What process is utilized for DNA damage repair involving nucleotide excision?

Nucleotide excision repair is a crucial cellular mechanism responsible for repairing bulky DNA lesions, such as those caused by UV radiation or chemical damage. This process begins with the detection of the damaged DNA strand. Specific proteins recognize the distortion in the DNA structure, which leads to the recruitment of additional repair factors.

Once the damage is identified, a segment of the DNA strand that includes the damaged nucleotides is excised. This excision typically removes several nucleotides surrounding the lesion to ensure that the entire affected area is removed. After excision, a DNA polymerase synthesizes new nucleotides to fill the gap, using the complementary strand as a template. Finally, DNA ligase seals the newly synthesized segment with the existing DNA strand, restoring the integrity of the DNA molecule.

This repair pathway is particularly important in maintaining genomic stability by preventing mutations that can occur if DNA damage is not properly addressed. The specificity of nucleotide excision repair allows it to effectively handle a wide variety of DNA lesions, making it an essential part of the cellular response to DNA damage.