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Updated: Jul 9, 2026

Isolation and Functional Analysis of Mitochondria from Cultured Cells and Mouse Tissue
Published on: March 23, 2015
The protein import motor of mitochondria
Walter Neupert1, Michael Brunner
1Institut für Physiologische Chemie, Universität München, Butenandtstrabetae 5, Gebäude B, D-81377 Munich, Germany. neupert@bio.med.uni-muenchen.de
Abstract:
Proteins that are destined for the matrix of mitochondria are transported into this organelle by two translocases: the TOM complex, which transports proteins across the outer mitochondrial membrane; and the TIM23 complex, which gets them through the inner mitochondrial membrane. Two models have been proposed to explain how this protein-import machinery works -- a targeted Brownian ratchet, in which random motion is translated into vectorial motion, or a 'power stroke', which is exerted by a component of the import machinery. Here, we review the data for and against each model.
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