect of the presence of an opposite 8-oxoG on the efficiency of excision of an AP site (asterisk denotes that the AP site is on the labelled strand) by the AP lyase activity of the yOGG1 protein. The oligonucleotides containing a uracil on strand 1 at the various positions from –5 to +5 were 5′-end-labelled and hybridised to the complementary strand containing either the complementary base (used as control) or an 8-oxoG at the fixed base on strand 2 (see Table 1). Double-stranded oligonucleotides were treated with UDG to create an AP site at the various uracil positions prior to incubation with 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.