Question

What mechanism reduces the error rate in DNA replication from 1 mistake in 10⁵ bp replicated to 1 mistake in 10⁷ bp replicated?

Group of answer choices

a) proofreading of the exonuclease active site in DNA polymerase

b) mismatches are never repaired in DNA

c) neither, the error rate is less than 1 mistake in 10 billion base pairs due to the excellent activity of the catalytic site in DNA polymerase

d) DNA mismatch repair using MutS and Muth proteins

Answer 1

Ans: proofreading of the exonuclease active site in DNA polymerase.

Explanation:  The proofreading mechanism, by which correcting of any error or damages, in process of DNA replication, in immune response system, enzyme substrate activities and many other process.

The DNA polymerase l, ll, and lll have 3'-5' endonuclease activities by using the proofreading mechanism. During replication process, if any incorrect or mismatch base pair recognised, then DNA polymerase reverse it directions and cut the mismatch or error nucleotides. After this DNA polymerase reinsert the correct nucleotides base pair and continue the replication process. Proofreading have also importantimportant role in protein translation process.