title: The iron-sulfur core in Rieske proteins is not symmetric.
abstract: At variance with ferredoxins, Rieske-type proteins contain a chemically asymmetric iron-sulfur cluster. Nevertheless, X-ray crystallography apparently finds their [2Fe-2S] cores to be structurally symmetric or very close to symmetric (i.e. the four iron-sulfur bonds in the [2Fe-2S] core are equidistant). Using a combination of advanced density-based approaches, including finite-temperature molecular dynamics to access thermal fluctuations and free-energy profiles, in conjunction with correlated wavefunction-based methods we clearly predict an asymmetric core structure. This reveals a fundamental and intrinsic difference within the iron-sulfur clusters hosted by Rieske proteins and ferredoxins and thus opens up a new dimension for the ongoing efforts in understanding the role of Rieske-type [2Fe-2S] cluster in electron transfer processes that occur in almost all biological systems.
authors.affiliation: Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780, Bochum, Germany, ehesan.ali@theochem.rub.de.
authors.forename: Md Ehesan
authors.initials: ME
authors.lastname: Ali
authors.forename: Nisanth N
authors.initials: NN
authors.lastname: Nair
authors.forename: Marius
authors.initials: M
authors.lastname: Retegan
authors.forename: Frank
authors.initials: F
authors.lastname: Neese
authors.forename: Volker
authors.initials: V
authors.lastname: Staemmler
authors.forename: Dominik
authors.initials: D
authors.lastname: Marx
mesh_terms: D018360:Crystallography, X-Ray; D014450:Electron Transport Complex III / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008958:Models, Molecular; D013455:Sulfur / Q000737:chemistry*
chemical_list: C037989:Rieske iron-sulfur protein; D013455:Sulfur; D007501:Iron; D014450:Electron Transport Complex III