InterPro domain: IPR007379

Tim44 is an essential component of the machinery that mediates the translocation of nuclear-encoded proteins across the mitochondrial inner membrane [ 1 ]. Tim44 is thought to bind phospholipids of the mitochondrial inner membrane both by electrostatic interactions and by penetrating the polar head group region [ 2 ]. This entry represents the C-terminal region of Tim44 that has been shown to form a stable proteolytic fragment in yeast. This region is also found in a set of smaller bacterial proteins. The molecular function of the bacterial members is unknown, but transport seems likely. The crystal structure of the C terminus of Tim44 has revealed a large hydrophobic pocket which might play an important role in interacting with the acyl chains of lipid molecules in the mitochondrial membrane [ 2 ].

1. Domain structure and lipid interaction of recombinant yeast Tim44. Proc. Natl. Acad. Sci. U.S.A. 96, 8890-4
2. Crystal structure of yeast mitochondrial peripheral membrane protein Tim44p C-terminal domain. J. Mol. Biol. 359, 798-804