Functional Specifics of the MutL Protein of the DNA Mismatch Repair System in Different Organisms

A DNA mismatch repair (MMR) system is found in all living organisms. MMR dysfunction at any step of DNA repair leads to an accumulation of mutations in the cell, thus decreasing the viability. In most organisms, the MutL protein plays a key role in mismatch elimination. MutL is capable of introducing a single-strand break in the daughter DNA strand. The review summarizes information about the MMR systems of eukaryotes and prokaryotes, the MutL structure, and the interactions of MutL with DNA and other MMR proteins.