Crystal structures of the apo form ((a) PDB ID: 1BKN) and ADPNP-bound form ((b) PDB ID: 1B63) of the E. coli MutL N-terminal domain. (c) A schematic representation of a model for the ATP-dependent conformational change of full-length [73]. NTD and CTD indicate the N-terminal ATPase domain and the C-terminal endonuclease domain, respectively. In the apo form of , the PMS2 and MLH1 subunits dimerize via their C-terminal domains. ATP binding induces the dimerization of the N-terminal domain and condensation of the molecule.
