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Membrane protein insertion through a mitochondrial ?-barrel gate.

ABSTRACT: The biogenesis of mitochondria, chloroplasts, and Gram-negative bacteria requires the insertion of ?-barrel proteins into the outer membranes. Homologous Omp85 proteins are essential for membrane insertion of ?-barrel precursors. It is unknown if precursors are threaded through the Omp85-channel interior and exit laterally or if they are translocated into the membrane at the Omp85-lipid interface. We have mapped the interaction of a precursor in transit with the mitochondrial Omp85-channel Sam50 in the native membrane environment. The precursor is translocated into the channel interior, interacts with an internal loop, and inserts into the lateral gate by ?-signal exchange. Transport through the Omp85-channel interior followed by release through the lateral gate into the lipid phase may represent a basic mechanism for membrane insertion of ?-barrel proteins.

SUBMITTER: Hohr AIC

PROVIDER: S-EPMC5959003 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature

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Membrane protein insertion through a mitochondrial β-barrel gate.

Höhr Alexandra I C AIC Lindau Caroline C Wirth Christophe C Qiu Jian J Stroud David A DA Kutik Stephan S Guiard Bernard B Hunte Carola C Becker Thomas T Pfanner Nikolaus N Wiedemann Nils N

Science (New York, N.Y.) 20180101 6373

The biogenesis of mitochondria, chloroplasts, and Gram-negative bacteria requires the insertion of β-barrel proteins into the outer membranes. Homologous Omp85 proteins are essential for membrane insertion of β-barrel precursors. It is unknown if precursors are threaded through the Omp85-channel interior and exit laterally or if they are translocated into the membrane at the Omp85-lipid interface. We have mapped the interaction of a precursor in transit with the mitochondrial Omp85-channel Sam50 ...[more]

PMID: 29348211

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