Mismatch Repair, Watson Crick Base Pairs in a DNA Duplex, DNA Polymerase, Endonuclease Cleaves, DNA Segments, Homologous, Loop Formation

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	Mismatch Repair - Mismatch or non-Watson-Crick base pairs in a DNA duplex can arise through replication errors, through deamination of 5' methylcytosine in DNA to yield thymine or thorough recombination between DNA segments that are not completely homologous. If DNA polymerase introduces an incorrect nucleotide, this error is corrected by mismatch repair. Mismatch repair system scans newly replicated DNA or daughter strand and finds the mismatch errors or nucleotides.
It uses 3 proteins named Mut S, Mut H and Mut L for the repair. Mut S binds to the mismatch site and it waits there. Then Mut Land Mut H bind creating a loop starting from the site GATC to GATC. This loop formation is driven by the A TP. Then Mut H, which is assumed as endonuclease cleaves at the GA TC site on both the sides of the mismatch. Then Mut U unwinds the strand. Then DNA polymerase synthesizes the new strand and ligase joins the strand.