1
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Jarman OD, Hirst J. Membrane-domain mutations in respiratory complex I impede catalysis but do not uncouple proton pumping from ubiquinone reduction. PNAS NEXUS 2022; 1:pgac276. [PMID: 36712358 PMCID: PMC9802314 DOI: 10.1093/pnasnexus/pgac276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 12/01/2022] [Indexed: 12/05/2022]
Abstract
Respiratory complex I [NADH:ubiquinone (UQ) oxidoreductase] captures the free energy released from NADH oxidation and UQ reduction to pump four protons across an energy-transducing membrane and power ATP synthesis. Mechanisms for long-range energy coupling in complex I have been proposed from structural data but not yet evaluated by robust biophysical and biochemical analyses. Here, we use the powerful bacterial model system Paracoccus denitrificans to investigate 14 mutations of key residues in the membrane-domain Nqo13/ND4 subunit, defining the rates and reversibility of catalysis and the number of protons pumped per NADH oxidized. We reveal new insights into the roles of highly conserved charged residues in lateral energy transduction, confirm the purely structural role of the Nqo12/ND5 transverse helix, and evaluate a proposed hydrated channel for proton uptake. Importantly, even when catalysis is compromised the enzyme remains strictly coupled (four protons are pumped per NADH oxidized), providing no evidence for escape cycles that circumvent blocked proton-pumping steps.
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Affiliation(s)
- Owen D Jarman
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
| | - Judy Hirst
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge CB2 0XY, UK
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2
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Respiratory complex I with charge symmetry in the membrane arm pumps protons. Proc Natl Acad Sci U S A 2022; 119:e2123090119. [PMID: 35759670 PMCID: PMC9271201 DOI: 10.1073/pnas.2123090119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Respiratory complex I is a central enzyme of cellular energy metabolism coupling quinone reduction with proton translocation. Its mechanism, especially concerning proton translocation, remains enigmatic. Three homologous subunits that contain a conserved pattern of charged and polar amino acid residues catalyze proton translocation. Strikingly, the central subunit NuoM contains a conserved glutamate residue at a position where conserved lysine residues are found in the other two subunits, resulting in a charge asymmetry discussed to be essential for proton translocation. We found that the respective glutamate to lysine mutation in Escherichia coli complex I lowers the amount of protons translocated per electron transferred by one-quarter. These data clarify the discussion about possible mechanisms of proton translocation by complex I. Energy-converting NADH:ubiquinone oxidoreductase, respiratory complex I, is essential for cellular energy metabolism coupling NADH oxidation to proton translocation. The mechanism of proton translocation by complex I is still under debate. Its membrane arm contains an unusual central axis of polar and charged amino acid residues connecting the quinone binding site with the antiporter-type subunits NuoL, NuoM, and NuoN, proposed to catalyze proton translocation. Quinone chemistry probably causes conformational changes and electrostatic interactions that are propagated through these subunits by a conserved pattern of predominantly lysine, histidine, and glutamate residues. These conserved residues are thought to transfer protons along and across the membrane arm. The distinct charge distribution in the membrane arm is a prerequisite for proton translocation. Remarkably, the central subunit NuoM contains a conserved glutamate residue in a position that is taken by a lysine residue in the two other antiporter-type subunits. It was proposed that this charge asymmetry is essential for proton translocation, as it should enable NuoM to operate asynchronously with NuoL and NuoN. Accordingly, we exchanged the conserved glutamate in NuoM for a lysine residue, introducing charge symmetry in the membrane arm. The stably assembled variant pumps protons across the membrane, but with a diminished H+/e− stoichiometry of 1.5. Thus, charge asymmetry is not essential for proton translocation by complex I, casting doubts on the suggestion of an asynchronous operation of NuoL, NuoM, and NuoN. Furthermore, our data emphasize the importance of a balanced charge distribution in the protein for directional proton transfer.
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3
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Cloning and Organelle Expression of Bamboo Mitochondrial Complex I Subunits Nad1, Nad2, Nad4, and Nad5 in the Yeast Saccharomyces cerevisiae. Int J Mol Sci 2022; 23:ijms23074054. [PMID: 35409414 PMCID: PMC8999482 DOI: 10.3390/ijms23074054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/02/2022] [Accepted: 04/04/2022] [Indexed: 02/04/2023] Open
Abstract
Mitochondrial respiratory complex I catalyzes electron transfer from NADH to ubiquinone and pumps protons from the matrix into the intermembrane space. In particular, the complex I subunits Nad1, Nad2, Nad4, and Nad5, which are encoded by the nad1, nad2, nad4, and nad5 genes, reside at the mitochondrial inner membrane and possibly function as proton (H+) and ion translocators. To understand the individual functional roles of the Nad1, Nad2, Nad4, and Nad5 subunits in bamboo, each cDNA of these four genes was cloned into the pYES2 vector and expressed in the mitochondria of the yeast Saccharomyces cerevisiae. The mitochondrial targeting peptide mt gene (encoding MT) and the egfp marker gene (encoding enhanced green fluorescent protein, EGFP) were fused at the 5'-terminal and 3'-terminal ends, respectively. The constructed plasmids were then transformed into yeast. RNA transcripts and fusion protein expression were observed in the yeast transformants. Mitochondrial localizations of the MT-Nad1-EGFP, MT-Nad2-EGFP, MT-Nad4-EGFP, and MT-Nad5-EGFP fusion proteins were confirmed by fluorescence microscopy. The ectopically expressed bamboo subunits Nad1, Nad2, Nad4, and Nad5 may function in ion translocation, which was confirmed by growth phenotype assays with the addition of different concentrations of K+, Na+, or H+.
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4
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Van den Bergh B, Schramke H, Michiels JE, Kimkes TEP, Radzikowski JL, Schimpf J, Vedelaar SR, Burschel S, Dewachter L, Lončar N, Schmidt A, Meijer T, Fauvart M, Friedrich T, Michiels J, Heinemann M. Mutations in respiratory complex I promote antibiotic persistence through alterations in intracellular acidity and protein synthesis. Nat Commun 2022; 13:546. [PMID: 35087069 PMCID: PMC8795404 DOI: 10.1038/s41467-022-28141-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 01/04/2022] [Indexed: 11/28/2022] Open
Abstract
Antibiotic persistence describes the presence of phenotypic variants within an isogenic bacterial population that are transiently tolerant to antibiotic treatment. Perturbations of metabolic homeostasis can promote antibiotic persistence, but the precise mechanisms are not well understood. Here, we use laboratory evolution, population-wide sequencing and biochemical characterizations to identify mutations in respiratory complex I and discover how they promote persistence in Escherichia coli. We show that persistence-inducing perturbations of metabolic homeostasis are associated with cytoplasmic acidification. Such cytoplasmic acidification is further strengthened by compromised proton pumping in the complex I mutants. While RpoS regulon activation induces persistence in the wild type, the aggravated cytoplasmic acidification in the complex I mutants leads to increased persistence via global shutdown of protein synthesis. Thus, we propose that cytoplasmic acidification, amplified by a compromised complex I, can act as a signaling hub for perturbed metabolic homeostasis in antibiotic persisters.
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Affiliation(s)
- Bram Van den Bergh
- Centre of Microbial and Plant Genetics, Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, VIB, Leuven, Belgium
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Hannah Schramke
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, The Netherlands
| | - Joran Elie Michiels
- Centre of Microbial and Plant Genetics, Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, VIB, Leuven, Belgium
| | - Tom E P Kimkes
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, The Netherlands
| | - Jakub Leszek Radzikowski
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, The Netherlands
| | - Johannes Schimpf
- Molecular Bioenergetics, Institute of Biochemistry, Albert-Ludwigs-University of Freiburg, Freiburg im Breisgau, Germany
| | - Silke R Vedelaar
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, The Netherlands
| | - Sabrina Burschel
- Molecular Bioenergetics, Institute of Biochemistry, Albert-Ludwigs-University of Freiburg, Freiburg im Breisgau, Germany
| | - Liselot Dewachter
- Centre of Microbial and Plant Genetics, Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, VIB, Leuven, Belgium
| | - Nikola Lončar
- Molecular Enzymology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, The Netherlands
| | - Alexander Schmidt
- Proteomics Core Facility, Biozentrum, University of Basel, Basel, Switzerland
| | - Tim Meijer
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, The Netherlands
| | - Maarten Fauvart
- Centre of Microbial and Plant Genetics, Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium
- Center for Microbiology, Flanders Institute for Biotechnology, VIB, Leuven, Belgium
- imec, Leuven, Belgium
| | - Thorsten Friedrich
- Molecular Bioenergetics, Institute of Biochemistry, Albert-Ludwigs-University of Freiburg, Freiburg im Breisgau, Germany
| | - Jan Michiels
- Centre of Microbial and Plant Genetics, Department of Molecular and Microbial Systems, KU Leuven, Leuven, Belgium.
- Center for Microbiology, Flanders Institute for Biotechnology, VIB, Leuven, Belgium.
| | - Matthias Heinemann
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, The Netherlands.
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5
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Kolata P, Efremov RG. Structure of Escherichia coli respiratory complex I reconstituted into lipid nanodiscs reveals an uncoupled conformation. eLife 2021; 10:e68710. [PMID: 34308841 PMCID: PMC8357420 DOI: 10.7554/elife.68710] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/23/2021] [Indexed: 01/22/2023] Open
Abstract
Respiratory complex I is a multi-subunit membrane protein complex that reversibly couples NADH oxidation and ubiquinone reduction with proton translocation against transmembrane potential. Complex I from Escherichia coli is among the best functionally characterized complexes, but its structure remains unknown, hindering further studies to understand the enzyme coupling mechanism. Here, we describe the single particle cryo-electron microscopy (cryo-EM) structure of the entire catalytically active E. coli complex I reconstituted into lipid nanodiscs. The structure of this mesophilic bacterial complex I displays highly dynamic connection between the peripheral and membrane domains. The peripheral domain assembly is stabilized by unique terminal extensions and an insertion loop. The membrane domain structure reveals novel dynamic features. Unusual conformation of the conserved interface between the peripheral and membrane domains suggests an uncoupled conformation of the complex. Considering constraints imposed by the structural data, we suggest a new simple hypothetical coupling mechanism for the molecular machine.
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Affiliation(s)
- Piotr Kolata
- Center for Structural Biology, Vlaams Instituut voor BiotechnologieBrusselsBelgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit BrusselBrusselsBelgium
| | - Rouslan G Efremov
- Center for Structural Biology, Vlaams Instituut voor BiotechnologieBrusselsBelgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit BrusselBrusselsBelgium
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6
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Biochemical consequences of two clinically relevant ND-gene mutations in Escherichia coli respiratory complex I. Sci Rep 2021; 11:12641. [PMID: 34135385 PMCID: PMC8209014 DOI: 10.1038/s41598-021-91631-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 05/28/2021] [Indexed: 11/28/2022] Open
Abstract
NADH:ubiquinone oxidoreductase (respiratory complex I) plays a major role in energy metabolism by coupling electron transfer from NADH to quinone with proton translocation across the membrane. Complex I deficiencies were found to be the most common source of human mitochondrial dysfunction that manifest in a wide variety of neurodegenerative diseases. Seven subunits of human complex I are encoded by mitochondrial DNA (mtDNA) that carry an unexpectedly large number of mutations discovered in mitochondria from patients’ tissues. However, whether or how these genetic aberrations affect complex I at a molecular level is unknown. Here, we used Escherichia coli as a model system to biochemically characterize two mutations that were found in mtDNA of patients. The V253AMT-ND5 mutation completely disturbed the assembly of complex I, while the mutation D199GMT-ND1 led to the assembly of a stable complex capable to catalyze redox-driven proton translocation. However, the latter mutation perturbs quinone reduction leading to a diminished activity. D199MT-ND1 is part of a cluster of charged amino acid residues that are suggested to be important for efficient coupling of quinone reduction and proton translocation. A mechanism considering the role of D199MT-ND1 for energy conservation in complex I is discussed.
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7
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Zhang F, Vik SB. Analysis of the assembly pathway for membrane subunits of Complex I reveals that subunit L (ND5) can assemble last in E. coli. BBA ADVANCES 2021; 1. [DOI: 10.1016/j.bbadva.2021.100027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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8
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Kampjut D, Sazanov LA. The coupling mechanism of mammalian respiratory complex I. Science 2020; 370:science.abc4209. [PMID: 32972993 DOI: 10.1126/science.abc4209] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 09/08/2020] [Indexed: 12/16/2022]
Abstract
Mitochondrial complex I couples NADH:ubiquinone oxidoreduction to proton pumping by an unknown mechanism. Here, we present cryo-electron microscopy structures of ovine complex I in five different conditions, including turnover, at resolutions up to 2.3 to 2.5 angstroms. Resolved water molecules allowed us to experimentally define the proton translocation pathways. Quinone binds at three positions along the quinone cavity, as does the inhibitor rotenone that also binds within subunit ND4. Dramatic conformational changes around the quinone cavity couple the redox reaction to proton translocation during open-to-closed state transitions of the enzyme. In the induced deactive state, the open conformation is arrested by the ND6 subunit. We propose a detailed molecular coupling mechanism of complex I, which is an unexpected combination of conformational changes and electrostatic interactions.
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Affiliation(s)
- Domen Kampjut
- IST Austria, Am Campus 1, 3400 Klosterneuburg, Austria
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9
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Maldonado M, Padavannil A, Zhou L, Guo F, Letts JA. Atomic structure of a mitochondrial complex I intermediate from vascular plants. eLife 2020; 9:56664. [PMID: 32840211 PMCID: PMC7447434 DOI: 10.7554/elife.56664] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/22/2020] [Indexed: 11/13/2022] Open
Abstract
Respiration, an essential metabolic process, provides cells with chemical energy. In eukaryotes, respiration occurs via the mitochondrial electron transport chain (mETC) composed of several large membrane-protein complexes. Complex I (CI) is the main entry point for electrons into the mETC. For plants, limited availability of mitochondrial material has curbed detailed biochemical and structural studies of their mETC. Here, we present the cryoEM structure of the known CI assembly intermediate CI* from Vigna radiata at 3.9 Å resolution. CI* contains CI's NADH-binding and CoQ-binding modules, the proximal-pumping module and the plant-specific γ-carbonic-anhydrase domain (γCA). Our structure reveals significant differences in core and accessory subunits of the plant complex compared to yeast, mammals and bacteria, as well as the details of the γCA domain subunit composition and membrane anchoring. The structure sheds light on differences in CI assembly across lineages and suggests potential physiological roles for CI* beyond assembly.
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Affiliation(s)
- Maria Maldonado
- Department of Molecular and Cellular Biology, University of California Davis, Davis, United States
| | - Abhilash Padavannil
- Department of Molecular and Cellular Biology, University of California Davis, Davis, United States
| | - Long Zhou
- Department of Molecular and Cellular Biology, University of California Davis, Davis, United States
| | - Fei Guo
- Department of Molecular and Cellular Biology, University of California Davis, Davis, United States.,BIOEM Facility, University of California Davis, Davis, United States
| | - James A Letts
- Department of Molecular and Cellular Biology, University of California Davis, Davis, United States
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10
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Santos Seica AF, Schimpf J, Friedrich T, Hellwig P. Visualizing the movement of the amphipathic helix in the respiratory complex I using a nitrile infrared probe and SEIRAS. FEBS Lett 2019; 594:491-496. [PMID: 31556114 DOI: 10.1002/1873-3468.13620] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/20/2019] [Accepted: 09/23/2019] [Indexed: 01/22/2023]
Abstract
Conformational movements play an important role in enzyme catalysis. Respiratory complex I, an L-shaped enzyme, connects electron transfer from NADH to ubiquinone in its peripheral arm with proton translocation through its membrane arm by a coupling mechanism still under debate. The amphipathic helix across the membrane arm represents a unique structural feature. Here, we demonstrate a new way to study conformational changes by introducing a small and highly flexible nitrile infrared (IR) label to this helix to visualize movement with surface-enhanced IR absorption spectroscopy. We find that labeled residues K551CL and Y590CL move to a more hydrophobic environment upon NADH reduction of the enzyme, likely as a response to the reorganization of the antiporter-like subunits in the membrane arm.
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Affiliation(s)
- Ana Filipa Santos Seica
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, CMC, Université de Strasbourg CNRS, France
| | - Johannes Schimpf
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Germany
| | | | - Petra Hellwig
- Laboratoire de Bioélectrochimie et Spectroscopie, UMR 7140, CMC, Université de Strasbourg CNRS, France.,University of Strasbourg Institute for Advanced Studies (USIAS), France
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11
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Abstract
Hydrogenases are metal-containing biocatalysts that reversibly convert protons and electrons to hydrogen gas. This reaction can contribute in different ways to the generation of the proton motive force (PMF) of a cell. One means of PMF generation involves reduction of protons on the inside of the cytoplasmic membrane, releasing H2 gas, which being without charge is freely diffusible across the cytoplasmic membrane, where it can be re-oxidized to release protons. A second route of PMF generation couples transfer of electrons derived from H2 oxidation to quinone reduction and concomitant proton uptake at the membrane-bound heme cofactor. This redox-loop mechanism, as originally formulated by Mitchell, requires a second, catalytically distinct, enzyme complex to re-oxidize quinol and release the protons outside the cell. A third way of generating PMF is also by electron transfer to quinones but on the outside of the membrane while directly drawing protons through the entire membrane. The cofactor-less membrane subunits involved are proposed to operate by a conformational mechanism (redox-linked proton pump). Finally, PMF can be generated through an electron bifurcation mechanism, whereby an exergonic reaction is tightly coupled with an endergonic reaction. In all cases the protons can be channelled back inside through a F1F0-ATPase to convert the 'energy' stored in the PMF into the universal cellular energy currency, ATP. New and exciting discoveries employing these mechanisms have recently been made on the bioenergetics of hydrogenases, which will be discussed here and placed in the context of their contribution to energy conservation.
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Affiliation(s)
- Constanze Pinske
- Institute of Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle/Saale, Germany
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12
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Ohnishi T, Ohnishi ST, Salerno JC. Five decades of research on mitochondrial NADH-quinone oxidoreductase (complex I). Biol Chem 2018; 399:1249-1264. [DOI: 10.1515/hsz-2018-0164] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 06/16/2018] [Indexed: 02/06/2023]
Abstract
Abstract
NADH-quinone oxidoreductase (complex I) is the largest and most complicated enzyme complex of the mitochondrial respiratory chain. It is the entry site into the respiratory chain for most of the reducing equivalents generated during metabolism, coupling electron transfer from NADH to quinone to proton translocation, which in turn drives ATP synthesis. Dysfunction of complex I is associated with neurodegenerative diseases such as Parkinson’s and Alzheimer’s, and it is proposed to be involved in aging. Complex I has one non-covalently bound FMN, eight to 10 iron-sulfur clusters, and protein-associated quinone molecules as electron transport components. Electron paramagnetic resonance (EPR) has previously been the most informative technique, especially in membrane in situ analysis. The structure of complex 1 has now been resolved from a number of species, but the mechanisms by which electron transfer is coupled to transmembrane proton pumping remains unresolved. Ubiquinone-10, the terminal electron acceptor of complex I, is detectable by EPR in its one electron reduced, semiquinone (SQ) state. In the aerobic steady state of respiration the semi-ubiquinone anion has been observed and studied in detail. Two distinct protein-associated fast and slow relaxing, SQ signals have been resolved which were designated SQNf and SQNs. This review covers a five decade personal journey through the field leading to a focus on the unresolved questions of the role of the SQ radicals and their possible part in proton pumping.
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Affiliation(s)
- Tomoko Ohnishi
- Department of Biochemistry and Biophysics , Perelman School of Medicine at University of Pennsylvania , Philadelphia, PA 19104 , USA
| | | | - John C. Salerno
- Cell and Molecular Biology Department , Kennesaw State University , Kennesaw, GA 30144 , USA
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13
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Yu H, Wu CH, Schut GJ, Haja DK, Zhao G, Peters JW, Adams MWW, Li H. Structure of an Ancient Respiratory System. Cell 2018; 173:1636-1649.e16. [PMID: 29754813 DOI: 10.1016/j.cell.2018.03.071] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 02/19/2018] [Accepted: 03/27/2018] [Indexed: 02/04/2023]
Abstract
Hydrogen gas-evolving membrane-bound hydrogenase (MBH) and quinone-reducing complex I are homologous respiratory complexes with a common ancestor, but a structural basis for their evolutionary relationship is lacking. Here, we report the cryo-EM structure of a 14-subunit MBH from the hyperthermophile Pyrococcus furiosus. MBH contains a membrane-anchored hydrogenase module that is highly similar structurally to the quinone-binding Q-module of complex I while its membrane-embedded ion-translocation module can be divided into a H+- and a Na+-translocating unit. The H+-translocating unit is rotated 180° in-membrane with respect to its counterpart in complex I, leading to distinctive architectures for the two respiratory systems despite their largely conserved proton-pumping mechanisms. The Na+-translocating unit, absent in complex I, resembles that found in the Mrp H+/Na+ antiporter and enables hydrogen gas evolution by MBH to establish a Na+ gradient for ATP synthesis near 100°C. MBH also provides insights into Mrp structure and evolution of MBH-based respiratory enzymes.
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Affiliation(s)
- Hongjun Yu
- Cryo-EM Structural Biology Laboratory, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Chang-Hao Wu
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Dominik K Haja
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Gongpu Zhao
- David Van Andel Advanced Cryo-Electron Microsocpy Suite, Van Andel Research Institute, Grand Rapids, MI, USA
| | - John W Peters
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99163, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.
| | - Huilin Li
- Cryo-EM Structural Biology Laboratory, Van Andel Research Institute, Grand Rapids, MI 49503, USA.
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14
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Identification and characterization two isoforms of NADH:ubiquinone oxidoreductase from the hyperthermophilic eubacterium Aquifex aeolicus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:366-373. [DOI: 10.1016/j.bbabio.2018.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 02/18/2018] [Accepted: 02/24/2018] [Indexed: 12/20/2022]
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15
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Lamb AM, Gan HM, Greening C, Joseph L, Lee Y, Morán‐Ordóñez A, Sunnucks P, Pavlova A. Climate‐driven mitochondrial selection: A test in Australian songbirds. Mol Ecol 2018; 27:898-918. [DOI: 10.1111/mec.14488] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 11/29/2017] [Accepted: 12/08/2017] [Indexed: 12/22/2022]
Affiliation(s)
- Annika Mae Lamb
- School of Biological Sciences Monash University Melbourne Vic. Australia
| | - Han Ming Gan
- School of Science Monash University Malaysia Bandar Sunway Selangor Malaysia
- Centre for Integrative Ecology School of Life and Environmental Sciences Deakin University Waurn Ponds Vic. Australia
| | - Chris Greening
- School of Biological Sciences Monash University Melbourne Vic. Australia
| | - Leo Joseph
- Australian National Wildlife Collection CSIRO National Research Collections Canberra ACT Australia
| | - Yin Peng Lee
- School of Science Monash University Malaysia Bandar Sunway Selangor Malaysia
| | - Alejandra Morán‐Ordóñez
- InForest Joint Research Unit (CTFC‐CREAF) Forest Science Centre of Catalonia Solsona Catalonia Spain
| | - Paul Sunnucks
- School of Biological Sciences Monash University Melbourne Vic. Australia
| | - Alexandra Pavlova
- School of Biological Sciences Monash University Melbourne Vic. Australia
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16
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Strand DD, Fisher N, Kramer DM. The higher plant plastid NAD(P)H dehydrogenase-like complex (NDH) is a high efficiency proton pump that increases ATP production by cyclic electron flow. J Biol Chem 2017; 292:11850-11860. [PMID: 28559282 DOI: 10.1074/jbc.m116.770792] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 05/26/2017] [Indexed: 12/31/2022] Open
Abstract
Cyclic electron flow around photosystem I (CEF) is critical for balancing the photosynthetic energy budget of the chloroplast by generating ATP without net production of NADPH. We demonstrate that the chloroplast NADPH dehydrogenase complex, a homolog to respiratory Complex I, pumps approximately two protons from the chloroplast stroma to the lumen per electron transferred from ferredoxin to plastoquinone, effectively increasing the efficiency of ATP production via CEF by 2-fold compared with CEF pathways involving non-proton-pumping plastoquinone reductases. By virtue of this proton-pumping stoichiometry, we hypothesize that NADPH dehydrogenase not only efficiently contributes to ATP production but operates near thermodynamic reversibility, with potentially important consequences for remediating mismatches in the thylakoid energy budget.
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Affiliation(s)
- Deserah D Strand
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823
| | - Nicholas Fisher
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823
| | - David M Kramer
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48823; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48823.
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17
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Dörner K, Vranas M, Schimpf J, Straub IR, Hoeser J, Friedrich T. Significance of [2Fe-2S] Cluster N1a for Electron Transfer and Assembly of Escherichia coli Respiratory Complex I. Biochemistry 2017; 56:2770-2778. [DOI: 10.1021/acs.biochem.6b01058] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Katerina Dörner
- Institut
für Biochemie, Albert-Ludwigs-Universität, Albertstraße 21, 79104 Freiburg, Germany
| | - Marta Vranas
- Spemann
Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University, Freiburg, Germany
| | - Johannes Schimpf
- Institut
für Biochemie, Albert-Ludwigs-Universität, Albertstraße 21, 79104 Freiburg, Germany
| | - Isabella R. Straub
- Institut
für Biochemie, Albert-Ludwigs-Universität, Albertstraße 21, 79104 Freiburg, Germany
| | - Jo Hoeser
- Institut
für Biochemie, Albert-Ludwigs-Universität, Albertstraße 21, 79104 Freiburg, Germany
| | - Thorsten Friedrich
- Spemann
Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-University, Freiburg, Germany
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18
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Tursun A, Zhu S, Vik SB. Probing the proton channels in subunit N of Complex I from Escherichia coli through intra-subunit cross-linking. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1840-1848. [PMID: 27632419 DOI: 10.1016/j.bbabio.2016.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 08/19/2016] [Accepted: 09/09/2016] [Indexed: 10/21/2022]
Abstract
Respiratory Complex I appears to have 4 sites for proton translocation, which are coupled to the oxidation of NADH and reduction of coenzyme Q. The proton pathways are thought to be made of offset half-channels that connect to the membrane surfaces, and are connected by a horizontal path through the center of the membrane. In this study of the enzyme from Escherichia coli, subunit N, containing one of the sites, was targeted. Pairs of cysteine residues were introduced into neighboring α-helices along the proposed proton pathways. In an effort to constrain conformational changes that might occur during proton translocation, we attempted to form disulfide bonds or methanethiosulfonate bridges between two engineered cysteine residues. Cysteine modification was inferred by the inability of PEG-maleimide to shift the electrophoretic mobility of subunit N, which will occur upon reaction with free sulfhydryl groups. After the cross-linking treatment, NADH oxidase and NADH-driven proton translocation were measured. Ten different pairs of cysteine residues showed evidence of cross-linking. The most significant loss of enzyme activity was seen for residues near the essential Lys 395. This residue is positioned between the proposed proton half-channel to the periplasm and the horizontal connection through subunit N, and is also near the essential Glu 144 of subunit M. The results suggest important conformational changes in this region for the delivery of protons to the periplasm, or for coupling the actions of subunit N to subunit M.
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Affiliation(s)
- Ablat Tursun
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Shaotong Zhu
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA
| | - Steven B Vik
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275-0376, USA.
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19
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Zhu S, Canales A, Bedair M, Vik SB. Loss of Complex I activity in the Escherichia coli enzyme results from truncating the C-terminus of subunit K, but not from cross-linking it to subunits N or L. J Bioenerg Biomembr 2016; 48:325-33. [PMID: 26931547 DOI: 10.1007/s10863-016-9655-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 02/25/2016] [Indexed: 12/16/2022]
Abstract
Complex I is a multi-subunit enzyme of the respiratory chain with seven core subunits in its membrane arm (A, H, J, K, L, M, and N). In the enzyme from Escherichia coli the C-terminal ten amino acids of subunit K lie along the lateral helix of subunit L, and contribute to a junction of subunits K, L and N on the cytoplasmic surface. Using double cysteine mutagenesis, the cross-linking of subunit K (R99C) to either subunit L (K581C) or subunit N (T292C) was attempted. A partial yield of cross-linked product had no effect on the activity of the enzyme, or on proton translocation, suggesting that the C-terminus of subunit K has no dynamic role in function. To further elucidate the role of subunit K genetic deletions were constructed at the C-terminus. Upon the serial deletion of the last 4 residues of the C-terminus of subunit K, various results were obtained. Deletion of one amino acid had little effect on the activity of Complex I, but deletions of 2 or more amino acids led to total loss of enzyme activity and diminished levels of subunits L, M, and N in preparations of membrane vesicles. Together these results suggest that while the C-terminus of subunit K has no dynamic role in energy transduction by Complex I, it is vital for the correct assembly of the enzyme.
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Affiliation(s)
- Shaotong Zhu
- Department of Biological Sciences, Southern Methodist University, Dallas, TX, 75275-0376, USA.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Alejandra Canales
- Department of Biological Sciences, Southern Methodist University, Dallas, TX, 75275-0376, USA.,Department of Biochemistry, University of Wisconsin, Madison, WI, 53706, USA
| | - Mai Bedair
- Department of Biological Sciences, Southern Methodist University, Dallas, TX, 75275-0376, USA.,University of Texas Southwestern Medical School, Dallas, TX, 75390, USA
| | - Steven B Vik
- Department of Biological Sciences, Southern Methodist University, Dallas, TX, 75275-0376, USA.
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20
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Castro PJ, Silva AF, Marreiros BC, Batista AP, Pereira MM. Respiratory complex I: A dual relation with H(+) and Na(+)? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:928-37. [PMID: 26711319 DOI: 10.1016/j.bbabio.2015.12.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/10/2015] [Accepted: 12/17/2015] [Indexed: 10/22/2022]
Abstract
Respiratory complex I couples NADH:quinone oxidoreduction to ion translocation across the membrane, contributing to the buildup of the transmembrane difference of electrochemical potential. H(+) is well recognized to be the coupling ion of this system but some studies suggested that this role could be also performed by Na(+). We have previously observed NADH-driven Na(+) transport opposite to H(+) translocation by menaquinone-reducing complexes I, which indicated a Na(+)/H(+) antiporter activity in these systems. Such activity was also observed for the ubiquinone-reducing mitochondrial complex I in its deactive form. The relation of Na(+) with complex I may not be surprising since the enzyme has three subunits structurally homologous to bona fide Na(+)/H(+) antiporters and translocation of H(+) and Na(+) ions has been described for members of most types of ion pumps and transporters. Moreover, no clearly distinguishable motifs for the binding of H(+) or Na(+) have been recognized yet. We noticed that in menaquinone-reducing complexes I, less energy is available for ion translocation, compared to ubiquinone-reducing complexes I. Therefore, we hypothesized that menaquinone-reducing complexes I perform Na(+)/H(+) antiporter activity in order to achieve the stoichiometry of 4H(+)/2e(-). In agreement, the organisms that use ubiquinone, a high potential quinone, would have kept such Na(+)/H(+) antiporter activity, only operative under determined conditions. This would imply a physiological role(s) of complex I besides a simple "coupling" of a redox reaction and ion transport, which could account for the sophistication of this enzyme. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.
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Affiliation(s)
- Paulo J Castro
- Instituto de Tecnologia Química e Biológica, António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal
| | - Andreia F Silva
- Instituto de Tecnologia Química e Biológica, António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal
| | - Bruno C Marreiros
- Instituto de Tecnologia Química e Biológica, António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal
| | - Ana P Batista
- Instituto de Tecnologia Química e Biológica, António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica, António Xavier, Universidade Nova de Lisboa, Av. da Republica EAN, 2780-157 Oeiras, Portugal.
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21
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Steimle S, Schnick C, Burger EM, Nuber F, Krämer D, Dawitz H, Brander S, Matlosz B, Schäfer J, Maurer K, Glessner U, Friedrich T. Cysteine scanning reveals minor local rearrangements of the horizontal helix of respiratory complex I. Mol Microbiol 2015; 98:151-61. [PMID: 26115017 DOI: 10.1111/mmi.13112] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/25/2015] [Indexed: 12/22/2022]
Abstract
The NADH:ubiquinone oxidoreductase, respiratory complex I, couples electron transfer from NADH to ubiquinone with the translocation of protons across the membrane. The complex consists of a peripheral arm catalyzing the redox reaction and a membrane arm catalyzing proton translocation. The membrane arm is almost completely aligned by a 110 Å unique horizontal helix that is discussed to transmit conformational changes induced by the redox reaction in a piston-like movement to the membrane arm driving proton translocation. Here, we analyzed such a proposed movement by cysteine-scanning of the helix of the Escherichia coli complex I. The accessibility of engineered cysteine residues and the flexibility of individual positions were determined by labeling the preparations with a fluorescent marker and a spin-probe, respectively, in the oxidized and reduced states. The differences in fluorescence labeling and the rotational flexibility of the spin probe between both redox states indicate only slight conformational changes at distinct positions of the helix but not a large movement.
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Affiliation(s)
- Stefan Steimle
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Christian Schnick
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Eva-Maria Burger
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Franziska Nuber
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Dorothée Krämer
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Hannah Dawitz
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Sofia Brander
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Bartlomiej Matlosz
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Jacob Schäfer
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Katharina Maurer
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Udo Glessner
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
| | - Thorsten Friedrich
- Institut für Biochemie, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104, Freiburg i. Br., Germany
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22
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Zhu S, Vik SB. Constraining the Lateral Helix of Respiratory Complex I by Cross-linking Does Not Impair Enzyme Activity or Proton Translocation. J Biol Chem 2015; 290:20761-20773. [PMID: 26134569 DOI: 10.1074/jbc.m115.660381] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Indexed: 12/19/2022] Open
Abstract
Complex I (NADH:ubiquinone oxidoreductase) is a multisubunit, membrane-bound enzyme of the respiratory chain. The energy from NADH oxidation in the peripheral region of the enzyme is used to drive proton translocation across the membrane. One of the integral membrane subunits, nuoL in Escherichia coli, has an unusual lateral helix of ∼75 residues that lies parallel to the membrane surface and has been proposed to play a mechanical role as a piston during proton translocation (Efremov, R. G., Baradaran, R., and Sazanov, L. A. (2010) Nature 465, 441-445). To test this hypothesis we have introduced 11 pairs of cysteine residues into Complex I; in each pair one is in the lateral helix, and the other is in a nearby region of subunit N, M, or L. The double mutants were treated with Cu(2+) ions or with bi-functional methanethiosulfonate reagents to catalyze cross-link formation in membrane vesicles. The yields of cross-linked products were typically 50-90%, as judged by immunoblotting, but in no case did the activity of Complex I decrease by >10-20%, as indicated by deamino-NADH oxidase activity or rates of proton translocation. In contrast, several pairs of cysteine residues introduced at other interfaces of N:M and M:L subunits led to significant loss of activity, in particular, in the region of residue Glu-144 of subunit M. The results do not support the hypothesis that the lateral helix of subunit L functions like a piston, but rather, they suggest that conformational changes might be transmitted more directly through the functional residues of the proton translocation apparatus.
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Affiliation(s)
- Shaotong Zhu
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275-0376
| | - Steven B Vik
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275-0376.
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23
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Wikström M, Sharma V, Kaila VRI, Hosler JP, Hummer G. New Perspectives on Proton Pumping in Cellular Respiration. Chem Rev 2015; 115:2196-221. [DOI: 10.1021/cr500448t] [Citation(s) in RCA: 183] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mårten Wikström
- Institute
of Biotechnology, University of Helsinki, Biocenter 3 (Viikinkaari 1), PB
65, Helsinki 00014, Finland
| | - Vivek Sharma
- Department
of Physics, Tampere University of Technology, Korkeakoulunkatu 3, Tampere 33720, Finland
| | - Ville R. I. Kaila
- Department
Chemie, Technische Universität München, Lichtenbergstraße 4, D-85748 Garching, Germany
| | - Jonathan P. Hosler
- Department
of Biochemistry, University of Mississippi Medical Center, Jackson, Mississippi 39216, United States
| | - Gerhard Hummer
- Department
of Theoretical Biophysics, Max Planck Institute of Biophysics, Max-von-Laue-Straße
3, 60438 Frankfurt
am Main, Germany
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24
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de Vries S, Dörner K, Strampraad MJF, Friedrich T. Die Elektronentunnelraten im Atmungskettenkomplex I sind auf eine effiziente Energiewandlung abgestimmt. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201410967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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25
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de Vries S, Dörner K, Strampraad MJF, Friedrich T. Electron tunneling rates in respiratory complex I are tuned for efficient energy conversion. Angew Chem Int Ed Engl 2015; 54:2844-8. [PMID: 25600069 PMCID: PMC4506566 DOI: 10.1002/anie.201410967] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Indexed: 12/13/2022]
Abstract
Respiratory complex I converts the free energy of ubiquinone reduction by NADH into a proton motive force, a redox reaction catalyzed by flavin mononucleotide(FMN) and a chain of seven iron–sulfur centers. Electron transfer rates between the centers were determined by ultrafast freeze-quenching and analysis by EPR and UV/Vis spectroscopy. The complex rapidly oxidizes three NADH molecules. The electron-tunneling rate between the most distant centers in the middle of the chain depends on the redox state of center N2 at the end of the chain, and is sixfold slower when N2 is reduced. The conformational changes that accompany reduction of N2 decrease the electronic coupling of the longest electron-tunneling step. The chain of iron–sulfur centers is not just a simple electron-conducting wire; it regulates the electron-tunneling rate synchronizing it with conformation-mediated proton pumping, enabling efficient energy conversion. Synchronization of rates is a principle means of enhancing the specificity of enzymatic reactions.
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Affiliation(s)
- Simon de Vries
- Department of Biotechnology, Institution Delft University of Technology, Julianalaan 67, 2628 BC, Delft (The Netherlands).
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26
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Respiratory complex I fromEscherichia colidoes not transport Na+in the absence of its NuoL subunit. FEBS Lett 2014; 588:4520-5. [DOI: 10.1016/j.febslet.2014.10.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/24/2014] [Accepted: 10/27/2014] [Indexed: 12/23/2022]
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27
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Garvin MR, Bielawski JP, Sazanov LA, Gharrett AJ. Review and meta-analysis of natural selection in mitochondrial complex I in metazoans. J ZOOL SYST EVOL RES 2014. [DOI: 10.1111/jzs.12079] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Michael R. Garvin
- Fisheries Division; School of Fisheries and Ocean Sciences; University of Alaska Fairbanks; Juneau AK USA
| | - Joseph P. Bielawski
- Department of Biology; Dalhousie University; Halifax NS Canada
- Department of Mathematics & Statistics; Dalhousie University; Halifax NS Canada
| | | | - Anthony J. Gharrett
- Fisheries Division; School of Fisheries and Ocean Sciences; University of Alaska Fairbanks; Juneau AK USA
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28
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Tan P, Feng Z, Zhang L, Hou T, Li Y. The mechanism of proton translocation in respiratory complex I from molecular dynamics. J Recept Signal Transduct Res 2014; 35:170-9. [PMID: 25055024 DOI: 10.3109/10799893.2014.942464] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Respiratory complex I, the biggest enzyme of respiratory chain, plays a key role in energy production by the mitochondrial respiratory chain and has been implicated in many human neurodegenerative diseases. Recently, the crystal structure of respiratory complex I is reported. We perform 50 ns molecular dynamics simulations on the membrane domain of respiratory complex I under two hypothetical states (oxidized state and reduced state). We find that the density of water molecules in the trans-membrane domain under reduced state is bigger than that under oxidized state. The connecting elements (helix HL and β-hairpins-helix element) fluctuate stronger under reduced state than that under oxidized state, causing more internal water molecules and facilitating the proton conduction. The conformational changes of helix HL and the crucial charged residue Glu in TM5 play key roles in the mechanism of proton translocation. Our results illustrate the dynamic behavior and the potential mechanism of respiratory complex I, which provides the structural basis for drug design of respiratory complex I.
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Affiliation(s)
- Pengli Tan
- Institute of Functional Nano & Soft Materials (FUNSOM) and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou , China and
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29
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Friedrich T. On the mechanism of respiratory complex I. J Bioenerg Biomembr 2014; 46:255-68. [PMID: 25022766 DOI: 10.1007/s10863-014-9566-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 07/03/2014] [Indexed: 02/08/2023]
Abstract
The energy-converting NADH:ubiquinone oxidoreductase, respiratory complex I, couples the transfer of electrons from NADH to ubiquinone with the translocation of protons across the membrane. Electron microscopy and X-ray crystallography revealed the two-part structure of the enzyme complex. A peripheral arm extending into the aqueous phase catalyzes the electron transfer reaction. Accordingly, this arm contains the redox-active cofactors, namely one flavin mononucleotide (FMN) and up to ten iron-sulfur (Fe/S) clusters. A membrane arm embedded in the lipid bilayer catalyzes proton translocation by a yet unknown mechanism. The binding site of the substrate (ubi) quinone is located at the interface of the two arms. The oxidation of one NADH is coupled with the translocation of four protons across the membrane. In this review, the binding of the substrates, the intramolecular electron transfer, the role of individual Fe/S clusters and the mechanism of proton translocation are discussed in the light of recent data obtained from our laboratory.
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Affiliation(s)
- Thorsten Friedrich
- Institut für Biochemie, Albert-Ludwigs-Universität, Albertstr. 21, 79104, Freiburg, Germany,
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30
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Sato M, Torres-Bacete J, Sinha PK, Matsuno-Yagi A, Yagi T. Essential regions in the membrane domain of bacterial complex I (NDH-1): the machinery for proton translocation. J Bioenerg Biomembr 2014; 46:279-87. [PMID: 24973951 DOI: 10.1007/s10863-014-9558-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Accepted: 06/18/2014] [Indexed: 01/09/2023]
Abstract
The proton-translocating NADH-quinone oxidoreductase (complex I/NDH-1) is the first and largest enzyme of the respiratory chain which has a central role in cellular energy production and is implicated in many human neurodegenerative diseases and aging. It is believed that the peripheral domain of complex I/NDH-1 transfers the electron from NADH to Quinone (Q) and the redox energy couples the proton translocation in the membrane domain. To investigate the mechanism of the proton translocation, in a series of works we have systematically studied all membrane subunits in the Escherichia coli NDH-1 by site-directed mutagenesis. In this mini-review, we have summarized our strategy and results of the mutagenesis by depicting residues essential for proton translocation, along with those for subunit connection. It is suggested that clues to understanding the driving forces of proton translocation lie in the similarities and differences of the membrane subunits, highlighting the communication of essential charged residues among the subunits. A possible proton translocation mechanism with all membrane subunits operating in unison is described.
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Affiliation(s)
- Motoaki Sato
- Department of Molecular and Experimental Medicine, MEM-256, The Scripps Research Institute, La Jolla, CA, 92037, USA,
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31
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Virzintiene E, Moparthi VK, Al-Eryani Y, Shumbe L, Górecki K, Hägerhäll C. Structure and function of the C-terminal domain of MrpA in theBacillus subtilisMrp-antiporter complex - The evolutionary progenitor of the long horizontal helix in complex I. FEBS Lett 2013; 587:3341-7. [DOI: 10.1016/j.febslet.2013.08.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 08/22/2013] [Accepted: 08/23/2013] [Indexed: 01/15/2023]
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32
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Sato M, Sinha PK, Torres-Bacete J, Matsuno-Yagi A, Yagi T. Energy transducing roles of antiporter-like subunits in Escherichia coli NDH-1 with main focus on subunit NuoN (ND2). J Biol Chem 2013; 288:24705-16. [PMID: 23864658 DOI: 10.1074/jbc.m113.482968] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proton-translocating NADH-quinone oxidoreductase (complex I/NDH-1) contains a peripheral and a membrane domain. Three antiporter-like subunits in the membrane domain, NuoL, NuoM, and NuoN (ND5, ND4 and ND2, respectively), are structurally similar. We analyzed the role of NuoN in Escherichia coli NDH-1. The lysine residue at position 395 in NuoN (NLys(395)) is conserved in NuoL (LLys(399)) but is replaced by glutamic acid (MGlu(407)) in NuoM. Our mutation study on NLys(395) suggests that this residue participates in the proton translocation. Furthermore, we found that MGlu(407) is also essential and most likely interacts with conserved LArg(175). Glutamic acids, NGlu(133), MGlu(144), and LGlu(144), are corresponding residues. Unlike mutants of MGlu(144) and LGlu(144), mutation of NGlu(133) scarcely affected the energy-transducing activities. However, a double mutant of NGlu(133) and nearby KGlu(72) showed significant inhibition of these activities. This suggests that NGlu(133) bears a functional role similar to LGlu(144) and MGlu(144) but its mutation can be partially compensated by the nearby carboxyl residue. Conserved prolines located at loops of discontinuous transmembrane helices of NuoL, NuoM, and NuoN were shown to play a similar role in the energy-transducing activity. It seems likely that NuoL, NuoM, and NuoN pump protons by a similar mechanism. Our data also revealed that NLys(158) is one of the key interaction points with helix HL in NuoL. A truncation study indicated that the C-terminal amphipathic segments of NTM14 interacts with the Mβ sheet located on the opposite side of helix HL. Taken together, the mechanism of H(+) translocation in NDH-1 is discussed.
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Affiliation(s)
- Motoaki Sato
- Department of Molecular and Experimental Medicine, MEM-256, The Scripps Research Institute, La Jolla, California 92037, USA
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33
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Abstract
Complex I (NADH:ubiquinone oxidoreductase) is crucial for respiration in many aerobic organisms. In mitochondria, it oxidizes NADH from the tricarboxylic acid cycle and β-oxidation, reduces ubiquinone, and transports protons across the inner membrane, contributing to the proton-motive force. It is also a major contributor to cellular production of reactive oxygen species. The redox reaction of complex I is catalyzed in the hydrophilic domain; it comprises NADH oxidation by a flavin mononucleotide, intramolecular electron transfer along a chain of iron-sulfur clusters, and ubiquinone reduction. Redox-coupled proton translocation in the membrane domain requires long-range energy transfer through the protein complex, and the molecular mechanisms that couple the redox and proton-transfer half-reactions are currently unknown. This review evaluates extant data on the mechanisms of energy transduction and superoxide production by complex I, discusses contemporary mechanistic models, and explores how mechanistic studies may contribute to understanding the roles of complex I dysfunctions in human diseases.
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Affiliation(s)
- Judy Hirst
- Medical Research Council Mitochondrial Biology Unit, Cambridge, CB2 0XY, United Kingdom.
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34
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Torres-Bacete J, Sinha PK, Sato M, Patki G, Kao MC, Matsuno-Yagi A, Yagi T. Roles of subunit NuoK (ND4L) in the energy-transducing mechanism of Escherichia coli NDH-1 (NADH:quinone oxidoreductase). J Biol Chem 2012; 287:42763-72. [PMID: 23105119 DOI: 10.1074/jbc.m112.422824] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The bacterial H(+)-translocating NADH:quinone oxidoreductase (NDH-1) catalyzes electron transfer from NADH to quinone coupled with proton pumping across the cytoplasmic membrane. The NuoK subunit (counterpart of the mitochondrial ND4L subunit) is one of the seven hydrophobic subunits in the membrane domain and bears three transmembrane segments (TM1-3). Two glutamic residues located in the adjacent transmembrane helices of NuoK are important for the energy coupled activity of NDH-1. In particular, mutation of the highly conserved carboxyl residue ((K)Glu-36 in TM2) to Ala led to a complete loss of the NDH-1 activities. Mutation of the second conserved carboxyl residue ((K)Glu-72 in TM3) moderately reduced the activities. To clarify the contribution of NuoK to the mechanism of proton translocation, we relocated these two conserved residues. When we shifted (K)Glu-36 along TM2 to positions 32, 38, 39, and 40, the mutants largely retained energy transducing NDH-1 activities. According to the recent structural information, these positions are located in the vicinity of (K)Glu-36, present in the same helix phase, in an immediately before and after helix turn. In an earlier study, a double mutation of two arginine residues located in a short cytoplasmic loop between TM1 and TM2 (loop-1) showed a drastic effect on energy transducing activities. Therefore, the importance of this cytosolic loop of NuoK ((K)Arg-25, (K)Arg-26, and (K)Asn-27) for the energy transducing activities was extensively studied. The probable roles of subunit NuoK in the energy transducing mechanism of NDH-1 are discussed.
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Affiliation(s)
- Jesus Torres-Bacete
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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35
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Verkhovskaya M, Bloch DA. Energy-converting respiratory Complex I: on the way to the molecular mechanism of the proton pump. Int J Biochem Cell Biol 2012; 45:491-511. [PMID: 22982742 DOI: 10.1016/j.biocel.2012.08.024] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 08/27/2012] [Accepted: 08/28/2012] [Indexed: 12/16/2022]
Abstract
In respiring organisms the major energy transduction flux employs the transmembrane electrochemical proton gradient as a physical link between exergonic redox reactions and endergonic ADP phosphorylation. Establishing the gradient involves electrogenic, transmembrane H(+) translocation by the membrane-embedded respiratory complexes. Among others, Complex I (NADH:ubiquinone oxidoreductase) is the most structurally complex and functionally enigmatic respiratory enzyme; its molecular mechanism is as yet unknown. Here we highlight recent progress and discuss the catalytic events during Complex I turnover in relation to their role in energy conversion and to the enzyme structure.
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Affiliation(s)
- Marina Verkhovskaya
- Helsinki Bioenergetics Group, Institute of Biotechnology, PO Box 65 (Viikinkaari 1) FIN-00014 University of Helsinki, Finland.
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36
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EPR detection of two protein-associated ubiquinone components (SQ(Nf) and SQ(Ns)) in the membrane in situ and in proteoliposomes of isolated bovine heart complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1803-9. [PMID: 22503829 DOI: 10.1016/j.bbabio.2012.03.032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 03/26/2012] [Accepted: 03/29/2012] [Indexed: 02/01/2023]
Abstract
The success of Sazanov's group in determining the X-ray structure of the whole bacterial complex I is a great contribution to the progress of complex I research. In this mini-review of 35years' history of my laboratory and collaborators, we characterized the function of protein-associated semiquinone molecules in the proton-pumping mechanism in complex I (NADH-quinone oxidoreductase). We have constructed most of the frame work of our hypothesis, utilizing EPR techniques before the X-ray structures of complex I were reported by Sazanov's and Brandt's groups. One of the semiquinones (SQ(Nf)) is extremely sensitive to a proton motive force imposed on the energy-transducing membrane, while the other (SQ(Ns)) is insensitive. Their sensitivity to rotenone inhibition also differs. These differences were exploited using tightly coupled bovine heart submitochondrial particles with a high respiratory control ratio (>8). We determined the distance between SQ(Nf) and iron-sulfur cluster N2 on the basis of their direct spin-spin interaction. We are extending this line of work using reconstituted bovine heart complex I proteoliposomes which shows a respiratory control ratio >5. Two frontier research groups support our view point based on their mutagenesis studies. High frequency (33.9GHz; Q-band) EPR experiments appear to favor our two-semiquinone model. This article is part of a Special Issue entitled: 17th European Bioenergetics Conference (EBEC 2012).
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Shiraishi Y, Murai M, Sakiyama N, Ifuku K, Miyoshi H. Fenpyroximate Binds to the Interface between PSST and 49 kDa Subunits in Mitochondrial NADH-Ubiquinone Oxidoreductase. Biochemistry 2012; 51:1953-63. [DOI: 10.1021/bi300047h] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yusuke Shiraishi
- Division
of Applied Life Sciences, Graduate School of Agriculture, and ‡Division of
Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502,
Japan
| | - Masatoshi Murai
- Division
of Applied Life Sciences, Graduate School of Agriculture, and ‡Division of
Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502,
Japan
| | - Naoto Sakiyama
- Division
of Applied Life Sciences, Graduate School of Agriculture, and ‡Division of
Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502,
Japan
| | - Kentaro Ifuku
- Division
of Applied Life Sciences, Graduate School of Agriculture, and ‡Division of
Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502,
Japan
| | - Hideto Miyoshi
- Division
of Applied Life Sciences, Graduate School of Agriculture, and ‡Division of
Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502,
Japan
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Steimle S, Willistein M, Hegger P, Janoschke M, Erhardt H, Friedrich T. Asp563 of the horizontal helix of subunit NuoL is involved in proton translocation by the respiratory complex I. FEBS Lett 2012; 586:699-704. [PMID: 22326235 DOI: 10.1016/j.febslet.2012.01.056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Revised: 01/25/2012] [Accepted: 01/26/2012] [Indexed: 11/30/2022]
Abstract
The NADH:ubiquinone oxidoreductase couples the electron transfer from NADH to ubiquinone with the translocation of protons across the membrane. It contains a 110Å long helix running parallel to the membrane part of the complex. Deletion of the helix resulted in a reduced H(+)/e(-) stoichiometry indicating its direct involvement in proton translocation. Here, we show that the mutation of the conserved amino acid D563(L), which is part of the horizontal helix of the Escherichia coli complex I, leads to a reduced H(+)/e(-) stoichiometry. It is discussed that this residue is involved in transferring protons to the membranous proton translocation site.
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Affiliation(s)
- Stefan Steimle
- Albert-Ludwigs-Universität Freiburg, Institut für Organische Chemie und Biochemie, Freiburg i. Br., Germany
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Dröse S, Brandt U. Molecular mechanisms of superoxide production by the mitochondrial respiratory chain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 748:145-69. [PMID: 22729857 DOI: 10.1007/978-1-4614-3573-0_6] [Citation(s) in RCA: 349] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The mitochondrial respiratory chain is a major source of reactive oxygen species (ROS) in eukaryotic cells. Mitochondrial ROS production associated with a dysfunction of respiratory chain complexes has been implicated in a number of degenerative diseases and biological aging. Recent findings suggest that mitochondrial ROS can be integral components of cellular signal transduction as well. Within the respiratory chain, complexes I (NADH:ubiquinone oxidoreductase) and III (ubiquinol:cytochrome c oxidoreductase; cytochrome bc (1) complex) are generally considered as the main producers of superoxide anions that are released into the mitochondrial matrix and the intermembrane space, respectively. The primary function of both respiratory chain complexes is to employ energy supplied by redox reactions to drive the vectorial transfer of protons into the mitochondrial intermembrane space. This process involves a set of distinct electron carriers designed to minimize the unwanted leak of electrons from reduced cofactors onto molecular oxygen and hence ROS generation under normal circumstances. Nevertheless, it seems plausible that superoxide is derived from intermediates of the normal catalytic cycles of complexes I and III. Therefore, a detailed understanding of the molecular mechanisms driving these enzymes is required to understand mitochondrial ROS production during oxidative stress and redox signalling. This review summarizes recent findings on the chemistry and control of the reactions within respiratory complexes I and III that result in increased superoxide generation. Regulatory contributions of other components of the respiratory chain, especially complex II (succinate:ubiquinone oxidoreductase) and the redox state of the ubiquinone pool (Q-pool) will be briefly discussed.
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Affiliation(s)
- Stefan Dröse
- Center for Membrane Proteomics, Johann Wolfgang Goethe-Universität, Frankfurt am Main, Germany.
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40
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Belevich G, Knuuti J, Verkhovsky MI, Wikström M, Verkhovskaya M. Probing the mechanistic role of the long α-helix in subunit L of respiratory Complex I from Escherichia coli by site-directed mutagenesis. Mol Microbiol 2011; 82:1086-95. [PMID: 22060017 PMCID: PMC3274701 DOI: 10.1111/j.1365-2958.2011.07883.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The C-terminus of the NuoL subunit of Complex I includes a long amphipathic α-helix positioned parallel to the membrane, which has been considered to function as a piston in the proton pumping machinery. Here, we have introduced three types of mutations into the nuoL gene to test the piston-like function. First, NuoL was truncated at its C- and N-termini, which resulted in low production of a fragile Complex I with negligible activity. Second, we mutated three partially conserved residues of the amphipathic α-helix: Asp and Lys residues and a Pro were substituted for acidic, basic or neutral residues. All these variants exhibited almost a wild-type phenotype. Third, several substitutions and insertions were made to reduce rigidity of the amphipathic α-helix, and/or to change its geometry. Most insertions/substitutions resulted in a normal growth phenotype, albeit often with reduced stability of Complex I. In contrast, insertion of six to seven amino acids at a site of the long α-helix between NuoL and M resulted in substantial loss of proton pumping efficiency. The implications of these results for the proton pumping mechanism of Complex I are discussed.
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Affiliation(s)
- Galina Belevich
- Helsinki Bioenergetics Group, Institute of Biotechnology, FIN-00014, University of Helsinki, Helsinki, Finland
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Erhardt H, Steimle S, Muders V, Pohl T, Walter J, Friedrich T. Disruption of individual nuo-genes leads to the formation of partially assembled NADH:ubiquinone oxidoreductase (complex I) in Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:863-71. [PMID: 22063474 DOI: 10.1016/j.bbabio.2011.10.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 10/14/2011] [Accepted: 10/21/2011] [Indexed: 10/15/2022]
Abstract
The proton-pumping NADH:ubiquinone oxidoreductase, respiratory complex I, couples the electron transfer from NADH to ubiquinone with the translocation of protons across the membrane. In Escherichia coli the complex is made up of 13 different subunits encoded by the so-called nuo-genes. Mutants, in which each of the nuo-genes was individually disrupted by the insertion of a resistance cartridge were unable to assemble a functional complex I. Each disruption resulted in the loss of complex I-mediated activity and the failure to extract a structurally intact complex. Thus, all nuo-genes are required either for the assembly or the stability of a functional E. coli complex I. The three subunits comprising the soluble NADH dehydrogenase fragment of the complex were detected in the cytoplasm of several nuo-mutants as one distinct band after BN-PAGE. It is discussed that the fully assembled NADH dehydrogenase fragment represents an assembly intermediate of the E. coli complex I. A partially assembled complex I bound to the membrane was detected in the nuoK and nuoL mutants, respectively. Overproduction of the ΔNuoL variant resulted in the accumulation of two populations of a partially assembled complex in the cytoplasmic membranes. Both populations are devoid of NuoL. One population is enzymatically active, while the other is not. The inactive population is missing cluster N2 and is tightly associated with the inducible lysine decarboxylase. This article is part of a Special Issue entitled: Biogenesis/Assembly of Respiratory Enzyme Complexes.
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Affiliation(s)
- Heiko Erhardt
- Albert-Ludwigs-Universität, Freiburg, Institut für Organische Chemie und Biochemie and Spemann Graduate School of Biology and Medicine, Albertstr. 21, 79104 Freiburg i. Br., Germany
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Garvin MR, Bielawski JP, Gharrett AJ. Positive Darwinian selection in the piston that powers proton pumps in complex I of the mitochondria of Pacific salmon. PLoS One 2011; 6:e24127. [PMID: 21969854 PMCID: PMC3182164 DOI: 10.1371/journal.pone.0024127] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 08/04/2011] [Indexed: 11/23/2022] Open
Abstract
The mechanism of oxidative phosphorylation is well understood, but evolution of the proteins involved is not. We combined phylogenetic, genomic, and structural biology analyses to examine the evolution of twelve mitochondrial encoded proteins of closely related, yet phenotypically diverse, Pacific salmon. Two separate analyses identified the same seven positively selected sites in ND5. A strong signal was also detected at three sites of ND2. An energetic coupling analysis revealed several structures in the ND5 protein that may have co-evolved with the selected sites. These data implicate Complex I, specifically the piston arm of ND5 where it connects the proton pumps, as important in the evolution of Pacific salmon. Lastly, the lineage to Chinook experienced rapid evolution at the piston arm.
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Affiliation(s)
- Michael R Garvin
- Fisheries Division, School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, United States of America.
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Abstract
Mitochondria are the structures that produce the bulk part of the cellular energy currency ATP, which drives numerous energy requiring processes in the cell. This process involves a series of large enzyme complexes—the respiratory chain—that couples the transfer of electrons to the creation of a concentration gradient of protons across the inner mitochondrial membrane, which drives ATP synthesis. Complex I (or NADH-quinone oxidoreductase) is the largest and by far the most complicated of the respiratory chain enzyme complexes. The molecular mechanism whereby it couples electron transfer to proton extrusion has remained mysterious until very recently. Low-resolution X-ray structures of complex I have, surprisingly, suggested that electron transfer in the hydrophilic arm, protruding into the mitochondrial matrix, causes movement of a coupling rod that influences three putative proton pumps within the hydrophobic arm embedded in the inner mitochondrial membrane. In this Primer, we will briefly introduce the recent progress made in this area and highlight the road ahead that likely will unravel the detailed molecular mechanisms of complex I function.
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Torres-Bacete J, Sinha PK, Matsuno-Yagi A, Yagi T. Structural contribution of C-terminal segments of NuoL (ND5) and NuoM (ND4) subunits of complex I from Escherichia coli. J Biol Chem 2011; 286:34007-14. [PMID: 21835926 DOI: 10.1074/jbc.m111.260968] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proton-translocating NADH-quinone oxidoreductase (complex I/NDH-1) is a multisubunit enzymatic complex. It has a characteristic L-shaped form with two domains, a hydrophilic peripheral domain and a hydrophobic membrane domain. The membrane domain contains three antiporter-like subunits (NuoL, NuoM, and NuoN, Escherichia coli naming) that are considered to be involved in the proton translocation. Deletion of either NuoL or NuoM resulted in an incomplete assembly of NDH-1 and a total loss of the NADH-quinone oxidoreductase activity. We have truncated the C terminus segments of NuoM and NuoL by introducing STOP codons at different locations using site-directed mutagenesis of chromosomal DNA. Our results suggest an important structural role for the C-terminal segments of both subunits. The data further advocate that the elimination of the last transmembrane helix (TM14) of NuoM and the TM16 (at least C-terminal seven residues) or together with the HL helix and the TM15 of the NuoL subunit lead to reduced stability of the membrane arm and therefore of the whole NDH-1 complex. A region of NuoL critical for stability of NDH-1 architecture has been discussed.
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Affiliation(s)
- Jesus Torres-Bacete
- Department of Molecular and Experimental Medicine, MEM-256, The Scripps Research Institute, La Jolla, California 92037, USA
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45
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Efremov RG, Sazanov LA. Respiratory complex I: 'steam engine' of the cell? Curr Opin Struct Biol 2011; 21:532-40. [PMID: 21831629 DOI: 10.1016/j.sbi.2011.07.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/01/2011] [Accepted: 07/07/2011] [Indexed: 12/19/2022]
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.
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Affiliation(s)
- Rouslan G Efremov
- Medical Research Council Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
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46
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Structure of the membrane domain of respiratory complex I. Nature 2011; 476:414-20. [PMID: 21822288 DOI: 10.1038/nature10330] [Citation(s) in RCA: 306] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 06/24/2011] [Indexed: 01/30/2023]
Abstract
Complex I is the first and largest enzyme of the respiratory chain, coupling electron transfer between NADH and ubiquinone to the translocation of four protons across the membrane. It has a central role in cellular energy production and has been implicated in many human neurodegenerative diseases. The L-shaped enzyme consists of hydrophilic and membrane domains. Previously, we determined the structure of the hydrophilic domain. Here we report the crystal structure of the Esherichia coli complex I membrane domain at 3.0 Å resolution. It includes six subunits, NuoL, NuoM, NuoN, NuoA, NuoJ and NuoK, with 55 transmembrane helices. The fold of the homologous antiporter-like subunits L, M and N is novel, with two inverted structural repeats of five transmembrane helices arranged, unusually, face-to-back. Each repeat includes a discontinuous transmembrane helix and forms half of a channel across the membrane. A network of conserved polar residues connects the two half-channels, completing the proton translocation pathway. Unexpectedly, lysines rather than carboxylate residues act as the main elements of the proton pump in these subunits. The fourth probable proton-translocation channel is at the interface of subunits N, K, J and A. The structure indicates that proton translocation in complex I, uniquely, involves coordinated conformational changes in six symmetrical structural elements.
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