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The preprotein translocation channel of the outer membrane of mitochondria

K P Künkele1, S Heins, M Dembowski

  • 1Institut für Physiologische Chemie, Physikalische Biochemie, und Zellbiologie der Universität München, Germany.

Cell
|July 11, 1998
PubMed

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Translocation of Proteins into the Mitochondria

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Sorting of outer membrane proteins:
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Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
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Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
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