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. Fields of science natural sciencesearth and related environmental sciencesgeologymineralogycrystallographynatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsnatural sciencesphysical sciencesopticsmicroscopyelectron microscopynatural sciencesphysical sciencesopticsspectroscopyabsorption spectroscopynatural sciencesbiological sciencesmolecular biology Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2015-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF) Call for proposal H2020-MSCA-IF-2015 See other projects for this call Funding Scheme MSCA-IF-EF-ST - Standard EF Coordinator INSTITUTE OF SCIENCE AND TECHNOLOGY AUSTRIA Net EU contribution € 178 156,80 Address Am Campus 1 3400 Klosterneuburg Austria See on map Region Ostösterreich Niederösterreich Wiener Umland/Nordteil Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 178 156,80