title: Interaction of complexes I, III, and IV within the bovine respirasome by single particle cryoelectron tomography.
abstract: The respirasome is a multisubunit supercomplex of the respiratory chain in mitochondria. Here we report the 3D reconstruction of the bovine heart respirasome, composed of dimeric complex III and single copies of complex I and IV, at about 2.2-nm resolution, determined by cryoelectron tomography and subvolume averaging. Fitting of X-ray structures of single complexes I, III(2), and IV with high fidelity allows interpretation of the model at the level of secondary structures and shows how the individual complexes interact within the respirasome. Surprisingly, the distance between cytochrome c binding sites of complexes III(2) and IV is about 10 nm. Modeling indicates a loose interaction between the three complexes and provides evidence that lipids are gluing them at the interfaces.
authors.affiliation: Electron Microscopy Group, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 7, 9747AG Groningen, The Netherlands.
authors.forename: Natalya V
authors.initials: NV
authors.lastname: Dudkina
authors.forename: Mikhail
authors.initials: M
authors.lastname: Kudryashev
authors.forename: Henning
authors.initials: H
authors.lastname: Stahlberg
authors.forename: Egbert J
authors.initials: EJ
authors.lastname: Boekema
mesh_terms: D000818:Animals; D002417:Cattle; D020285:Cryoelectron Microscopy; D004579:Electron Transport; D045222:Electron Transport Chain Complex Proteins / Q000378:metabolism* / Q000648:ultrastructure; D042967:Electron Transport Complex I / Q000378:metabolism / Q000648:ultrastructure; D014450:Electron Transport Complex III / Q000378:metabolism / Q000648:ultrastructure; D003576:Electron Transport Complex IV / Q000378:metabolism / Q000648:ultrastructure; D008928:Mitochondria / Q000378:metabolism* / Q000648:ultrastructure*; D008958:Models, Molecular; D011485:Protein Binding; D014054:Tomography / Q000379:methods*
chemical_list: D045222:Electron Transport Chain Complex Proteins; D003576:Electron Transport Complex IV; D042967:Electron Transport Complex I; D014450:Electron Transport Complex III