Journal article

Membrane protein insertion through a mitochondrial beta-barrel gate

Alexandra IC Hohr, Caroline Lindau, Christophe Wirth, Jian Qiu, David A Stroud, Stephan Kutik, Bernard Guiard, Carola Hunte, Thomas Becker, Nikolaus Pfanner, Nils Wiedemann



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 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 β-signal exchange. Transport through..

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University of Melbourne Researchers


Awarded by European Research Council

Awarded by Deutsche Forschungsgemeinschaft

Awarded by Sonderforschungsbereiche grants

Awarded by Excellence Initiative of the German federal and state governments grants

Funding Acknowledgements

We thank C. Meisinger for discussion. This work was supported by the European Research Council Consolidator Grant no. 648235, the Deutsche Forschungsgemeinschaft grants PF 202/8-1 and BE 4679/2-1, the Sonderforschungsbereiche grants 746 and 1140, and the Excellence Initiative of the German federal and state governments grants EXC 294 BIOSS and GSC-4 Spemann Graduate School). Work included in this study has also been performed in partial fulfillment of the requirements for the doctoral theses of A.I.C.H. and C.L. and the diploma thesis of A.I.C.H. at the University of Freiburg. The data presented in this paper are tabulated in the main paper and the supplementary materials.