BER corrects ~10,000 lesions/cell/day from hydrolysis, oxidation, and alkylation. DNA glycosylase recognizes the damaged base and flips it out of the helix into a recognition pocket, cleaving the N-glycosidic bond. AP endonuclease cuts the phosphodiester backbone at the abasic site. DNA polymerase β fills the gap, and DNA ligase III seals the nick. ROS-damaged 8-oxoguanine pairs with adenine before repair — the MUTYH glycosylase removes the mispaired A.
Repair events in this session
Active lesions on strand
Steps/second current pathway