title: The multitude of iron-sulfur clusters in respiratory complex I.
abstract: Respiratory complex I couples the electron transfer from NADH to ubiquinone with the translocation of protons across the membrane. Complex I contains one non-covalently bound flavin mononucleotide and, depending on the species, up to ten iron-sulfur (Fe/S) clusters as cofactors. The reason for the presence of the multitude of Fe/S clusters in complex I remained enigmatic for a long time. The question was partly answered by investigations on the evolution of the complex revealing the stepwise construction of the electron transfer domain from several modules. Extension of the ancestral to the modern electron input domain was associated with the acquisition of several Fe/S-proteins. The X-ray structure of the complex showed that the NADH oxidation-site is connected with the quinone-reduction site by a chain of seven Fe/S-clusters. Fast enzyme kinetics revealed that this chain of Fe/S-clusters is used to regulate electron-tunneling rates within the complex. A possible function of the off-pathway cluster N1a is discussed. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
authors.affiliation: Albert-Ludwigs-Universität Freiburg, Institut für Biochemie, Albertstr. 21, 79104 Freiburg i. Br., Germany.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Gnandt
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, CFEL, Notkestr. 85, Hamburg, Germany.
authors.forename: Katerina
authors.initials: K
authors.lastname: Dörner
authors.affiliation: Delft University of Technology, Department of Biotechnology, Julianalaan 67, 2628 BC Delft, The Netherlands.
authors.forename: Marc F J
authors.initials: MFJ
authors.lastname: Strampraad
authors.affiliation: Delft University of Technology, Department of Biotechnology, Julianalaan 67, 2628 BC Delft, The Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: de Vries
authors.affiliation: Albert-Ludwigs-Universität Freiburg, Institut für Biochemie, Albertstr. 21, 79104 Freiburg i. Br., Germany. Electronic address: friedrich@bio.chemie.uni-freiburg.de.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Friedrich
mesh_terms: D004579:Electron Transport; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D055503:Protein Multimerization; D011522:Protons; D011808:Quinone Reductases / Q000235:genetics / Q000378:metabolism; D014451:Ubiquinone / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; C000596778:NuoCD protein, E coli; D011522:Protons; D009243:NAD; D014451:Ubiquinone; C502197:NuoF protein, E coli; D011808:Quinone Reductases; C480162:NuoB protein, E coli; C556263:NuoE protein, E coli; C556264:NuoG protein, E coli; D042967:Electron Transport Complex I
keywords: Biological electron transfer; Complex I; EPR-spectroscopy; Iron–sulfur cluster; NADH dehydrogenase