Tom40 is the channel-forming subunit of the translocase of the mitochondrial outer
membrane (TOM complex), essential for protein import into mitochondria. Tom40 is
synthesized in the cytosol and contains information for its mitochondrial targeting and
assembly. A number of stable import intermediates have been identified for Tom40
precursors in fungi, the first being an association with the sorting and assembly machinery
(SAM) of the outer membrane. By examining the import pathway of human Tom40, we have …