Which of the following is NOT a step in mammalian nucleotide excision repair?

Question

Quizplus · Accepted Answer

The sugar-phosphate backbone is cut in two places during mammalian nucleotide excision repair. First, the damaged DNA strand is cut upstream of the lesion by the endonuclease complex consisting of XPF and ERCC1. Then, the strand is cut downstream of the lesion by the endonuclease XPG. The resulting gap is filled in by DNA polymerases, and the DNA backbone is closed with DNA ligase. Lesions are recognized by XPA protein, which is essential for the process. Therefore, choice B is the incorrect step.

Which of the Following Is NOT a Step in Mammalian