Which DNA repair mechanism recognizes a distortion in double helix geometry caused by DNA polymerase's insertion of an incorrect nucleotide during replication, one that escaped the enzyme's proofreading exonuclease?
A)nucleotide excision repair
B)base excision repair
C)mismatch repair
D)double-strand breakage repair
E)transcription-coupled pathway

Question

Quizplus · Accepted Answer

Mismatch repair is the DNA repair mechanism that recognizes a distortion in double helix geometry caused by DNA polymerase's insertion of an incorrect nucleotide during replication, one that escaped the enzyme's proofreading exonuclease. Mismatch repair can distinguish the newly synthesized strand from the parental strand and selectively remove and replace the mispaired nucleotide. Nucleotide excision repair deals with larger lesions caused by environmental factors like UV radiation, while base excision repair deals with smaller lesions caused by chemical modifications to individual bases. Double-strand breakage repair and transcription-coupled pathways are not directly related to the issue of misincorporated nucleotides during replication.

Which DNA Repair Mechanism Recognizes a Distortion in Double Helix