H2020Individual fellowship2016–2018

RSC · Atomic Resolution Structures of Mitochondrial Respiratory Chain Supercomplexes

Horizon 2020 — Marie Skłodowska-Curie Actions

Duration
2016-09-01 → 2018-08-31
EU contribution
€178,157
Participants
1
Scheme
MSCA-IF

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Results in brief

Atomic Resolution Structures of Mitochondrial Respiratory Chain Supercomplexes

We are trying to understand the regulation and function of the mitochondrial electron transport chain, a series of large membrane protein complexes that are central to our metabolism. These complexes form into supercomplexes the function of which are unclear. We are solving the structures of these supercomplexes in order to get a better understanding of their role in metabolism. Defects of the mitochondrial electron transport chain cause severe neuro-degenerative diseases and high-resolution structures of the supercomplexes will help us to better understand the disease mechanisms and may lead to new therapies. The overall objectives of the project are to get high resolution structures of the mitochondrial electron transport chain complexes that will give us insight into the mechanism of the individual complexes and how they work together. We also hope to get insight into how malfunctioning of the complexes lead to disease.

Data: CORDIS, © European Union

Project objective

The objectives of this proposal are to determine atomic-resolution structures of mammalian mitochondrial respiratory chain supercomplexes (RCSs) by single particle electron cryo-microscopy (cryo-EM). It has been shown that the large protein complexes of the inner mitochondrial membrane responsible for electron transport from NADH to molecular oxygen (complexes I, III and IV) associate to form three major RCSs: I/III2, III2/IV2 and I/III2/IV. Currently, the physiological role of the RSCs is controversial and poorly understood. Atomic-resolution structures of the RSCs will be essential for fully understanding their physiology. Presently I have generated a 15 Å cryo-EM density map for RCS I/III2/IV from ~10,000 particles purified from Ovis aries mitochondria. Our preliminary data show that in order to push the resolution we will need to improve both the biochemical preparation of the RCS particles as well as the cryo-EM grid preparation. This will be done through systematic biochemical characterisation of the RCSs in different non-disruptive detergents and systematic grid preparation varying grid type and blotting conditions. In addition to RCS I/III2/IV, the structure of RCS I/III2 will be determined. High-resolution cryo-EM data will be collected at the Vienna Biocenter using the FEI Polara 300 mV microscope with Gatan K2 direct electron detector. In order to fully compare the make-up of the different RCSs mass spectrometric analysis will be carried out on the purified samples by our collaborators at the Laboratory for Molecular Biology (LMB). My previous experience in the laboratory of Dr Roderick MacKinnon mainly focused on membrane protein structure determination by X-ray crystallography and NMR spectroscopy. The opportunity to work at the IST Austria with Dr Leonid Sazanov will allow me to learn state of the art cryo-EM techniques, which are positioned to be the future of atomic-resolution structure determination for large macromolecular assemblies.

Original text from CORDIS.

Participants

  • INSTITUTE OF SCIENCE AND TECHNOLOGY AUSTRIA · KlosterneuburgCoordinatorAustria

Links

Data: CORDIS, © European Union