The inner membrane of mitochondria contains a protein complex (MIM complex) that functions as a part of the preprotein import machinery. Five proteins have been identified so far. MIM23 and MIM17 are integral membrane proteins found in close proximity to preproteins at the early stages of import. In addition, in the MIM complex are two novel proteins, MIM33 and WM14. On the inner face of the inner membrane, the complex is associated to MIM44. MIM44 recruits mt-Hsp70, interacting in a sequential manner, regulated by ATP, with incoming segments of unfolded preproteins and facilitating its unidirectional translocation across the mitochondrial membranes.
The objetive of this project is twofold. First, the purification and clonning of MIM33 and MIM14 to characterize the function of those new components. Second, the purification and reconstitution in lipid bilayers of the native MIM complex to analyze the electrophysiological properties of the putative import channel.