Base excision repair

DNA N-glycosylase and AP (apurinic) endonuclease remove mismatched and damaged nucleotides from DNA
DNA N-glycosylase and AP (apurinic) endonuclease remove mismatched and damaged nucleotides from DNA


5'7 AGTCICTTAG f3' 3'1 TCAG_TGAATC L5’ 5'7F—7AGTCGACTTAG [3' 3'11 TCAGEITGAATC /L5’ 1 5’7f——7AGTCGACTTAG f3' 3’_/[TCAG|;|TGAATC lLS’ V\Nick 5’7/———]AGTCGACTTAG f3' ’TATAAT ' 3chece c/Ls Nick-translated segment 0 DNA N-glycosylase recognizes a base- pair mismatch... 9 ...and removes the incorrect uracil, creating an AP (apyrimidinic) site. 9 AP endonuclease generates a single- stranded nick on 5’ side of the AP site... 0 ...and DNA polymerase removes and replaces several nucleotides of the nicked strand by nick translation.