title: Respiratory complex I: 'steam engine' of the cell?
abstract: Complex I is the first enzyme of the respiratory chain and plays a central role in cellular energy production. It has been implicated in many human neurodegenerative diseases, as well as in ageing. One of the biggest membrane protein complexes, it is an L-shaped assembly consisting of hydrophilic and membrane domains. Previously, we have determined structures of the hydrophilic domain in several redox states. Last year was marked by fascinating breakthroughs in the understanding of the complete structure. We described the architecture of the membrane domain and of the entire bacterial complex I. X-ray analysis of the larger mitochondrial enzyme has also been published. The core subunits of the bacterial and mitochondrial enzymes have remarkably similar structures. The proposed mechanism of coupling between electron transfer and proton translocation involves long-range conformational changes, coordinated in part by a long α-helix, akin to the coupling rod of a steam engine.
authors.affiliation: Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.
authors.forename: Rouslan G
authors.initials: RG
authors.lastname: Efremov
authors.forename: Leonid A
authors.initials: LA
authors.lastname: Sazanov
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002477:Cells / Q000166:cytology / Q000201:enzymology*; D042967:Electron Transport Complex I / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008928:Mitochondria / Q000201:enzymology; D017434:Protein Structure, Tertiary
chemical_list: D042967:Electron Transport Complex I