Structural highlights
Function
[MUTS_ECOLI] This protein is involved in the repair of mismatches in DNA. It is possible that it carries out the mismatch recognition step. This protein has a weak ATPase activity. [MUTL_ECOLI] This protein is involved in the repair of mismatches in DNA. It is required for dam-dependent methyl-directed DNA mismatch repair. May act as a "molecular matchmaker", a protein that promotes the formation of a stable complex between two or more DNA-binding proteins in an ATP-dependent manner without itself being part of the final effector complex. The ATPase activity of MutL is stimulated by DNA.
Publication Abstract from PubMed
To avoid mutations in the genome, DNA replication is generally followed by DNA mismatch repair (MMR). MMR starts when a MutS homolog recognizes a mismatch and undergoes an ATP-dependent transformation to an elusive sliding clamp state. How this transient state promotes MutL homolog recruitment and activation of repair is unclear. Here we present a crystal structure of the MutS/MutL complex using a site-specifically crosslinked complex and examine how large conformational changes lead to activation of MutL. The structure captures MutS in the sliding clamp conformation, where tilting of the MutS subunits across each other pushes DNA into a new channel, and reorientation of the connector domain creates an interface for MutL with both MutS subunits. Our work explains how the sliding clamp promotes loading of MutL onto DNA, to activate downstream effectors. We thus elucidate a crucial mechanism that ensures that MMR is initiated only after detection of a DNA mismatch.
MutS/MutL crystal structure reveals that the MutS sliding clamp loads MutL onto DNA.,Groothuizen FS, Winkler I, Cristovao M, Fish A, Winterwerp HH, Reumer A, Marx AD, Hermans N, Nicholls RA, Murshudov GN, Lebbink JH, Friedhoff P, Sixma TK Elife. 2015 Jul 11;4. doi: 10.7554/eLife.06744. PMID:26163658[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Groothuizen FS, Winkler I, Cristovao M, Fish A, Winterwerp HH, Reumer A, Marx AD, Hermans N, Nicholls RA, Murshudov GN, Lebbink JH, Friedhoff P, Sixma TK. MutS/MutL crystal structure reveals that the MutS sliding clamp loads MutL onto DNA. Elife. 2015 Jul 11;4. doi: 10.7554/eLife.06744. PMID:26163658 doi:http://dx.doi.org/10.7554/eLife.06744
