A multisubunit pore complex (400 kDa) in the outer mitochondrial membrane through which cytoplasmically synthesized proteins pass and are then transported by the TIM23 complex (translocase of the inner membrane) into either the matrix, inner membrane, or intermembrane space. The channel protein of the outer mitochondrial membrane is Tom40 (translocase of the outer mitochondrial membrane-40) which is tightly associated with the receptor protein Tom22 along with Tom7, Tom6, and Tom5. The receptor proteins Tom70 and Tom20 are more weakly associated and are involved in the recognition of preproteins. Precursors of signal-anchored proteins, however, appear not to be inserted via the general import pore.
Subjects: Medicine and Health.