Fig. 7.
Proposed alternative molecular models for 8-oxodG-mediated DSB formation at ODCL. A DSB could be formed from two SSBs localized on opposite DNA strands. These two SSBs could be generated by either: (A) the BER of a 8-oxodG on one strand and 8-oxodG-mediated TOP-DPC formation on the other strand; (B) BER of two proximal 8-oxodG localized on opposite strands; (C) BER of two distant 8-oxodG localized on different strands, followed by DNA resection and fill-in processes, mediated by the 3′–5′exonuclease activity of APE1/APE2 and by a DNA polymerase, respectively. Arrows indicate the 8-oxodG involved in the generation of SSBs. The red dashed lines indicate DSBs.