Nucleotide Excision Repair

A cut is made on both sides of the damaged DNA, sometimes 30 nucleotides long. A helicase is then used to remove the fragment from DNA. DNA polymerase adds new nucleotides to the gap using the opposite strand as template, and DNA ligase seals the strand.

There are two groups of nucleotide excision repair mechanisms that use similar tools but act at different locations:

1. Global genomic repair
2. transcription-coupled repair