In nucleotide excision repair, damaged dna is excised by what enzyme(s)? in nucleotide excision repair, damaged dna is excised by what enzyme(s)? ligase nuclease dna polymerases primase helicase
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In nucleotide excision repair (NER), the main enzymes involved in excising the damaged DNA are the nucleases. Specifically, endonucleases cut the damaged DNA strand at positions flanking the damage. In humans and many other eukaryotic organisms, the entire set of proteins that recognize and remove the damaged nucleotides is called the excision repair complex. Some of the critical components include XPC (xeroderma pigmentosum group C), which recognizes the distortion in the DNA, and the TFIIH complex, which contains the XPB and XPD helicases that unwind the DNA. Endonucleases such as XPG and ERCC1-XPF are responsible for making incisions that remove the oligonucleotide containing the lesion.
After the damaged section of DNA is removed, DNA polymerase fills in the gap with new nucleotides, using the undamaged strand as a template. Finally, DNA ligase seals the nick to restore the integrity of the DNA strand. Primase, which assembles RNA primers during DNA replication, is not involved in NER.