Question

BER detects wrong bases by __________________

(a) Bulges produced in the DNA

(b) Strength of bond between the bases

(c) Flipping of bases

(d) Detected by RNA polymerase stalling

The question was posed to me in examination.

My doubt is from Repair of DNA Damage: MMR, BER in chapter DNA Mutation, DNA Repair, Transposable Elements of Cytogenetics

Answer 1

Right choice is (c) Flipping of bases

The explanation is: It has been seen that mis-incorporated bases have a tendency to appear flipped out, these flipped out bases are recognized by the BER. This is because flipping requires less energy than distortions like bulging. RNA pol stalling can trigger NER mainly TC-NER.