InterPro domain: IPR042120

The protein MutL is essential in mismatch repair as it coordinating multiple protein-protein interactions that signal strand removal upon mismatch recognition by MutS. MutL is composed of two structurally conserved domains connected by a variable flexible linker: an N-terminal ATPase domain and C-terminal dimerisation domain [ 1 ]. The latter harbours the the endonuclease activity of the protein. Structural studies have shown that this C-terminal region is organized into a dimerization and a regulatory subdomain connected by a helical lever spanning the conserved endonuclease motif.

This superfamily represents the dimerization subdomain of the C-terminal domain of the MutL protein which presents a Zn2+ binding site and is important for the mismatch repair function of MutL [ 2 ].

1. Structure of the MutL C-terminal domain: a model of intact MutL and its roles in mismatch repair. EMBO J. 23, 4134-45
2. Structure of the endonuclease domain of MutL: unlicensed to cut. Mol. Cell 39, 145-51