InterPro domain: IPR011184

Mismatch repair (MMR) is one of five major DNA repair pathways, the others being homologous recombination repair, non-homologous end joining, nucleotide excision repair, and base excision repair. The mismatch repair system recognises and repairs mispaired or unpaired nucleotides that result from errors in DNA replication. The most extensively studied general MMR system is the MutHLS pathway of the bacterium Escherichia coli. In the first step of the MutHLS pathway, the MutS protein (in the form of a dimer) binds to the site of a mismatch in double-stranded DNA. Through a complex interaction between MutS, MutL and MutH, a section of the newly replicated DNA strand (and thus the strand with the replication error) at the location of the mismatch bound by MutS is targeted for removal [ 1 ]. Homologues of MutS have been found in many species including eukaryotes, Archaea and other bacteria, and together these proteins have been grouped into the MutS family.

This entry represents a subset of the MutS family members, including Msh2. Msh2 (MutS homologue 2) has a dual role in DNA repair and apoptosis. Msh2 acts as a heterodimer with Msh6, which together function to recruit the Mlh (MutL homologue) - Pms (post-meiotic segregation) heterodimer, and to replace the mispaired base [ 2 ].

1. A phylogenomic study of the MutS family of proteins. Nucleic Acids Res. 26, 4291-300
2. DNA binding properties of the yeast Msh2-Msh6 and Mlh1-Pms1 heterodimers. Biol. Chem. 383, 969-75