Nucleotide excision repair is a
DNA repair mechanism.
DNA damage occurs constantly because of chemicals (e.g.
intercalating agents),
radiation and other
mutagens. Three excision repair pathways exist to repair single stranded DNA damage: Nucleotide excision repair (NER),
base excision repair (BER), and
DNA mismatch repair (MMR). While the BER pathway can recognize specific non-bulky lesions in DNA, it can correct only damaged bases that are removed by specific glycosylases. Similarly, the MMR pathway only targets mismatched Watson-Crick
base pairs.