3kdk | pdb_00003kdk
Structure of the C-terminal domain of Bacillus subtilis MutL bound to Zn2+
Structural highlights
Function[MUTL_BACSU] 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 a final effector complex (By similarity). Overexpression of mutSL partially suppresses the high spontaneous mutation frequency of a ytkD/mutM/yfhQ triple disruption which lacks the system required to prevent damage by oxidized guanine (8-oxo-dGTP). This suggests that MutSL also functions to repair mismatches due to oxidative stress in both growing and stationary phase cells.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDNA mismatch repair corrects errors that have escaped polymerase proofreading, increasing replication fidelity 100- to 1000-fold in organisms ranging from bacteria to humans. The MutL protein plays a central role in mismatch repair by coordinating multiple protein-protein interactions that signal strand removal upon mismatch recognition by MutS. Here we report the crystal structure of the endonuclease domain of Bacillus subtilis MutL. The structure is organized in dimerization and regulatory subdomains connected by a helical lever spanning the conserved endonuclease motif. Additional conserved motifs cluster around the lever and define a Zn(2+)-binding site that is critical for MutL function in vivo. The structure unveils a powerful inhibitory mechanism to prevent undesired nicking of newly replicated DNA and allows us to propose a model describing how the interaction with MutS and the processivity clamp could license the endonuclease activity of MutL. The structure also provides a molecular framework to propose and test additional roles of MutL in mismatch repair. Structure of the endonuclease domain of MutL: unlicensed to cut.,Pillon MC, Lorenowicz JJ, Uckelmann M, Klocko AD, Mitchell RR, Chung YS, Modrich P, Walker GC, Simmons LA, Friedhoff P, Guarne A Mol Cell. 2010 Jul 9;39(1):145-51. PMID:20603082[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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