A common coupling mechanism for A-type heme-copper oxidases from bacteria to mitochondria
| Autor: | Andrew M. Hartley, Francis Haraux, Peter R. Rich, Naho Genko, Jing-Yang Xu, Amandine Maréchal, Brigitte Meunier |
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| Přispěvatelé: | Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Protéines et Systèmes Membranaires (LPSM), Département Biochimie, Biophysique et Biologie Structurale (B3S), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Intégrative de la Cellule (I2BC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Biogenèse et fonctionnement des complexes OXPHOS mitochondriaux (BIOMIT), Département Biologie Cellulaire (BioCell) |
| Rok vydání: | 2020 |
| Předmět: |
Mitochondrial DNA
Saccharomyces cerevisiae Proteins [SDV]Life Sciences [q-bio] Saccharomyces cerevisiae Heme macromolecular substances Mitochondrion bcs 010402 general chemistry Biochemistry 01 natural sciences Electron Transport Complex IV ADP/O ratio 03 medical and health sciences chemistry.chemical_compound cytochrome c oxidase H/e stoichiometry Cytochrome c oxidase Inner mitochondrial membrane 030304 developmental biology chemistry.chemical_classification 0303 health sciences Ion Transport Multidisciplinary Bacteria biology Mutagenesis Proton Pumps Biological Sciences biology.organism_classification Mitochondria 0104 chemical sciences Oxygen Enzyme chemistry Mitochondrial Membranes Biophysics biology.protein Protons Oxidoreductases proton pumping Oxidation-Reduction Copper |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America Proceedings of the National Academy of Sciences of the United States of America, 2020, ⟨10.1073/pnas.2001572117⟩ Proceedings of the National Academy of Sciences of the United States of America, National Academy of Sciences, 2020, ⟨10.1073/pnas.2001572117⟩ |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.2001572117 |
| Popis: | Significance We present a comprehensive investigation of mitochondrial DNA-encoded variants of cytochrome c oxidase (CcO) that harbor mutations within their core catalytic subunit I, designed to interrogate the presently disputed functions of the three putative proton channels. We assess overall respiratory competence, specific CcO catalytic activity, and, most importantly, proton/electron (H+/e−) stoichiometry from adenosine diphosphate to oxygen ratio measurements on preparations of intact mitochondria. We unequivocally show that yeast mitochondrial CcO uses the D-channel to translocate protons across its hydrophilic core, providing direct evidence in support of a common proton pumping mechanism across all members of the A-type heme-copper oxidase superfamily, independent of their bacterial or mitochondrial origin. Mitochondria metabolize almost all the oxygen that we consume, reducing it to water by cytochrome c oxidase (CcO). CcO maximizes energy capture into the protonmotive force by pumping protons across the mitochondrial inner membrane. Forty years after the H+/e− stoichiometry was established, a consensus has yet to be reached on the route taken by pumped protons to traverse CcO’s hydrophobic core and on whether bacterial and mitochondrial CcOs operate via the same coupling mechanism. To resolve this, we exploited the unique amenability to mitochondrial DNA mutagenesis of the yeast Saccharomyces cerevisiae to introduce single point mutations in the hydrophilic pathways of CcO to test function. From adenosine diphosphate to oxygen ratio measurements on preparations of intact mitochondria, we definitely established that the D-channel, and not the H-channel, is the proton pump of the yeast mitochondrial enzyme, supporting an identical coupling mechanism in all forms of the enzyme. |
| Databáze: | OpenAIRE |
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