Structural basis for energy transduction by respiratory alternative complex III

  • Electron transfer in respiratory chains generates the electrochemical potential that serves as energy source for the cell. Prokaryotes can use a wide range of electron donors and acceptors and may have alternative complexes performing the same catalytic reactions as the mitochondrial complexes. This is the case for the alternative complex III (ACIII), a quinol:cytochrome c/HiPIP oxidoreductase. In order to understand the catalytic mechanism of this respiratory enzyme, we determined the structure of ACIII from Rhodothermus marinus at 3.9 Å resolution by single-particle cryo-electron microscopy. ACIII presents a so-far unique structure, for which we establish the arrangement of the cofactors (four iron–sulfur clusters and six c-type hemes) and propose the location of the quinol-binding site and the presence of two putative proton pathways in the membrane. Altogether, this structure provides insights into a mechanism for energy transduction and introduces ACIII as a redox-driven proton pump.
Author:Joana Sofia de Sousa, Filipa Calisto, Julian David Langer, Deryck J. Mills, Patrícia N. Refojo, Miguel Teixeira, Werner Kühlbrandt, Janet Vonck, Manuela Pereira
Pubmed Id:
Parent Title (English):Nature Communications
Publisher:Nature Publishing Group UK
Place of publication:[London]
Document Type:Article
Year of Completion:2018
Date of first Publication:2018/04/30
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2018/06/14
Tag:Bioenergetics; Cryoelectron microscopy; Oxidoreductases
Issue:1, Art. 1728
Page Number:10
First Page:1
Last Page:10
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Institutes:Biochemie, Chemie und Pharmazie / Biochemie und Chemie
Angeschlossene und kooperierende Institutionen / MPI für Biophysik
Angeschlossene und kooperierende Institutionen / MPI für Hirnforschung
Dewey Decimal Classification:6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit
Licence (German):License LogoCreative Commons - Namensnennung 4.0