1
|
Laube E, Schiller J, Zickermann V, Vonck J. Using cryo-EM to understand the assembly pathway of respiratory complex I. Acta Crystallogr D Struct Biol 2024; 80:159-173. [PMID: 38372588 PMCID: PMC10910544 DOI: 10.1107/s205979832400086x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/23/2024] [Indexed: 02/20/2024] Open
Abstract
Complex I (proton-pumping NADH:ubiquinone oxidoreductase) is the first component of the mitochondrial respiratory chain. In recent years, high-resolution cryo-EM studies of complex I from various species have greatly enhanced the understanding of the structure and function of this important membrane-protein complex. Less well studied is the structural basis of complex I biogenesis. The assembly of this complex of more than 40 subunits, encoded by nuclear or mitochondrial DNA, is an intricate process that requires at least 20 different assembly factors in humans. These are proteins that are transiently associated with building blocks of the complex and are involved in the assembly process, but are not part of mature complex I. Although the assembly pathways have been studied extensively, there is limited information on the structure and molecular function of the assembly factors. Here, the insights that have been gained into the assembly process using cryo-EM are reviewed.
Collapse
Affiliation(s)
- Eike Laube
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Jonathan Schiller
- Institute of Biochemistry II, University Hospital, Goethe University, 60590 Frankfurt am Main, Germany
- Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, 60438 Frankfurt am Main, Germany
| | - Volker Zickermann
- Institute of Biochemistry II, University Hospital, Goethe University, 60590 Frankfurt am Main, Germany
- Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, 60438 Frankfurt am Main, Germany
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| |
Collapse
|
2
|
Srikant S, Gaudet R, Murray AW. Extending the reach of homology by using successive computational filters to find yeast pheromone genes. Curr Biol 2023; 33:4098-4110.e3. [PMID: 37699395 PMCID: PMC10592104 DOI: 10.1016/j.cub.2023.08.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 07/04/2023] [Accepted: 08/14/2023] [Indexed: 09/14/2023]
Abstract
The mating of fungi depends on pheromones that mediate communication between two mating types. Most species use short peptides as pheromones, which are either unmodified (e.g., α-factor in Saccharomyces cerevisiae) or C-terminally farnesylated (e.g., a-factor in S. cerevisiae). Peptide pheromones have been found by genetics or biochemistry in a small number of fungi, but their short sequences and modest conservation make it impossible to detect homologous sequences in most species. To overcome this problem, we used a four-step computational pipeline to identify candidate a-factor genes in sequenced genomes of the Saccharomycotina, the fungal clade that contains most of the yeasts: we require that candidate genes have a C-terminal prenylation motif, are shorter than 100 amino acids long, and contain a proteolytic-processing motif upstream of the potential mature pheromone sequence and that closely related species contain highly conserved homologs of the potential mature pheromone sequence. Additional manual curation exploits the observation that many species carry more than one a-factor gene, encoding identical or nearly identical pheromones. From 332 Saccharomycotina genomes, we identified strong candidate pheromone genes in 241 genomes, covering 13 clades that are each separated from each other by at least 100 million years, the time required for evolution to remove detectable sequence homology among small pheromone genes. For one small clade, the Yarrowia, we demonstrated that our algorithm found the a-factor genes: deleting all four related genes in the a-mating type of Yarrowia lipolytica prevents mating.
Collapse
Affiliation(s)
- Sriram Srikant
- Department of Molecular and Cellular Biology, Harvard University, Oxford Street, Cambridge, MA 02138, USA
| | - Rachelle Gaudet
- Department of Molecular and Cellular Biology, Harvard University, Oxford Street, Cambridge, MA 02138, USA
| | - Andrew W Murray
- Department of Molecular and Cellular Biology, Harvard University, Oxford Street, Cambridge, MA 02138, USA.
| |
Collapse
|
3
|
Torino S, Dhurandhar M, Stroobants A, Claessens R, Efremov RG. Time-resolved cryo-EM using a combination of droplet microfluidics with on-demand jetting. Nat Methods 2023; 20:1400-1408. [PMID: 37592181 DOI: 10.1038/s41592-023-01967-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 06/27/2023] [Indexed: 08/19/2023]
Abstract
Single-particle cryogenic electron microscopy (cryo-EM) allows reconstruction of high-resolution structures of proteins in different conformations. Protein function often involves transient functional conformations, which can be resolved using time-resolved cryo-EM (trEM). In trEM, reactions are arrested after a defined delay time by rapid vitrification of protein solution on the EM grid. Despite the increasing interest in trEM among the cryo-EM community, making trEM samples with a time resolution below 100 ms remains challenging. Here we report the design and the realization of a time-resolved cryo-plunger that combines a droplet-based microfluidic mixer with a laser-induced generator of microjets that allows rapid reaction initiation and plunge-freezing of cryo-EM grids. Using this approach, a time resolution of 5 ms was achieved and the protein density map was reconstructed to a resolution of 2.1 Å. trEM experiments on GroEL:GroES chaperonin complex resolved the kinetics of the complex formation and visualized putative short-lived conformations of GroEL-ATP complex.
Collapse
Affiliation(s)
- Stefania Torino
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Mugdha Dhurandhar
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Annelore Stroobants
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Raf Claessens
- Research Group Electrochemical and Surface Engineering, Vrije Universiteit Brussel, Brussels, Belgium
| | - Rouslan G Efremov
- Center for Structural Biology, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.
- Structural Biology Brussels, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium.
| |
Collapse
|
4
|
Murari A, Rhooms SK, Vimal D, Hossain KFB, Saini S, Villanueva M, Schlame M, Owusu-Ansah E. Phospholipids can regulate complex I assembly independent of their role in maintaining mitochondrial membrane integrity. Cell Rep 2023; 42:112846. [PMID: 37516961 DOI: 10.1016/j.celrep.2023.112846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 05/22/2023] [Accepted: 07/06/2023] [Indexed: 08/01/2023] Open
Abstract
Several phospholipid (PL) molecules are intertwined with some mitochondrial complex I (CI) subunits in the membrane domain of CI, but their function is unclear. We report that when the Drosophila melanogaster ortholog of the intramitochondrial PL transporter, STARD7, is severely disrupted, assembly of the oxidative phosphorylation (OXPHOS) system is impaired, and the biogenesis of several CI subcomplexes is hampered. However, intriguingly, a restrained knockdown of STARD7 impairs the incorporation of NDUFS5 and NDUFA1 into the proximal part of the CI membrane domain without directly affecting the incorporation of subunits in the distal part of the membrane domain, OXPHOS complexes already assembled, or mitochondrial cristae integrity. Importantly, the restrained knockdown of STARD7 appears to induce a modest amount of cardiolipin remodeling, indicating that there could be some alteration in the composition of the mitochondrial phospholipidome. We conclude that PLs can regulate CI biogenesis independent of their role in maintaining mitochondrial membrane integrity.
Collapse
Affiliation(s)
- Anjaneyulu Murari
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Shauna-Kay Rhooms
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Divya Vimal
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Kaniz Fatima Binte Hossain
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Sanjay Saini
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Maximino Villanueva
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Michael Schlame
- Departments of Anesthesiology and Cell Biology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Edward Owusu-Ansah
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA.
| |
Collapse
|
5
|
Tunnel dynamics of quinone derivatives and its coupling to protein conformational rearrangements in respiratory complex I. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148951. [PMID: 36509126 DOI: 10.1016/j.bbabio.2022.148951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
Respiratory complex I in mitochondria and bacteria catalyzes the transfer of electrons from NADH to quinone (Q). The free energy available from the reaction is used to pump protons and to establish a membrane proton electrochemical gradient, which drives ATP synthesis. Even though several high-resolution structures of complex I have been resolved, how Q reduction is linked with proton pumping, remains unknown. Here, microsecond long molecular dynamics (MD) simulations were performed on Yarrowia lipolytica complex I structures where Q molecules have been resolved in the ~30 Å long Q tunnel. MD simulations of several different redox/protonation states of Q reveal the coupling between the Q dynamics and the restructuring of conserved loops and ion pairs. Oxidized quinone stabilizes towards the N2 FeS cluster, a binding mode not previously described in Yarrowia lipolytica complex I structures. On the other hand, reduced (and protonated) species tend to diffuse towards the Q binding sites closer to the tunnel entrance. Mechanistic and physiological relevance of these results are discussed.
Collapse
|
6
|
Burnap RL. Cyanobacterial Bioenergetics in Relation to Cellular Growth and Productivity. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2023; 183:25-64. [PMID: 36764956 DOI: 10.1007/10_2022_215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Cyanobacteria, the evolutionary originators of oxygenic photosynthesis, have the capability to convert CO2, water, and minerals into biomass using solar energy. This process is driven by intricate bioenergetic mechanisms that consist of interconnected photosynthetic and respiratory electron transport chains coupled. Over the last few decades, advances in physiochemical analysis, molecular genetics, and structural analysis have enabled us to gain a more comprehensive understanding of cyanobacterial bioenergetics. This includes the molecular understanding of the primary energy conversion mechanisms as well as photoprotective and other dissipative mechanisms that prevent photodamage when the rates of photosynthetic output, primarily in the form of ATP and NADPH, exceed the rates that cellular assimilatory processes consume these photosynthetic outputs. Despite this progress, there is still much to learn about the systems integration and the regulatory circuits that control expression levels for optimal cellular abundance and activity of the photosynthetic complexes and the cellular components that convert their products into biomass. With an improved understanding of these regulatory principles and mechanisms, it should be possible to optimally modify cyanobacteria for enhanced biotechnological purposes.
Collapse
Affiliation(s)
- Robert L Burnap
- Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK, USA.
| |
Collapse
|
7
|
Alkhaldi HA, Vik SB. Analysis of compound heterozygous and homozygous mutations found in peripheral subunits of human respiratory Complex I, NDUFS1, NDUFS2, NDUFS8 and NDUFV1, by modeling in the E. coli enzyme. Mitochondrion 2023; 68:87-104. [PMID: 36462614 PMCID: PMC9805526 DOI: 10.1016/j.mito.2022.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 11/14/2022] [Accepted: 11/26/2022] [Indexed: 12/05/2022]
Abstract
Respiratory Complex I (NADH:ubiquinone oxidoreductase) is composed of 45 subunits, seven mitochondrially-encoded and 38 imported. Mutations in the nuclearly-encoded subunits have been regularly discovered in humans in recent years, and many lead to cardiomyopathy, Leigh Syndrome, and early death. From the literature, we have identified mutations at 17 different sites and constructed 31 mutants in a bacterial model system. Many of these mutations, found in NDUFS1, NDUFS2, NDUFS8, and NDUFV1, map to subunit interfaces, and we hypothesized that they would disrupt assembly of Complex I. The mutations were constructed in the homologous E. coli genes, nuoG, nuoCD, nuoI and nuoF, respectively, and expressed from a plasmid containing all Complex I genes. Membrane vesicles were prepared and rates of deamino-NADH oxidase activity measured, which indicated a range of reduced activity. Some mutants were also analyzed using recently developed assays of assembly, time-delayed expression, and co-immunoprecipitation, which showed that assembly was disrupted. With compound heterozygotes, we determined which mutation was more deleterious. Construction of alanine mutations allowed us to distinguish between phenotypes that were caused by loss of the original amino acid or introduction of the mutant residue.
Collapse
Affiliation(s)
- Hind A Alkhaldi
- 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.
| |
Collapse
|
8
|
Wikström M, Djurabekova A, Sharma V. On the role of ubiquinone in the proton translocation mechanism of respiratory complex I. FEBS Lett 2023; 597:224-236. [PMID: 36180980 DOI: 10.1002/1873-3468.14506] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/23/2022] [Accepted: 09/23/2022] [Indexed: 01/26/2023]
Abstract
Complex I converts oxidoreduction energy into a proton electrochemical gradient across the inner mitochondrial or bacterial cell membrane. This gradient is the primary source of energy for aerobic synthesis of ATP. Oxidation of reduced nicotinamide adenine dinucleotide (NADH) by ubiquinone (Q) yields NAD+ and ubiquinol (QH2 ), which is tightly coupled to translocation of four protons from the negatively to the positively charged side of the membrane. Electrons from NADH oxidation reach the iron-sulfur centre N2 positioned near the bottom of a tunnel that extends circa 30 Å from the membrane domain into the hydrophilic domain of the complex. The tunnel is occupied by ubiquinone, which can take a distal position near the N2 centre or proximal positions closer to the membrane. Here, we review important structural, kinetic and thermodynamic properties of ubiquinone that define its role in complex I function. We suggest that this function exceeds that of a mere substrate or electron acceptor and propose that ubiquinone may be the redox element of complex I coupling electron transfer to proton translocation.
Collapse
Affiliation(s)
- Mårten Wikström
- HiLIFE Institute of Biotechnology, University of Helsinki, Finland
| | | | - Vivek Sharma
- HiLIFE Institute of Biotechnology, University of Helsinki, Finland.,Department of Physics, University of Helsinki, Finland
| |
Collapse
|
9
|
Chung I, Grba DN, Wright JJ, Hirst J. Making the leap from structure to mechanism: are the open states of mammalian complex I identified by cryoEM resting states or catalytic intermediates? Curr Opin Struct Biol 2022; 77:102447. [PMID: 36087446 PMCID: PMC7614202 DOI: 10.1016/j.sbi.2022.102447] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/07/2022] [Accepted: 07/26/2022] [Indexed: 12/14/2022]
Abstract
Respiratory complex I (NADH:ubiquinone oxidoreductase) is a multi-subunit, energy-transducing mitochondrial enzyme that is essential for oxidative phosphorylation and regulating NAD+/NADH pools. Despite recent advances in structural knowledge and a long history of biochemical analyses, the mechanism of redox-coupled proton translocation by complex I remains unknown. Due to its ability to separate molecules in a mixed population into distinct classes, single-particle electron cryomicroscopy has enabled identification and characterisation of different complex I conformations. However, deciding on their catalytic and/or regulatory properties to underpin mechanistic hypotheses, especially without detailed biochemical characterisation of the structural samples, has proven challenging. In this review we explore different mechanistic interpretations of the closed and open states identified in cryoEM analyses of mammalian complex I.
Collapse
Affiliation(s)
- Injae Chung
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - Daniel N Grba
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - John J Wright
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK
| | - Judy Hirst
- MRC Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY, UK.
| |
Collapse
|
10
|
Laube E, Meier-Credo J, Langer JD, Kühlbrandt W. Conformational changes in mitochondrial complex I of the thermophilic eukaryote Chaetomium thermophilum. SCIENCE ADVANCES 2022; 8:eadc9952. [PMID: 36427319 PMCID: PMC9699679 DOI: 10.1126/sciadv.adc9952] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/07/2022] [Indexed: 05/23/2023]
Abstract
Mitochondrial complex I is a redox-driven proton pump that generates proton-motive force across the inner mitochondrial membrane, powering oxidative phosphorylation and ATP synthesis in eukaryotes. We report the structure of complex I from the thermophilic fungus Chaetomium thermophilum, determined by cryoEM up to 2.4-Å resolution. We show that the complex undergoes a transition between two conformations, which we refer to as state 1 and state 2. The conformational switch is manifest in a twisting movement of the peripheral arm relative to the membrane arm, but most notably in substantial rearrangements of the Q-binding cavity and the E-channel, resulting in a continuous aqueous passage from the E-channel to subunit ND5 at the far end of the membrane arm. The conformational changes in the complex interior resemble those reported for mammalian complex I, suggesting a highly conserved, universal mechanism of coupling electron transport to proton pumping.
Collapse
Affiliation(s)
- Eike Laube
- Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Jakob Meier-Credo
- Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
- Max-Planck-Institute for Brain Research, Frankfurt 60438, Germany
| | - Julian D. Langer
- Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
- Max-Planck-Institute for Brain Research, Frankfurt 60438, Germany
| | | |
Collapse
|
11
|
Alkhaldi HA, Phan DH, Vik SB. Analysis of Human Clinical Mutations of Mitochondrial ND1 in a Bacterial Model System for Complex I. Life (Basel) 2022; 12:1934. [PMID: 36431069 PMCID: PMC9696053 DOI: 10.3390/life12111934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/13/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
The most common causes of mitochondrial dysfunction and disease include mutations in subunits and assembly factors of Complex I. Numerous mutations in the mitochondrial gene ND1 have been identified in humans. Currently, a bacterial model system provides the only method for rapid construction and analysis of mutations in homologs of human ND1. In this report, we have identified nine mutations in human ND1 that are reported to be pathogenic and are located at subunit interfaces. Our hypothesis was that these mutations would disrupt Complex I assembly. Seventeen mutations were constructed in the homologous nuoH gene in an E. coli model system. In addition to the clinical mutations, alanine substitutions were constructed in order to distinguish between a deleterious effect from the introduction of the mutant residue and the loss of the original residue. The mutations were moved to an expression vector containing all thirteen genes of the E. coli nuo operon coding for Complex I. Membrane vesicles were prepared and rates of deamino-NADH oxidase activity and proton translocation were measured. Samples were also tested for assembly by native gel electrophoresis and for expression of NuoH by immunoblotting. A range of outcomes was observed: Mutations at four of the sites allow normal assembly with moderate activity (50−76% of wild type). Mutations at the other sites disrupt assembly and/or activity, and in some cases the outcomes depend upon the amino acid introduced. In general, the outcomes are consistent with the proposed pathogenicity in humans.
Collapse
Affiliation(s)
| | | | - Steven B. Vik
- Department of Biological Sciences, Southern Methodist University, Dallas, TX 75275, USA
| |
Collapse
|
12
|
Alkhaldi HA, Vik SB. Subunits E-F-G of E. coli Complex I can form an active complex when expressed alone, but in time-delayed assembly co-expression of B-CD-E-F-G is optimal. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148593. [PMID: 35850264 PMCID: PMC9783743 DOI: 10.1016/j.bbabio.2022.148593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/15/2022] [Accepted: 07/11/2022] [Indexed: 12/27/2022]
Abstract
Respiratory Complex I from E. coli is a proto-type of the mitochondrial enzyme, consisting of a 6-subunit peripheral arm (B-CD-E-F-G-I) and a 7-subunit membrane arm. When subunits E-F-G (N-module), were expressed alone they formed an active complex as determined by co-immunoprecipitation and native gel electrophoresis. When co-expressed with subunits B and CD, only a complex of E-F-G was found. When these five subunits were co-expressed with subunit I and two membrane subunits, A and H, a complex of B-CD-E-F-G-I was membrane-bound, constituting the N- and Q-modules. Assembly of Complex I was also followed by splitting the genes between two plasmids, in three different groupings, and expressing them simultaneously, or with time-delay of expression from one plasmid. When the B-CD-E-F-G genes were co-expressed after a time-delay, assembly was over 90 % of that when the whole operon was expressed together. In summary, E-F-G was the only soluble subcomplex detected in these studies, but assembly was not optimal when these subunits were expressed either first or last. Co-expression of subunits B and CD with E-F-G provided a higher level of assembly, indicating that integrated assembly of N- and Q-modules provides a more efficient pathway.
Collapse
Affiliation(s)
- Hind A Alkhaldi
- 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.
| |
Collapse
|
13
|
Steinhilper R, Höff G, Heider J, Murphy BJ. Structure of the membrane-bound formate hydrogenlyase complex from Escherichia coli. Nat Commun 2022; 13:5395. [PMID: 36104349 PMCID: PMC9474812 DOI: 10.1038/s41467-022-32831-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 08/08/2022] [Indexed: 01/30/2023] Open
Abstract
The prototypical hydrogen-producing enzyme, the membrane-bound formate hydrogenlyase (FHL) complex from Escherichia coli, links formate oxidation at a molybdopterin-containing formate dehydrogenase to proton reduction at a [NiFe] hydrogenase. It is of intense interest due to its ability to efficiently produce H2 during fermentation, its reversibility, allowing H2-dependent CO2 reduction, and its evolutionary link to respiratory complex I. FHL has been studied for over a century, but its atomic structure remains unknown. Here we report cryo-EM structures of FHL in its aerobically and anaerobically isolated forms at resolutions reaching 2.6 Å. This includes well-resolved density for conserved loops linking the soluble and membrane arms believed to be essential in coupling enzymatic turnover to ion translocation across the membrane in the complex I superfamily. We evaluate possible structural determinants of the bias toward hydrogen production over its oxidation and describe an unpredicted metal-binding site near the interface of FdhF and HycF subunits that may play a role in redox-dependent regulation of FdhF interaction with the complex. New cryo-EM structures of the formate hydrogenlyase complex from the model bacterium E. coli clarify how electrons and protons move through the complex and are combined to make H2 gas. The complex shows important similarities and differences to related bioenergetic complexes across the tree of life.
Collapse
|
14
|
Binding of Natural Inhibitors to Respiratory Complex I. Pharmaceuticals (Basel) 2022; 15:ph15091088. [PMID: 36145309 PMCID: PMC9503403 DOI: 10.3390/ph15091088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 11/26/2022] Open
Abstract
NADH:ubiquinone oxidoreductase (respiratory complex I) is a redox-driven proton pump with a central role in mitochondrial oxidative phosphorylation. The ubiquinone reduction site of complex I is located in the matrix arm of this large protein complex and connected to the membrane via a tunnel. A variety of chemically diverse compounds are known to inhibit ubiquinone reduction by complex I. Rotenone, piericidin A, and annonaceous acetogenins are representatives of complex I inhibitors from biological sources. The structure of complex I is determined at high resolution, and inhibitor binding sites are described in detail. In this review, we summarize the state of knowledge of how natural inhibitors bind in the Q reduction site and the Q access pathway and how their inhibitory mechanisms compare with that of a synthetic anti-cancer agent.
Collapse
|
15
|
Piper SJ, Johnson RM, Wootten D, Sexton PM. Membranes under the Magnetic Lens: A Dive into the Diverse World of Membrane Protein Structures Using Cryo-EM. Chem Rev 2022; 122:13989-14017. [PMID: 35849490 DOI: 10.1021/acs.chemrev.1c00837] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Membrane proteins are highly diverse in both structure and function and can, therefore, present different challenges for structure determination. They are biologically important for cells and organisms as gatekeepers for information and molecule transfer across membranes, but each class of membrane proteins can present unique obstacles to structure determination. Historically, many membrane protein structures have been investigated using highly engineered constructs or using larger fusion proteins to improve solubility and/or increase particle size. Other strategies included the deconstruction of the full-length protein to target smaller soluble domains. These manipulations were often required for crystal formation to support X-ray crystallography or to circumvent lower resolution due to high noise and dynamic motions of protein subdomains. However, recent revolutions in membrane protein biochemistry and cryo-electron microscopy now provide an opportunity to solve high resolution structures of both large, >1 megadalton (MDa), and small, <100 kDa (kDa), drug targets in near-native conditions, routinely reaching resolutions around or below 3 Å. This review provides insights into how the recent advances in membrane biology and biochemistry, as well as technical advances in cryo-electron microscopy, help us to solve structures of a large variety of membrane protein groups, from small receptors to large transporters and more complex machineries.
Collapse
Affiliation(s)
- Sarah J Piper
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Rachel M Johnson
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Denise Wootten
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| | - Patrick M Sexton
- Drug Discovery Biology theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia.,ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Victoria, Australia
| |
Collapse
|
16
|
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.
Collapse
|
17
|
Jeon TJ, Lee SG, Yoo SH, Kim M, Song D, Ryu J, Park H, Kim DS, Hyun J, Kim HM, Ryu SE. A Dynamic Substrate Pool Revealed by cryo-EM of a Lipid-Preserved Respiratory Supercomplex. Antioxid Redox Signal 2022; 36:1101-1118. [PMID: 34913730 DOI: 10.1089/ars.2021.0114] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Aims: Mitochondrial respiratory supercomplexes mediate redox electron transfer, generating a proton gradient for ATP synthesis. To provide structural information on the function of supercomplexes in physiologically relevant conditions, we conducted cryoelectron microscopy studies with supercomplexes in a lipid-preserving state. Results: Here, we present cryoelectron microscopy structures of bovine respiratory supercomplex I1III2IV1 by using a lipid-preserving sample preparation. The preparation greatly enhances the intercomplex quinone transfer activity. The structures reveal large intercomplex motions that result in different shapes and sizes of the intercomplex space between complexes I and III, forming a dynamic substrate pool. Biochemical and structural analyses indicated that intercomplex phospholipids mediate the intercomplex motions. An analysis of the different classes of focus-refined complex I showed that structural switches due to quinone reduction led to the formation of a novel channel that could transfer reduced quinones to the intercomplex substrate pool. Innovation and Conclusion: Our results indicate potential mechanism for the facilitated electron transfer involving a dynamic substrate pool and intercomplex movement by which supercomplexes play an active role in the regulation of metabolic flux and reactive oxygen species.
Collapse
Affiliation(s)
- Tae Jin Jeon
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Korea
- National Instrumentation Center for Environmental Management (NICEM), Seoul National University, Seoul, Korea
| | - Seong-Gyu Lee
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
- Center for Biomolecular and Cellular Structure, Institute for Basic Science (IBS), Daejeon, Korea
| | - Suk Hyun Yoo
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Korea
| | - Myeongbin Kim
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Korea
| | - Dabin Song
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Korea
| | - Joonghyun Ryu
- Voronoi Diagram Research Center, Hanyang University, Seoul, Korea
| | - Hwangseo Park
- Department of Bioscience and Biotechnology, Sejong University, Seoul, Korea
| | - Deok-Soo Kim
- Voronoi Diagram Research Center, Hanyang University, Seoul, Korea
- School of Mechanical Engineering, College of Engineering, Hanyang University, Seoul, Korea
| | - Jaekyung Hyun
- Department of Convergence Medicine, Pusan National University Medical School, Gyeongsangnamdo, Korea
- Electron Microscopy Research Center, Korea Basic Science Institute (KBSI), Chungcheongbukdo, Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea
- Center for Biomolecular and Cellular Structure, Institute for Basic Science (IBS), Daejeon, Korea
| | - Seong Eon Ryu
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Korea
| |
Collapse
|
18
|
Djurabekova A, Galemou Yoga E, Nyman A, Pirttikoski A, Zickermann V, Haapanen O, Sharma V. Docking and molecular simulations reveal a quinone binding site on the surface of respiratory complex I. FEBS Lett 2022; 596:1133-1146. [PMID: 35363885 DOI: 10.1002/1873-3468.14346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 03/11/2022] [Accepted: 03/24/2022] [Indexed: 11/07/2022]
Abstract
The first component of the mitochondrial electron transport chain is respiratory complex I. Several high-resolution structures of complex I from different species have been resolved. However, despite these significant achievements, the mechanism of redox-coupled proton pumping remains elusive. Here, we combined atomistic docking, molecular dynamics simulations and site-directed mutagenesis on respiratory complex I from Yarrowia lipolytica to identify a quinone (Q) binding site on its surface near the horizontal amphipathic helices of ND1 and NDUFS7 subunits. The surface-bound Q makes stable interactions with conserved charged and polar residues, including the highly conserved Arg72 from the NDUFS7 subunit. The binding and dynamics of a Q molecule at the surface-binding site raises interesting possibilities about the mechanism of complex I, which are discussed.
Collapse
Affiliation(s)
| | - Etienne Galemou Yoga
- Institute of Biochemistry II, University Hospital, Goethe University, Frankfurt am Main, Germany.,Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Aino Nyman
- Department of Physics, University of Helsinki, Finland
| | | | - Volker Zickermann
- Institute of Biochemistry II, University Hospital, Goethe University, Frankfurt am Main, Germany.,Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, Frankfurt am Main, Germany
| | - Outi Haapanen
- Department of Physics, University of Helsinki, Finland
| | - Vivek Sharma
- Department of Physics, University of Helsinki, Finland.,HiLIFE Institute of Biotechnology, University of Helsinki, Finland
| |
Collapse
|
19
|
Zhou L, Maldonado M, Padavannil A, Guo F, Letts JA. Structures of Tetrahymena's respiratory chain reveal the diversity of eukaryotic core metabolism. Science 2022; 376:831-839. [PMID: 35357889 DOI: 10.1126/science.abn7747] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Respiration is a core biological energy-converting process whose last steps are carried out by a chain of multi-subunit complexes in the inner mitochondrial membrane. To probe the functional and structural diversity of eukaryotic respiration, we examined the respiratory chain of the ciliate Tetrahymena thermophila (Tt). Using cryo-electron microscopy on a mixed sample, we solved structures of a supercomplex between Tt-complex I (CI) and Tt-CIII2 (Tt-SC I+III2) and a structure of Tt-CIV2. Tt-SC I+III2 (~2.3 MDa) is a curved assembly with structural and functional symmetry breaking. Tt-CIV2 is a ~2.7 MDa dimer with over 52 subunits per protomer, including mitochondrial carriers and a TIM83-TIM133-like domain. Our structural and functional study of the T. thermophila respiratory chain reveals divergence in key components of eukaryotic respiration, expanding our understanding of core metabolism.
Collapse
Affiliation(s)
- Long Zhou
- Department of Biophysics and Department of Critical Care Medicine of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - María Maldonado
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Abhilash Padavannil
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| | - Fei Guo
- BIOEM Facility, University of California, Davis, CA 95616, USA
| | - James A Letts
- Department of Molecular and Cellular Biology, University of California, Davis, CA 95616, USA
| |
Collapse
|
20
|
Grba DN, Blaza JN, Bridges HR, Agip ANA, Yin Z, Murai M, Miyoshi H, Hirst J. Cryo-electron microscopy reveals how acetogenins inhibit mitochondrial respiratory complex I. J Biol Chem 2022; 298:101602. [PMID: 35063503 PMCID: PMC8861642 DOI: 10.1016/j.jbc.2022.101602] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 12/22/2022] Open
Abstract
Mitochondrial complex I (NADH:ubiquinone oxidoreductase), a crucial enzyme in energy metabolism, captures the redox potential energy from NADH oxidation/ubiquinone reduction to create the proton motive force used to drive ATP synthesis in oxidative phosphorylation. High-resolution single-particle electron cryo-EM analyses have provided detailed structural knowledge of the catalytic machinery of complex I, but not of the molecular principles of its energy transduction mechanism. Although ubiquinone is considered to bind in a long channel at the interface of the membrane-embedded and hydrophilic domains, with channel residues likely involved in coupling substrate reduction to proton translocation, no structures with the channel fully occupied have yet been described. Here, we report the structure (determined by cryo-EM) of mouse complex I with a tight-binding natural product acetogenin inhibitor, which resembles the native substrate, bound along the full length of the expected ubiquinone-binding channel. Our structure reveals the mode of acetogenin binding and the molecular basis for structure-activity relationships within the acetogenin family. It also shows that acetogenins are such potent inhibitors because they are highly hydrophobic molecules that contain two specific hydrophilic moieties spaced to lock into two hydrophilic regions of the otherwise hydrophobic channel. The central hydrophilic section of the channel does not favor binding of the isoprenoid chain when the native substrate is fully bound but stabilizes the ubiquinone/ubiquinol headgroup as it transits to/from the active site. Therefore, the amphipathic nature of the channel supports both tight binding of the amphipathic inhibitor and rapid exchange of the ubiquinone/ubiquinol substrate and product.
Collapse
Affiliation(s)
- Daniel N Grba
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - James N Blaza
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Hannah R Bridges
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Ahmed-Noor A Agip
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Zhan Yin
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Masatoshi Murai
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Hideto Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Judy Hirst
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
| |
Collapse
|
21
|
Kühlbrandt W. Forty years in cryoEM of membrane proteins. Microscopy (Oxf) 2022; 71:i30-i50. [PMID: 35275191 PMCID: PMC8855526 DOI: 10.1093/jmicro/dfab041] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/05/2021] [Accepted: 11/10/2021] [Indexed: 12/13/2022] Open
Abstract
In a surprisingly short time, electron cryo-microscopy (cryoEM) has developed from a niche technique in structural biology to a mainstream method practiced in a rapidly growing number of laboratories around the world. From its beginnings about 40 years ago, cryoEM has had a major impact on the study of membrane proteins, in particular the energy-converting systems from bacterial, mitochondrial and chloroplast membranes. Early work on two-dimensional crystals attained resolutions ∼3.5 Å, but at present, single-particle cryoEM delivers much more detailed structures without crystals. Electron cryo-tomography of membranes and membrane-associated proteins adds valuable context, usually at lower resolution. The review ends with a brief outlook on future prospects.
Collapse
Affiliation(s)
- Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, Frankfurt am Main 60438, Germany
| |
Collapse
|
22
|
Vercellino I, Sazanov LA. The assembly, regulation and function of the mitochondrial respiratory chain. Nat Rev Mol Cell Biol 2022; 23:141-161. [PMID: 34621061 DOI: 10.1038/s41580-021-00415-0] [Citation(s) in RCA: 268] [Impact Index Per Article: 134.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/13/2021] [Indexed: 02/08/2023]
Abstract
The mitochondrial oxidative phosphorylation system is central to cellular metabolism. It comprises five enzymatic complexes and two mobile electron carriers that work in a mitochondrial respiratory chain. By coupling the oxidation of reducing equivalents coming into mitochondria to the generation and subsequent dissipation of a proton gradient across the inner mitochondrial membrane, this electron transport chain drives the production of ATP, which is then used as a primary energy carrier in virtually all cellular processes. Minimal perturbations of the respiratory chain activity are linked to diseases; therefore, it is necessary to understand how these complexes are assembled and regulated and how they function. In this Review, we outline the latest assembly models for each individual complex, and we also highlight the recent discoveries indicating that the formation of larger assemblies, known as respiratory supercomplexes, originates from the association of the intermediates of individual complexes. We then discuss how recent cryo-electron microscopy structures have been key to answering open questions on the function of the electron transport chain in mitochondrial respiration and how supercomplexes and other factors, including metabolites, can regulate the activity of the single complexes. When relevant, we discuss how these mechanisms contribute to physiology and outline their deregulation in human diseases.
Collapse
Affiliation(s)
- Irene Vercellino
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Leonid A Sazanov
- Institute of Science and Technology Austria, Klosterneuburg, Austria.
| |
Collapse
|
23
|
Parey K, Lasham J, Mills DJ, Djurabekova A, Haapanen O, Yoga EG, Xie H, Kühlbrandt W, Sharma V, Vonck J, Zickermann V. High-resolution structure and dynamics of mitochondrial complex I-Insights into the proton pumping mechanism. SCIENCE ADVANCES 2021; 7:eabj3221. [PMID: 34767441 PMCID: PMC8589321 DOI: 10.1126/sciadv.abj3221] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/24/2021] [Indexed: 05/23/2023]
Abstract
Mitochondrial NADH:ubiquinone oxidoreductase (complex I) is a 1-MDa membrane protein complex with a central role in energy metabolism. Redox-driven proton translocation by complex I contributes substantially to the proton motive force that drives ATP synthase. Several structures of complex I from bacteria and mitochondria have been determined, but its catalytic mechanism has remained controversial. We here present the cryo-EM structure of complex I from Yarrowia lipolytica at 2.1-Å resolution, which reveals the positions of more than 1600 protein-bound water molecules, of which ~100 are located in putative proton translocation pathways. Another structure of the same complex under steady-state activity conditions at 3.4-Å resolution indicates conformational transitions that we associate with proton injection into the central hydrophilic axis. By combining high-resolution structural data with site-directed mutagenesis and large-scale molecular dynamic simulations, we define details of the proton translocation pathways and offer insights into the redox-coupled proton pumping mechanism of complex I.
Collapse
Affiliation(s)
- Kristian Parey
- Institute of Biochemistry II, University Hospital, Goethe University, 60590 Frankfurt am Main, Germany
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
- Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, 60438 Frankfurt am Main, Germany
| | - Jonathan Lasham
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland
| | - Deryck J. Mills
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Amina Djurabekova
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland
| | - Outi Haapanen
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland
| | - Etienne Galemou Yoga
- Institute of Biochemistry II, University Hospital, Goethe University, 60590 Frankfurt am Main, Germany
- Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, 60438 Frankfurt am Main, Germany
| | - Hao Xie
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Vivek Sharma
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland
- HiLIFE Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Janet Vonck
- Department of Structural Biology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Volker Zickermann
- Institute of Biochemistry II, University Hospital, Goethe University, 60590 Frankfurt am Main, Germany
- Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, 60438 Frankfurt am Main, Germany
| |
Collapse
|
24
|
Lento C, Wilson DJ. Subsecond Time-Resolved Mass Spectrometry in Dynamic Structural Biology. Chem Rev 2021; 122:7624-7646. [PMID: 34324314 DOI: 10.1021/acs.chemrev.1c00222] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Life at the molecular level is a dynamic world, where the key players-proteins, oligonucleotides, lipids, and carbohydrates-are in a perpetual state of structural flux, shifting rapidly between local minima on their conformational free energy landscapes. The techniques of classical structural biology, X-ray crystallography, structural NMR, and cryo-electron microscopy (cryo-EM), while capable of extraordinary structural resolution, are innately ill-suited to characterize biomolecules in their dynamically active states. Subsecond time-resolved mass spectrometry (MS) provides a unique window into the dynamic world of biological macromolecules, offering the capacity to directly monitor biochemical processes and conformational shifts with a structural dimension provided by the electrospray charge-state distribution, ion mobility, covalent labeling, or hydrogen-deuterium exchange. Over the past two decades, this suite of techniques has provided important insights into the inherently dynamic processes that drive function and pathogenesis in biological macromolecules, including (mis)folding, complexation, aggregation, ligand binding, and enzyme catalysis, among others. This Review provides a comprehensive account of subsecond time-resolved MS and the advances it has enabled in dynamic structural biology, with an emphasis on insights into the dynamic drivers of protein function.
Collapse
Affiliation(s)
- Cristina Lento
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Derek J Wilson
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Klusch N, Senkler J, Yildiz Ö, Kühlbrandt W, Braun HP. A ferredoxin bridge connects the two arms of plant mitochondrial complex I. THE PLANT CELL 2021; 33:2072-2091. [PMID: 33768254 PMCID: PMC8290278 DOI: 10.1093/plcell/koab092] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/19/2021] [Indexed: 05/23/2023]
Abstract
Mitochondrial complex I is the main site for electron transfer to the respiratory chain and generates much of the proton gradient across the inner mitochondrial membrane. Complex I is composed of two arms, which form a conserved L-shape. We report the structures of the intact, 47-subunit mitochondrial complex I from Arabidopsis thaliana and the 51-subunit complex I from the green alga Polytomella sp., both at around 2.9 Å resolution. In both complexes, a heterotrimeric γ-carbonic anhydrase domain is attached to the membrane arm on the matrix side. Two states are resolved in A. thaliana complex I, with different angles between the two arms and different conformations of the ND1 (NADH dehydrogenase subunit 1) loop near the quinol binding site. The angle appears to depend on a bridge domain, which links the peripheral arm to the membrane arm and includes an unusual ferredoxin. We propose that the bridge domain participates in regulating the activity of plant complex I.
Collapse
Affiliation(s)
- Niklas Klusch
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Jennifer Senkler
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Hannover 30419, Germany
| | - Özkan Yildiz
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max-Planck-Institute of Biophysics, Frankfurt 60438, Germany
| | - Hans-Peter Braun
- Institut für Pflanzengenetik, Leibniz Universität Hannover, Hannover 30419, Germany
| |
Collapse
|
27
|
Abstract
The electron transport chain of mitochondria is initiated by the respiratory complex I that converts chemical energy into a proton motive force to power synthesis of adenosine triphosphate. On a chemical level, complex I catalyzes elementary electron and proton transfer processes that couple across large molecular distances of >300 Å. However, under low oxygen concentrations, the respiratory chain operates in reverse mode and produces harmful reactive oxygen species. To avoid cell damage, the mitochondrial complex I transitions into a deactive state that inhibits turnover by molecular principles that remain elusive. By combining large-scale molecular simulations with cryo-electron microscopy data, we show here that complex I deactivation blocks the communication between proton pumping and redox modules by conformational and hydration changes. Cellular respiration is powered by membrane-bound redox enzymes that convert chemical energy into an electrochemical proton gradient and drive the energy metabolism. By combining large-scale classical and quantum mechanical simulations with cryo-electron microscopy data, we resolve here molecular details of conformational changes linked to proton pumping in the mammalian complex I. Our data suggest that complex I deactivation blocks water-mediated proton transfer between a membrane-bound quinone site and proton-pumping modules, decoupling the energy-transduction machinery. We identify a putative gating region at the interface between membrane domain subunits ND1 and ND3/ND4L/ND6 that modulates the proton transfer by conformational changes in transmembrane helices and bulky residues. The region is perturbed by mutations linked to human mitochondrial disorders and is suggested to also undergo conformational changes during catalysis of simpler complex I variants that lack the “active”-to-“deactive” transition. Our findings suggest that conformational changes in transmembrane helices modulate the proton transfer dynamics by wetting/dewetting transitions and provide important functional insight into the mammalian respiratory complex I.
Collapse
|
28
|
Accessory Subunits of the Matrix Arm of Mitochondrial Complex I with a Focus on Subunit NDUFS4 and Its Role in Complex I Function and Assembly. Life (Basel) 2021; 11:life11050455. [PMID: 34069703 PMCID: PMC8161149 DOI: 10.3390/life11050455] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 12/19/2022] Open
Abstract
NADH:ubiquinone-oxidoreductase (complex I) is the largest membrane protein complex of the respiratory chain. Complex I couples electron transfer to vectorial proton translocation across the inner mitochondrial membrane. The L shaped structure of complex I is divided into a membrane arm and a matrix arm. Fourteen central subunits are conserved throughout species, while some 30 accessory subunits are typically found in eukaryotes. Complex I dysfunction is associated with mutations in the nuclear and mitochondrial genome, resulting in a broad spectrum of neuromuscular and neurodegenerative diseases. Accessory subunit NDUFS4 in the matrix arm is a hot spot for mutations causing Leigh or Leigh-like syndrome. In this review, we focus on accessory subunits of the matrix arm and discuss recent reports on the function of accessory subunit NDUFS4 and its interplay with NDUFS6, NDUFA12, and assembly factor NDUFAF2 in complex I assembly.
Collapse
|
29
|
Galemou Yoga E, Schiller J, Zickermann V. Ubiquinone Binding and Reduction by Complex I-Open Questions and Mechanistic Implications. Front Chem 2021; 9:672851. [PMID: 33996767 PMCID: PMC8119997 DOI: 10.3389/fchem.2021.672851] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
NADH: ubiquinone oxidoreductase (complex I) is the first enzyme complex of the respiratory chain. Complex I is a redox-driven proton pump that contributes to the proton motive force that drives ATP synthase. The structure of complex I has been analyzed by x-ray crystallography and electron cryo-microscopy and is now well-described. The ubiquinone (Q) reduction site of complex I is buried in the peripheral arm and a tunnel-like structure is thought to provide access for the hydrophobic substrate from the membrane. Several intermediate binding positions for Q in the tunnel were identified in molecular simulations. Structural data showed the binding of native Q molecules and short chain analogs and inhibitors in the access pathway and in the Q reduction site, respectively. We here review the current knowledge on the interaction of complex I with Q and discuss recent hypothetical models for the coupling mechanism.
Collapse
Affiliation(s)
- Etienne Galemou Yoga
- Institute of Biochemistry II, University Hospital, Goethe University, Frankfurt, Germany.,Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, Frankfurt, Germany
| | - Jonathan Schiller
- Institute of Biochemistry II, University Hospital, Goethe University, Frankfurt, Germany.,Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, Frankfurt, Germany
| | - Volker Zickermann
- Institute of Biochemistry II, University Hospital, Goethe University, Frankfurt, Germany.,Centre for Biomolecular Magnetic Resonance, Institute for Biophysical Chemistry, Goethe University, Frankfurt, Germany
| |
Collapse
|
30
|
Jarman OD, Biner O, Wright JJ, Hirst J. Paracoccus denitrificans: a genetically tractable model system for studying respiratory complex I. Sci Rep 2021; 11:10143. [PMID: 33980947 PMCID: PMC8115037 DOI: 10.1038/s41598-021-89575-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 04/27/2021] [Indexed: 02/03/2023] Open
Abstract
Mitochondrial complex I (NADH:ubiquinone oxidoreductase) is a crucial metabolic enzyme that couples the free energy released from NADH oxidation and ubiquinone reduction to the translocation of four protons across the inner mitochondrial membrane, creating the proton motive force for ATP synthesis. The mechanism by which the energy is captured, and the mechanism and pathways of proton pumping, remain elusive despite recent advances in structural knowledge. Progress has been limited by a lack of model systems able to combine functional and structural analyses with targeted mutagenic interrogation throughout the entire complex. Here, we develop and present the α-proteobacterium Paracoccus denitrificans as a suitable bacterial model system for mitochondrial complex I. First, we develop a robust purification protocol to isolate highly active complex I by introducing a His6-tag on the Nqo5 subunit. Then, we optimize the reconstitution of the enzyme into liposomes, demonstrating its proton pumping activity. Finally, we develop a strain of P. denitrificans that is amenable to complex I mutagenesis and create a catalytically inactive variant of the enzyme. Our model provides new opportunities to disentangle the mechanism of complex I by combining mutagenesis in every subunit with established interrogative biophysical measurements on both the soluble and membrane bound enzymes.
Collapse
Affiliation(s)
- Owen D. Jarman
- grid.5335.00000000121885934The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY UK
| | - Olivier Biner
- grid.5335.00000000121885934The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY UK
| | - John J. Wright
- grid.5335.00000000121885934The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY UK
| | - Judy Hirst
- grid.5335.00000000121885934The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, The Keith Peters Building, Cambridge Biomedical Campus, Hills Road, Cambridge, CB2 0XY UK
| |
Collapse
|
31
|
Yu H, Schut GJ, Haja DK, Adams MWW, Li H. Evolution of complex I-like respiratory complexes. J Biol Chem 2021; 296:100740. [PMID: 33957129 PMCID: PMC8165549 DOI: 10.1016/j.jbc.2021.100740] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 04/28/2021] [Accepted: 04/30/2021] [Indexed: 11/06/2022] Open
Abstract
The modern-day respiratory complex I shares a common ancestor with the membrane-bound hydrogenase (MBH) and membrane-bound sulfane sulfur reductase (MBS). MBH and MBS use protons and sulfur as their respective electron sinks, which helped to conserve energy during early life in the Proterozoic era when the Earth's atmosphere was low in oxygen. MBH and MBS likely evolved from an integration of an ancestral, membrane-embedded, multiple resistance and pH antiporter and a soluble redox-active module encompassing a [NiFe] hydrogenase. In this review, we discuss how the structures of MBH, MBS, multiple resistance and pH, photosynthetic NADH dehydrogenase-like complex type-1, and complex I, which have been determined recently, thanks to the advent of high-resolution cryo-EM, have significantly improved our understanding of the catalytic reaction mechanisms and the evolutionary relationships of the respiratory complexes.
Collapse
Affiliation(s)
- Hongjun Yu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Gerrit J Schut
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Domink K Haja
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Michael W W Adams
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA.
| | - Huilin Li
- Department of Structural Biology, Van Andel Institute, Grand Rapids, Michigan, USA.
| |
Collapse
|
32
|
Kell DB. A protet-based, protonic charge transfer model of energy coupling in oxidative and photosynthetic phosphorylation. Adv Microb Physiol 2021; 78:1-177. [PMID: 34147184 DOI: 10.1016/bs.ampbs.2021.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Textbooks of biochemistry will explain that the otherwise endergonic reactions of ATP synthesis can be driven by the exergonic reactions of respiratory electron transport, and that these two half-reactions are catalyzed by protein complexes embedded in the same, closed membrane. These views are correct. The textbooks also state that, according to the chemiosmotic coupling hypothesis, a (or the) kinetically and thermodynamically competent intermediate linking the two half-reactions is the electrochemical difference of protons that is in equilibrium with that between the two bulk phases that the coupling membrane serves to separate. This gradient consists of a membrane potential term Δψ and a pH gradient term ΔpH, and is known colloquially as the protonmotive force or pmf. Artificial imposition of a pmf can drive phosphorylation, but only if the pmf exceeds some 150-170mV; to achieve in vivo rates the imposed pmf must reach 200mV. The key question then is 'does the pmf generated by electron transport exceed 200mV, or even 170mV?' The possibly surprising answer, from a great many kinds of experiment and sources of evidence, including direct measurements with microelectrodes, indicates it that it does not. Observable pH changes driven by electron transport are real, and they control various processes; however, compensating ion movements restrict the Δψ component to low values. A protet-based model, that I outline here, can account for all the necessary observations, including all of those inconsistent with chemiosmotic coupling, and provides for a variety of testable hypotheses by which it might be refined.
Collapse
Affiliation(s)
- Douglas B Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative, Biology, University of Liverpool, Liverpool, United Kingdom; The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
| |
Collapse
|
33
|
A conserved arginine residue is critical for stabilizing the N2 FeS cluster in mitochondrial complex I. J Biol Chem 2021; 296:100474. [PMID: 33640456 PMCID: PMC8042128 DOI: 10.1016/j.jbc.2021.100474] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/18/2021] [Accepted: 02/24/2021] [Indexed: 11/22/2022] Open
Abstract
Respiratory complex I (NADH:ubiquinone oxidoreductase), the first enzyme of the electron-transport chain, captures the free energy released by NADH oxidation and ubiquinone reduction to translocate protons across an energy-transducing membrane and drive ATP synthesis during oxidative phosphorylation. The cofactor that transfers the electrons directly to ubiquinone is an iron–sulfur cluster (N2) located in the NDUFS2/NUCM subunit. A nearby arginine residue (R121), which forms part of the second coordination sphere of the N2 cluster, is known to be posttranslationally dimethylated but its functional and structural significance are not known. Here, we show that mutations of this arginine residue (R121M/K) abolish the quinone-reductase activity, concomitant with disappearance of the N2 signature from the electron paramagnetic resonance (EPR) spectrum. Analysis of the cryo-EM structure of NDUFS2-R121M complex I at 3.7 Å resolution identified the absence of the cubane N2 cluster as the cause of the dysfunction, within an otherwise intact enzyme. The mutation further induced localized disorder in nearby elements of the quinone-binding site, consistent with the close connections between the cluster and substrate-binding regions. Our results demonstrate that R121 is required for the formation and/or stability of the N2 cluster and highlight the importance of structural analyses for mechanistic interpretation of biochemical and spectroscopic data on complex I variants.
Collapse
|
34
|
Mamaev D, Zvyagilskaya R. Yarrowia lipolytica: a multitalented yeast species of ecological significance. FEMS Yeast Res 2021; 21:6141120. [PMID: 33595651 DOI: 10.1093/femsyr/foab008] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 02/13/2021] [Indexed: 02/07/2023] Open
Abstract
Yarrowia lipolytica is characterized by GRAS (Generally regarded as safe) status, the versatile substrate utilization profile, rapid utilization rates, metabolic diversity and flexibility, the unique abilities to tolerate to extreme environments (acidic, alkaline, hypersaline, heavy metal-pollutions and others) and elevated biosynthesis and secreting capacities. These advantages of Y. lipolytica allow us to consider it as having great ecological significance. Unfortunately, there is still a paucity of relevant review data. This mini-review highlights ecological ubiquity of Y. lipolytica species, their ability to diversify and colonize specialized niches. Different Y. lipolytica strains, native and engineered, are beneficial in degrading many environmental pollutants causing serious ecological problems worldwide. In agriculture has a potential to be a bio-control agent by stimulating plant defense response, and an eco-friendly bio-fertilizer. Engineered strains of Y. lipolytica have become a very promising platform for eco-friendly production of biofuel, commodities, chemicals and secondary metabolites of plant origin, obtaining which by other method were limited or economically infeasible, or were accompanied by stringent environmental problems. Perspectives to use potential of Y. lipolytica's capacities for industrial scale production of valuable compounds in an eco-friendly manner are proposed.
Collapse
Affiliation(s)
- Dmitry Mamaev
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., Moscow 119071, Russian Federation
| | - Renata Zvyagilskaya
- Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., Moscow 119071, Russian Federation
| |
Collapse
|
35
|
Correia SP, Moedas MF, Naess K, Bruhn H, Maffezzini C, Calvo-Garrido J, Lesko N, Wibom R, Schober FA, Jemt A, Stranneheim H, Freyer C, Wedell A, Wredenberg A. Severe congenital lactic acidosis and hypertrophic cardiomyopathy caused by an intronic variant in NDUFB7. Hum Mutat 2021; 42:378-384. [PMID: 33502047 DOI: 10.1002/humu.24173] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/18/2020] [Accepted: 01/24/2021] [Indexed: 01/18/2023]
Abstract
Mutations in structural subunits and assembly factors of complex I of the oxidative phosphorylation system constitute the most common cause of mitochondrial respiratory chain defects. Such mutations can present a wide range of clinical manifestations, varying from mild deficiencies to severe, lethal disorders. We describe a patient presenting intrauterine growth restriction and anemia, which displayed postpartum hypertrophic cardiomyopathy, lactic acidosis, encephalopathy, and a severe complex I defect with fatal outcome. Whole genome sequencing revealed an intronic biallelic mutation in the NDUFB7 gene (c.113-10C>G) and splicing pattern alterations in NDUFB7 messenger RNA were confirmed by RNA Sequencing. The detected variant resulted in a significant reduction of the NDUFB7 protein and reduced complex I activity. Complementation studies with expression of wild-type NDUFB7 in patient fibroblasts normalized complex I function. Here we report a case with a primary complex I defect due to a homozygous mutation in an intron region of the NDUFB7 gene.
Collapse
Affiliation(s)
- Sandrina P Correia
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Marco F Moedas
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Karin Naess
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Helene Bruhn
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Camilla Maffezzini
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Javier Calvo-Garrido
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Nicole Lesko
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Rolf Wibom
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Florian A Schober
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Anders Jemt
- Department of Microbiology, Tumour and Cell Biology, Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Henrik Stranneheim
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Christoph Freyer
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Anna Wedell
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Anna Wredenberg
- Centre for Inherited Metabolic Diseases, Karolinska University Hospital, Stockholm, Sweden.,Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.,Max Planck Institute Biology of Ageing - Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
36
|
Di Luca A, Kaila VRI. Molecular strain in the active/deactive-transition modulates domain coupling in respiratory complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148382. [PMID: 33513365 DOI: 10.1016/j.bbabio.2021.148382] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 01/08/2021] [Accepted: 01/21/2021] [Indexed: 12/14/2022]
Abstract
Complex I functions as a primary redox-driven proton pump in aerobic respiratory chains, establishing a proton motive force that powers ATP synthesis and active transport. Recent cryo-electron microscopy (cryo-EM) experiments have resolved the mammalian complex I in the biomedically relevant active (A) and deactive (D) states (Zhu et al., 2016; Fiedorczuk et al., 2016; Agip et al., 2018 [1-3]) that could regulate enzyme turnover, but it still remains unclear how the conformational state and activity are linked. We show here how global motion along the A/D transition accumulates molecular strain at specific coupling regions important for both redox chemistry and proton pumping. Our data suggest that the A/D motion modulates force propagation pathways between the substrate-binding site and the proton pumping machinery that could alter electrostatic and conformational coupling across large distances. Our findings provide a molecular basis to understand how global protein dynamics can modulate the biological activity of large molecular complexes.
Collapse
Affiliation(s)
- Andrea Di Luca
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden
| | - Ville R I Kaila
- Department of Biochemistry and Biophysics, Stockholm University, 10691 Stockholm, Sweden.
| |
Collapse
|
37
|
Maldonado M, Guo F, Letts JA. Atomic structures of respiratory complex III 2, complex IV, and supercomplex III 2-IV from vascular plants. eLife 2021; 10:e62047. [PMID: 33463523 PMCID: PMC7815315 DOI: 10.7554/elife.62047] [Citation(s) in RCA: 116] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/25/2020] [Indexed: 12/11/2022] Open
Abstract
Mitochondrial complex III (CIII2) and complex IV (CIV), which can associate into a higher-order supercomplex (SC III2+IV), play key roles in respiration. However, structures of these plant complexes remain unknown. We present atomic models of CIII2, CIV, and SC III2+IV from Vigna radiata determined by single-particle cryoEM. The structures reveal plant-specific differences in the MPP domain of CIII2 and define the subunit composition of CIV. Conformational heterogeneity analysis of CIII2 revealed long-range, coordinated movements across the complex, as well as the motion of CIII2's iron-sulfur head domain. The CIV structure suggests that, in plants, proton translocation does not occur via the H channel. The supercomplex interface differs significantly from that in yeast and bacteria in its interacting subunits, angle of approach and limited interactions in the mitochondrial matrix. These structures challenge long-standing assumptions about the plant complexes and generate new mechanistic hypotheses.
Collapse
Affiliation(s)
- Maria Maldonado
- Department of Molecular and Cellular Biology, University of California DavisDavisUnited States
| | - Fei Guo
- Department of Molecular and Cellular Biology, University of California DavisDavisUnited States
- BIOEM Facility, University of California DavisDavisUnited States
| | - James A Letts
- Department of Molecular and Cellular Biology, University of California DavisDavisUnited States
| |
Collapse
|
38
|
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
|
39
|
Human Mitochondrial Pathologies of the Respiratory Chain and ATP Synthase: Contributions from Studies of Saccharomyces cerevisiae. Life (Basel) 2020; 10:life10110304. [PMID: 33238568 PMCID: PMC7700678 DOI: 10.3390/life10110304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 12/14/2022] Open
Abstract
The ease with which the unicellular yeast Saccharomyces cerevisiae can be manipulated genetically and biochemically has established this organism as a good model for the study of human mitochondrial diseases. The combined use of biochemical and molecular genetic tools has been instrumental in elucidating the functions of numerous yeast nuclear gene products with human homologs that affect a large number of metabolic and biological processes, including those housed in mitochondria. These include structural and catalytic subunits of enzymes and protein factors that impinge on the biogenesis of the respiratory chain. This article will review what is currently known about the genetics and clinical phenotypes of mitochondrial diseases of the respiratory chain and ATP synthase, with special emphasis on the contribution of information gained from pet mutants with mutations in nuclear genes that impair mitochondrial respiration. Our intent is to provide the yeast mitochondrial specialist with basic knowledge of human mitochondrial pathologies and the human specialist with information on how genes that directly and indirectly affect respiration were identified and characterized in yeast.
Collapse
|
40
|
Xu Y, Xue D, Bankhead A, Neamati N. Why All the Fuss about Oxidative Phosphorylation (OXPHOS)? J Med Chem 2020; 63:14276-14307. [PMID: 33103432 DOI: 10.1021/acs.jmedchem.0c01013] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Certain subtypes of cancer cells require oxidative phosphorylation (OXPHOS) to survive. Increased OXPHOS dependency is frequently a hallmark of cancer stem cells and cells resistant to chemotherapy and targeted therapies. Suppressing the OXPHOS function might also influence the tumor microenvironment by alleviating hypoxia and improving the antitumor immune response. Thus, targeting OXPHOS is a promising strategy to treat various cancers. A growing arsenal of therapeutic agents is under development to inhibit this biological process. This Perspective provides an overview of the structure and function of OXPHOS complexes, their biological functions in cancer, relevant research tools and models, as well as the limitations of OXPHOS as drug targets. We also focus on the current development status of OXPHOS inhibitors and potential therapeutic strategies to strengthen their clinical applications.
Collapse
Affiliation(s)
- Yibin Xu
- Department of Medicinal Chemistry, College of Pharmacy, Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ding Xue
- Department of Medicinal Chemistry, College of Pharmacy, Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Armand Bankhead
- Department of Computational Medicine and Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan 48109, United States.,Department of Biostatistics, University of Michigan, School of Public Health, Ann Arbor, Michigan 48109, United States
| | - Nouri Neamati
- Department of Medicinal Chemistry, College of Pharmacy, Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
41
|
Specific features and assembly of the plant mitochondrial complex I revealed by cryo-EM. Nat Commun 2020; 11:5195. [PMID: 33060577 PMCID: PMC7567890 DOI: 10.1038/s41467-020-18814-w] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 09/09/2020] [Indexed: 02/01/2023] Open
Abstract
Mitochondria are the powerhouses of eukaryotic cells and the site of essential metabolic reactions. Complex I or NADH:ubiquinone oxidoreductase is the main entry site for electrons into the mitochondrial respiratory chain and constitutes the largest of the respiratory complexes. Its structure and composition vary across eukaryote species. However, high resolution structures are available only for one group of eukaryotes, opisthokonts. In plants, only biochemical studies were carried out, already hinting at the peculiar composition of complex I in the green lineage. Here, we report several cryo-electron microscopy structures of the plant mitochondrial complex I. We describe the structure and composition of the plant respiratory complex I, including the ancestral mitochondrial domain composed of the carbonic anhydrase. We show that the carbonic anhydrase is a heterotrimeric complex with only one conserved active site. This domain is crucial for the overall stability of complex I as well as a peculiar lipid complex composed of cardiolipin and phosphatidylinositols. Moreover, we also describe the structure of one of the plant-specific complex I assembly intermediates, lacking the whole PD module, in presence of the maturation factor GLDH. GLDH prevents the binding of the plant specific P1 protein, responsible for the linkage of the PP to the PD module.
Collapse
|
42
|
Green JC, Jiang Y, He L, Xu Y, Sun D, Keoprasert T, Nelson C, Oh U, Lesnefsky EJ, Kellogg GE, Chen Q, Zhang S. Characterization and Discovery of a Selective Small-Molecule Modulator of Mitochondrial Complex I Targeting a Unique Binding Site. J Med Chem 2020; 63:11819-11830. [PMID: 32945676 DOI: 10.1021/acs.jmedchem.0c01021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mitochondrial dysfunction has been recognized as an essential contributor to many human diseases including neurodegenerative disorders. However, the exact pathological role of mitochondrial dysfunction, especially in mitochondrial reactive oxygen species-associated oxidative stress, remains elusive, partially due to the lack of chemical probes with well-defined mechanisms of action. Herein, we describe the characterization and discovery of a rationally designed small molecule ZCM-I-1 as a selective modulator of the production of reactive oxygen species from mitochondrial complex I that does not alter mitochondrial membrane potential and bioenergetics. Chemical biology studies employing photoaffinity probes derived from ZCM-I-1 demonstrated its novel mechanism of action of modulating complex I via interactions with the flavin mononucleotide site, proximal in the reaction pathway within complex I.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Edward J Lesnefsky
- Medical Service, McGuire Department of Veteran Affairs Medical Center, Richmond, Virginia 23224, United States
| | | | | | | |
Collapse
|
43
|
Grba DN, Hirst J. Mitochondrial complex I structure reveals ordered water molecules for catalysis and proton translocation. Nat Struct Mol Biol 2020; 27:892-900. [PMID: 32747785 PMCID: PMC7612091 DOI: 10.1038/s41594-020-0473-x] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/26/2020] [Indexed: 01/09/2023]
Abstract
Mitochondrial complex I powers ATP synthesis by oxidative phosphorylation, exploiting the energy from ubiquinone reduction by NADH to drive protons across the energy-transducing inner membrane. Recent cryo-EM analyses of mammalian and yeast complex I have revolutionized structural and mechanistic knowledge and defined structures in different functional states. Here, we describe a 2.7-Å-resolution structure of the 42-subunit complex I from the yeast Yarrowia lipolytica containing 275 structured water molecules. We identify a proton-relay pathway for ubiquinone reduction and water molecules that connect mechanistically crucial elements and constitute proton-translocation pathways through the membrane. By comparison with known structures, we deconvolute structural changes governing the mammalian 'deactive transition' (relevant to ischemia-reperfusion injury) and their effects on the ubiquinone-binding site and a connected cavity in ND1. Our structure thus provides important insights into catalysis by this enigmatic respiratory machine.
Collapse
Affiliation(s)
- Daniel N Grba
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Judy Hirst
- The Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
| |
Collapse
|
44
|
|
45
|
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.
Collapse
Affiliation(s)
- Domen Kampjut
- IST Austria, Am Campus 1, 3400 Klosterneuburg, Austria
| | | |
Collapse
|
46
|
Bornstein R, Gonzalez B, Johnson SC. Mitochondrial pathways in human health and aging. Mitochondrion 2020; 54:72-84. [PMID: 32738358 PMCID: PMC7508824 DOI: 10.1016/j.mito.2020.07.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 12/27/2022]
Abstract
Mitochondria are eukaryotic organelles known best for their roles in energy production and metabolism. While often thought of as simply the 'powerhouse of the cell,' these organelles participate in a variety of critical cellular processes including reactive oxygen species (ROS) production, regulation of programmed cell death, modulation of inter- and intracellular nutrient signaling pathways, and maintenance of cellular proteostasis. Disrupted mitochondrial function is a hallmark of eukaryotic aging, and mitochondrial dysfunction has been reported to play a role in many aging-related diseases. While mitochondria are major players in human diseases, significant questions remain regarding their precise mechanistic role. In this review, we detail mechanisms by which mitochondrial dysfunction participate in disease and aging based on findings from model organisms and human genetics studies.
Collapse
Affiliation(s)
| | - Brenda Gonzalez
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Simon C Johnson
- Department of Neurology, University of Washington, Seattle, WA, USA; Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA.
| |
Collapse
|
47
|
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.
Collapse
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
| |
Collapse
|
48
|
Gutiérrez-Fernández J, Kaszuba K, Minhas GS, Baradaran R, Tambalo M, Gallagher DT, Sazanov LA. Key role of quinone in the mechanism of respiratory complex I. Nat Commun 2020; 11:4135. [PMID: 32811817 PMCID: PMC7434922 DOI: 10.1038/s41467-020-17957-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 07/28/2020] [Indexed: 01/12/2023] Open
Abstract
Complex I is the first and the largest enzyme of respiratory chains in bacteria and mitochondria. The mechanism which couples spatially separated transfer of electrons to proton translocation in complex I is not known. Here we report five crystal structures of T. thermophilus enzyme in complex with NADH or quinone-like compounds. We also determined cryo-EM structures of major and minor native states of the complex, differing in the position of the peripheral arm. Crystal structures show that binding of quinone-like compounds (but not of NADH) leads to a related global conformational change, accompanied by local re-arrangements propagating from the quinone site to the nearest proton channel. Normal mode and molecular dynamics analyses indicate that these are likely to represent the first steps in the proton translocation mechanism. Our results suggest that quinone binding and chemistry play a key role in the coupling mechanism of complex I. Complex I (NADH:ubiquinone oxidoreductase) is the first enzyme of the respiratory chain in bacteria and mitochondria. Here, the authors present cryo-EM and crystal structures of T. thermophilus complex I in different conformational states and further analyse them by Normal Mode Analysis and molecular dynamics simulations and conclude that quinone redox reactions are important for the coupling mechanism of complex I.
Collapse
Affiliation(s)
| | - Karol Kaszuba
- Institute of Science and Technology Austria, Am Campus 1, A-3400, Klosterneuburg, Austria
| | - Gurdeep S Minhas
- Medical Research Council Mitochondrial Biology Unit, Keith Peters Building, Hills rd, Cambridge, CB2 0XY, UK.,Sosei Heptares, Steinmetz Building, Granta Park, Cambridge, CB21 6DG, UK
| | - Rozbeh Baradaran
- Medical Research Council Mitochondrial Biology Unit, Keith Peters Building, Hills rd, Cambridge, CB2 0XY, UK.,Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
| | - Margherita Tambalo
- Institute of Science and Technology Austria, Am Campus 1, A-3400, Klosterneuburg, Austria
| | - David T Gallagher
- Medical Research Council Mitochondrial Biology Unit, Keith Peters Building, Hills rd, Cambridge, CB2 0XY, UK
| | - Leonid A Sazanov
- Institute of Science and Technology Austria, Am Campus 1, A-3400, Klosterneuburg, Austria.
| |
Collapse
|
49
|
Haapanen O, Reidelbach M, Sharma V. Coupling of quinone dynamics to proton pumping in respiratory complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148287. [PMID: 32777307 DOI: 10.1016/j.bbabio.2020.148287] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 07/09/2020] [Accepted: 08/03/2020] [Indexed: 12/12/2022]
Abstract
Respiratory complex I (NADH:quinone oxidoreductase) plays a central role in generating the proton electrochemical gradient in mitochondrial and bacterial membranes, which is needed to generate ATP. Several high-resolution structures of complex I have been determined, revealing its intricate architecture and complementing the biochemical and biophysical studies. However, the molecular mechanism of long-range coupling between ubiquinone (Q) reduction and proton pumping is not known. Computer simulations have been applied to decipher the dynamics of Q molecule in the ~30 Å long Q tunnel. In this short report, we discuss the binding and dynamics of Q at computationally predicted Q binding sites, many of which are supported by structural data on complex I. We suggest that the binding of Q at these sites is coupled to proton pumping by means of conformational rearrangements in the conserved loops of core subunits.
Collapse
Affiliation(s)
- Outi Haapanen
- Department of Physics, University of Helsinki, Finland
| | | | - Vivek Sharma
- Department of Physics, University of Helsinki, Finland; HiLIFE Institute of Biotechnology, University of Helsinki, Finland.
| |
Collapse
|
50
|
Grivennikova VG, Gladyshev GV, Vinogradov AD. Deactivation of mitochondrial NADH:ubiquinone oxidoreductase (respiratory complex I): Extrinsically affecting factors. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148207. [DOI: 10.1016/j.bbabio.2020.148207] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 03/13/2020] [Accepted: 04/14/2020] [Indexed: 12/14/2022]
|