DNA REPAIR CONCEPTS

About this course

IntroductionBase excision repairNucleotide repairMismatch repairDouble standard repairApplicationsDNA ligation sticky endsBlunt endsrestricted endonuclease part1restricted endonuclease part2DNA repair definitionDNA 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 repairTomas 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 repair2.nucleotide excision repair3.Mismatch repair4.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.