Architecture and assembly dynamics of the essential mitochondrial chaperone complex TIM9·10·12

Publikation: Bidrag til tidsskriftTidsskriftartikelfagfællebedømt

Tim chaperones transport membrane proteins to the two mitochondrial membranes. TIM9·10, a 70 kDa protein complex formed by 3 copies of Tim9 and Tim10, guides its clients across the aqueous compartment. The TIM9·10·12 complex is the anchor point at the inner-membrane insertase TIM22. The subunit composition of TIM9·10·12 remains debated. Joint NMR, small-angle X-ray scattering, and MD simulation data allow us to derive a structural model of the TIM9·10·12 assembly, with a 2:3:1 stoichiometry (Tim9:Tim10:Tim12). Both TIM9·10 and TIM9·10·12 hexamers are in a dynamic equilibrium with their constituent subunits, exchanging on a minutes timescale. NMR data establish that the subunits exhibit large conformational dynamics: when the conserved cysteines of the CX3C-Xn-CX3C motifs are formed, short α helices are formed, and these are fully stabilized only upon formation of the mature hexameric chaperone. We propose that the continuous subunit exchange allows mitochondria to control their level of inter-membrane space chaperones.

OriginalsprogEngelsk
TidsskriftStructure
Vol/bind29
Udgave nummer9
Sider (fra-til)1065-1073.e4
ISSN0969-2126
DOI
StatusUdgivet - 2021

Bibliografisk note

Funding Information:
We thank Aline Le Roy and Christine Ebel for excellent support with AUC experiments, and Nils Wiedemann, Caroline Lindau, Beate Bersch, and Vilius Kurauskas for insightful discussions, and Bernhard Brutscher, Alicia Vallet, and Adrien Favier for excellent NMR platform operation. This study was supported by the European Research Council (StG-2012-311318- ProtDyn2Function), the Agence Nationale de la Recherche (ANR-18-CE92-0032), and the Lundbeck Foundation BRAIN- STRUC initiative. This study used the platforms (NMR, EM, isotope-labeling) of the Grenoble Instruct-ERIC Center (ISBG; UMS 3518 CNRS-CEA-UJF-EMBL) with support from FRISBI (ANR-10-INSB-05-02) and GRAL (ANR-10-LABX-49-01) within the Grenoble Partnership for Structural Biology (PSB). The experiments were performed on beamline BM29 at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The simulations were performed on the Danish National Supercomputer for Life Sciences (Computerome). K.W. and P.S. designed and initiated the research project. K.W. and A.H. prepared all protein samples. K.W. and P.S. performed and analyzed NMR experiments. K.W. and M.B. performed and analyzed the SAXS data. Y.W. and K.L.-L. designed and performed the MD simulations. K.W. Y.W. and P.S. prepared the figures. P.S. wrote the paper with input from all authors. The authors declare that they have no competing interests.

Funding Information:
We thank Aline Le Roy and Christine Ebel for excellent support with AUC experiments, and Nils Wiedemann, Caroline Lindau, Beate Bersch, and Vilius Kurauskas for insightful discussions, and Bernhard Brutscher, Alicia Vallet, and Adrien Favier for excellent NMR platform operation. This study was supported by the European Research Council ( StG-2012-311318 - ProtDyn2Function), the Agence Nationale de la Recherche ( ANR-18-CE92-0032 ), and the Lundbeck Foundation BRAIN- STRUC initiative. This study used the platforms (NMR, EM, isotope-labeling) of the Grenoble Instruct-ERIC Center (ISBG; UMS 3518 CNRS-CEA-UJF-EMBL) with support from FRISBI ( ANR-10-INSB-05-02 ) and GRAL ( ANR-10-LABX-49-01 ) within the Grenoble Partnership for Structural Biology (PSB). The experiments were performed on beamline BM29 at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. The simulations were performed on the Danish National Supercomputer for Life Sciences (Computerome).

Publisher Copyright:
© 2021 Elsevier Ltd

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