Central receptor component of the translocase of the outer membrane of mitochondria (TOM complex) responsible for the recognition and translocation of cytosolically synthesized mitochondrial preproteins. Together with the peripheral receptor TOM20 functions as the transit peptide receptor and facilitates the movement of preproteins into the translocation pore (PubMed:10982837). Required for the translocation across the mitochondrial outer membrane of cytochrome P450 monooxygenases (By similarity).
