Replication associated nuclear DNA mismatch repair across kingdoms

The mismatch repair (MMR) system is an essential DNA repair mechanism that recognizes and corrects single base-base mismatches and unpaired nucleotides that escaped the proofreading exonuclease activity of DNA polymerases or recombination intermediates. This pathway is highly conserved throughout evolution. However, the nature and number of MMR proteins differ between eukaryotes and prokaryotes. Even more, the plant MMR system contains an ancient duplicated MMR protein. In addition, developmental processes vary among eukaryotic organisms. One striking feature is plant genome stability maintenance over multiple generations because embryogenesis and seed development occur after many divisions during plant vegetative growth. Thus, it was of our interest to review the present state of knowledge with respect to the MMR mechanism from eukaryotic organisms, with special comparisons between human, yeast, and plant systems.