DNA REPAIR CONCEPTS

Introduction

Base excision repair

Nucleotide repair

Mismatch repair

Double standard repair

Applications

DNA ligation sticky ends

Blunt ends

restricted endonuclease part1

restricted endonuclease part2

DNA repair definition

DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome.

Who discovered DNA repair

Tomas Lindahl, Paul Modrich and Aziz Sancar are awarded the Nobel Prize in Chemistry 2015 for having mapped and explained how the cell repairs its DNA and safeguards the genetic information.

Damaged to DNA caused by replication errors or mutations may have serious consequences.

The cell possesses an inbuilt system to repair the damaged DNA .

This may be achieved by 4 distinct mechanisms.

1.Base excision repair

2.nucleotide excision repair

3.Mismatch repair

4.Double strand break repair.

Base Excision Repair  is a repair mechanism that corrects damaged DNA by identifying damaged bases and replacing damaged bases with the correct nucleotide.

The correct nucleotide can be identified by referencing the complementary strand in the DNA pair based on the Watson-Crick DNA base pairing.

DNA bases are constantly subjected to damages like deamination or alkylation. The damaged base is often called the "A basic Site" or "AP site".

Damaged bases are first identified by DNA glycosylases. DNA glycosylases are enzymes that are capable of detecting initial lesions of DNA.

you can find more details in presentation slides.