1
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Quinone binding sites of cyt bc complexes analysed by X-ray crystallography and cryogenic electron microscopy. Biochem Soc Trans 2022; 50:877-893. [PMID: 35356963 PMCID: PMC9162462 DOI: 10.1042/bst20190963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/06/2022] [Accepted: 03/11/2022] [Indexed: 11/17/2022]
Abstract
Cytochrome (cyt) bc1, bcc and b6f complexes, collectively referred to as cyt bc complexes, are homologous isoprenoid quinol oxidising enzymes present in diverse phylogenetic lineages. Cyt bc1 and bcc complexes are constituents of the electron transport chain (ETC) of cellular respiration, and cyt b6f complex is a component of the photosynthetic ETC. Cyt bc complexes share in general the same Mitchellian Q cycle mechanism, with which they accomplish proton translocation and thus contribute to the generation of proton motive force which drives ATP synthesis. They therefore require a quinol oxidation (Qo) and a quinone reduction (Qi) site. Yet, cyt bc complexes evolved to adapt to specific electrochemical properties of different quinone species and exhibit structural diversity. This review summarises structural information on native quinones and quinone-like inhibitors bound in cyt bc complexes resolved by X-ray crystallography and cryo-EM structures. Although the Qi site architecture of cyt bc1 complex and cyt bcc complex differs considerably, quinone molecules were resolved at the respective Qi sites in very similar distance to haem bH. In contrast, more diverse positions of native quinone molecules were resolved at Qo sites, suggesting multiple quinone binding positions or captured snapshots of trajectories toward the catalytic site. A wide spectrum of inhibitors resolved at Qo or Qi site covers fungicides, antimalarial and antituberculosis medications and drug candidates. The impact of these structures for characterising the Q cycle mechanism, as well as their relevance for the development of medications and agrochemicals are discussed.
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2
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Sarewicz M, Pintscher S, Pietras R, Borek A, Bujnowicz Ł, Hanke G, Cramer WA, Finazzi G, Osyczka A. Catalytic Reactions and Energy Conservation in the Cytochrome bc1 and b6f Complexes of Energy-Transducing Membranes. Chem Rev 2021; 121:2020-2108. [PMID: 33464892 PMCID: PMC7908018 DOI: 10.1021/acs.chemrev.0c00712] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Indexed: 12/16/2022]
Abstract
This review focuses on key components of respiratory and photosynthetic energy-transduction systems: the cytochrome bc1 and b6f (Cytbc1/b6f) membranous multisubunit homodimeric complexes. These remarkable molecular machines catalyze electron transfer from membranous quinones to water-soluble electron carriers (such as cytochromes c or plastocyanin), coupling electron flow to proton translocation across the energy-transducing membrane and contributing to the generation of a transmembrane electrochemical potential gradient, which powers cellular metabolism in the majority of living organisms. Cytsbc1/b6f share many similarities but also have significant differences. While decades of research have provided extensive knowledge on these enzymes, several important aspects of their molecular mechanisms remain to be elucidated. We summarize a broad range of structural, mechanistic, and physiological aspects required for function of Cytbc1/b6f, combining textbook fundamentals with new intriguing concepts that have emerged from more recent studies. The discussion covers but is not limited to (i) mechanisms of energy-conserving bifurcation of electron pathway and energy-wasting superoxide generation at the quinol oxidation site, (ii) the mechanism by which semiquinone is stabilized at the quinone reduction site, (iii) interactions with substrates and specific inhibitors, (iv) intermonomer electron transfer and the role of a dimeric complex, and (v) higher levels of organization and regulation that involve Cytsbc1/b6f. In addressing these topics, we point out existing uncertainties and controversies, which, as suggested, will drive further research in this field.
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Affiliation(s)
- Marcin Sarewicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Sebastian Pintscher
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Rafał Pietras
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Arkadiusz Borek
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Łukasz Bujnowicz
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Guy Hanke
- School
of Biological and Chemical Sciences, Queen
Mary University of London, London E1 4NS, U.K.
| | - William A. Cramer
- Department
of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 United States
| | - Giovanni Finazzi
- Laboratoire
de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National Recherche Scientifique,
Commissariat Energie Atomique et Energies Alternatives, Institut National
Recherche l’agriculture, l’alimentation et l’environnement, 38054 Grenoble Cedex 9, France
| | - Artur Osyczka
- Department
of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
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3
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Vos MH, Salman M, Ramodiharilafy R, Liebl U. Fluorescent iron‑sulfur centers: Photochemistry of the PetA Rieske protein from Aquifex aeolicus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148385. [PMID: 33516769 DOI: 10.1016/j.bbabio.2021.148385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 11/28/2022]
Abstract
Cytochrome bc1 complexes are energy-transducing enzymes and key components of respiratory electron chains. They contain Rieske 2Fe2S proteins that absorb very weakly in the visible absorption region compared to the heme cofactors of the cytochromes, but are known to yield photoproducts. Here, the photoreactions of isolated Rieske proteins from the hyperthermophilic bacterium Aquifex aeolicus are studied in two redox states using ultrafast transient fluorescence and absorption spectroscopy. We provide evidence, for the first time in iron‑sulfur proteins, of very weak fluorescence of the excited state, in the oxidized as well as the reduced state. The excited states of the oxidized and reduced forms decay in 1.5 ps and 30 ps, respectively. In both cases they give rise to product states with lifetimes beyond 1 ns, reflecting photo-reduction of oxidized centers as well as photo-oxidation of reduced centers. Potential reaction partners are discussed and studied using site-directed mutagenesis. For the reduced state, a nearby disulfide bridge is suggested as an electron acceptor. The resulting photoproducts in either state may play a role in photoactivation processes.
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Affiliation(s)
- Marten H Vos
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France.
| | - Mayla Salman
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Rivo Ramodiharilafy
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
| | - Ursula Liebl
- LOB, CNRS, INSERM, Ecole Polytechnique, Institut Polytechnique de Paris, 91128 Palaiseau Cedex, France
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4
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Melin F, Hellwig P. Redox Properties of the Membrane Proteins from the Respiratory Chain. Chem Rev 2020; 120:10244-10297. [DOI: 10.1021/acs.chemrev.0c00249] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Frederic Melin
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
| | - Petra Hellwig
- Chimie de la Matière Complexe UMR 7140, Laboratoire de Bioelectrochimie et Spectroscopie, CNRS-Université de Strasbourg, 1 rue Blaise Pascal, 67070 Strasbourg, France
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5
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Zhu G, Zeng H, Zhang S, Juli J, Pang X, Hoffmann J, Zhang Y, Morgner N, Zhu Y, Peng G, Michel H, Sun F. A 3.3 Å‐Resolution Structure of Hyperthermophilic Respiratory Complex III Reveals the Mechanism of Its Thermal Stability. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201911554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Guoliang Zhu
- National Laboratory of Biomacromolecules Institute of Biophysics (IBP) Chinese Academy of Sciences 15 Datun Road, Chaoyang District Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100101 China
| | - Hui Zeng
- Department of Molecular Membrane Biology Max Planck Institute of Biophysics Max-von Laue-Strasse 3 60438 Frankfurt am Main Germany
| | - Shuangbo Zhang
- National Laboratory of Biomacromolecules Institute of Biophysics (IBP) Chinese Academy of Sciences 15 Datun Road, Chaoyang District Beijing 100101 China
| | - Jana Juli
- Department of Molecular Membrane Biology Max Planck Institute of Biophysics Max-von Laue-Strasse 3 60438 Frankfurt am Main Germany
| | | | - Jan Hoffmann
- Institute of Physical and Theoretical Chemistry Goethe University Max-von Laue-Strasse 7 60438 Frankfurt am Main Germany
| | - Yan Zhang
- National Laboratory of Biomacromolecules Institute of Biophysics (IBP) Chinese Academy of Sciences 15 Datun Road, Chaoyang District Beijing 100101 China
| | - Nina Morgner
- Institute of Physical and Theoretical Chemistry Goethe University Max-von Laue-Strasse 7 60438 Frankfurt am Main Germany
| | - Yun Zhu
- National Laboratory of Biomacromolecules Institute of Biophysics (IBP) Chinese Academy of Sciences 15 Datun Road, Chaoyang District Beijing 100101 China
| | - Guohong Peng
- National Laboratory of Biomacromolecules Institute of Biophysics (IBP) Chinese Academy of Sciences 15 Datun Road, Chaoyang District Beijing 100101 China
- Department of Molecular Membrane Biology Max Planck Institute of Biophysics Max-von Laue-Strasse 3 60438 Frankfurt am Main Germany
| | - Hartmut Michel
- Department of Molecular Membrane Biology Max Planck Institute of Biophysics Max-von Laue-Strasse 3 60438 Frankfurt am Main Germany
| | - Fei Sun
- National Laboratory of Biomacromolecules Institute of Biophysics (IBP) Chinese Academy of Sciences 15 Datun Road, Chaoyang District Beijing 100101 China
- University of Chinese Academy of Sciences Beijing 100101 China
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6
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Zhu G, Zeng H, Zhang S, Juli J, Pang X, Hoffmann J, Zhang Y, Morgner N, Zhu Y, Peng G, Michel H, Sun F. A 3.3 Å-Resolution Structure of Hyperthermophilic Respiratory Complex III Reveals the Mechanism of Its Thermal Stability. Angew Chem Int Ed Engl 2020; 59:343-351. [PMID: 31778296 PMCID: PMC7004027 DOI: 10.1002/anie.201911554] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 11/06/2019] [Indexed: 01/01/2023]
Abstract
Respiratory chain complexes convert energy by coupling electron flow to transmembrane proton translocation. Owing to a lack of atomic structures of cytochrome bc1 complex (Complex III) from thermophilic bacteria, little is known about the adaptations of this macromolecular machine to hyperthermophilic environments. In this study, we purified the cytochrome bc1 complex of Aquifex aeolicus, one of the most extreme thermophilic bacteria known, and determined its structure with and without an inhibitor at 3.3 Å resolution. Several residues unique for thermophilic bacteria were detected that provide additional stabilization for the structure. An extra transmembrane helix at the N-terminus of cyt. c1 was found to greatly enhance the interaction between cyt. b and cyt. c1 , and to bind a phospholipid molecule to stabilize the complex in the membrane. These results provide the structural basis for the hyperstability of the cytochrome bc1 complex in an extreme thermal environment.
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Affiliation(s)
- Guoliang Zhu
- National Laboratory of BiomacromoleculesInstitute of Biophysics (IBP)Chinese Academy of Sciences15 Datun Road, Chaoyang DistrictBeijing100101China
- University of Chinese Academy of SciencesBeijing100101China
| | - Hui Zeng
- Department of Molecular Membrane BiologyMax Planck Institute of BiophysicsMax-von Laue-Strasse 360438Frankfurt am MainGermany
| | - Shuangbo Zhang
- National Laboratory of BiomacromoleculesInstitute of Biophysics (IBP)Chinese Academy of Sciences15 Datun Road, Chaoyang DistrictBeijing100101China
| | - Jana Juli
- Department of Molecular Membrane BiologyMax Planck Institute of BiophysicsMax-von Laue-Strasse 360438Frankfurt am MainGermany
| | | | - Jan Hoffmann
- Institute of Physical and Theoretical ChemistryGoethe UniversityMax-von Laue-Strasse 760438Frankfurt am MainGermany
| | - Yan Zhang
- National Laboratory of BiomacromoleculesInstitute of Biophysics (IBP)Chinese Academy of Sciences15 Datun Road, Chaoyang DistrictBeijing100101China
| | - Nina Morgner
- Institute of Physical and Theoretical ChemistryGoethe UniversityMax-von Laue-Strasse 760438Frankfurt am MainGermany
| | - Yun Zhu
- National Laboratory of BiomacromoleculesInstitute of Biophysics (IBP)Chinese Academy of Sciences15 Datun Road, Chaoyang DistrictBeijing100101China
| | - Guohong Peng
- National Laboratory of BiomacromoleculesInstitute of Biophysics (IBP)Chinese Academy of Sciences15 Datun Road, Chaoyang DistrictBeijing100101China
- Department of Molecular Membrane BiologyMax Planck Institute of BiophysicsMax-von Laue-Strasse 360438Frankfurt am MainGermany
| | - Hartmut Michel
- Department of Molecular Membrane BiologyMax Planck Institute of BiophysicsMax-von Laue-Strasse 360438Frankfurt am MainGermany
| | - Fei Sun
- National Laboratory of BiomacromoleculesInstitute of Biophysics (IBP)Chinese Academy of Sciences15 Datun Road, Chaoyang DistrictBeijing100101China
- University of Chinese Academy of SciencesBeijing100101China
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7
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Refojo PN, Sena FV, Calisto F, Sousa FM, Pereira MM. The plethora of membrane respiratory chains in the phyla of life. Adv Microb Physiol 2019; 74:331-414. [PMID: 31126533 DOI: 10.1016/bs.ampbs.2019.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The diversity of microbial cells is reflected in differences in cell size and shape, motility, mechanisms of cell division, pathogenicity or adaptation to different environmental niches. All these variations are achieved by the distinct metabolic strategies adopted by the organisms. The respiratory chains are integral parts of those strategies especially because they perform the most or, at least, most efficient energy conservation in the cell. Respiratory chains are composed of several membrane proteins, which perform a stepwise oxidation of metabolites toward the reduction of terminal electron acceptors. Many of these membrane proteins use the energy released from the oxidoreduction reaction they catalyze to translocate charges across the membrane and thus contribute to the establishment of the membrane potential, i.e. they conserve energy. In this work we illustrate and discuss the composition of the respiratory chains of different taxonomic clades, based on bioinformatic analyses and on biochemical data available in the literature. We explore the diversity of the respiratory chains of Animals, Plants, Fungi and Protists kingdoms as well as of Prokaryotes, including Bacteria and Archaea. The prokaryotic phyla studied in this work are Gammaproteobacteria, Betaproteobacteria, Epsilonproteobacteria, Deltaproteobacteria, Alphaproteobacteria, Firmicutes, Actinobacteria, Chlamydiae, Verrucomicrobia, Acidobacteria, Planctomycetes, Cyanobacteria, Bacteroidetes, Chloroflexi, Deinococcus-Thermus, Aquificae, Thermotogae, Deferribacteres, Nitrospirae, Euryarchaeota, Crenarchaeota and Thaumarchaeota.
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Affiliation(s)
- Patrícia N Refojo
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Filipa V Sena
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Filipa Calisto
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Filipe M Sousa
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157, Oeiras, Portugal; University of Lisboa, Faculty of Sciences, BIOISI- Biosystems & Integrative Sciences Institute, Lisboa, Portugal
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8
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From low- to high-potential bioenergetic chains: Thermodynamic constraints of Q-cycle function. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1569-1579. [DOI: 10.1016/j.bbabio.2016.06.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/14/2016] [Accepted: 06/16/2016] [Indexed: 11/27/2022]
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9
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Boughanemi S, Lyonnet J, Infossi P, Bauzan M, Kosta A, Lignon S, Giudici-Orticoni MT, Guiral M. Microbial oxidative sulfur metabolism: biochemical evidence of the membrane-bound heterodisulfide reductase-like complex of the bacteriumAquifex aeolicus. FEMS Microbiol Lett 2016; 363:fnw156. [DOI: 10.1093/femsle/fnw156] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2016] [Indexed: 11/13/2022] Open
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10
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Degli Esposti M. Genome Analysis of Structure-Function Relationships in Respiratory Complex I, an Ancient Bioenergetic Enzyme. Genome Biol Evol 2015; 8:126-47. [PMID: 26615219 PMCID: PMC4758237 DOI: 10.1093/gbe/evv239] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Respiratory complex I (NADH:ubiquinone oxidoreductase) is a ubiquitous bioenergetic enzyme formed by over 40 subunits in eukaryotes and a minimum of 11 subunits in bacteria. Recently, crystal structures have greatly advanced our knowledge of complex I but have not clarified the details of its reaction with ubiquinone (Q). This reaction is essential for bioenergy production and takes place in a large cavity embedded within a conserved module that is homologous to the catalytic core of Ni-Fe hydrogenases. However, how a hydrogenase core has evolved into the protonmotive Q reductase module of complex I has remained unclear. This work has exploited the abundant genomic information that is currently available to deduce structure-function relationships in complex I that indicate the evolutionary steps of Q reactivity and its adaptation to natural Q substrates. The results provide answers to fundamental questions regarding various aspects of complex I reaction with Q and help re-defining the old concept that this reaction may involve two Q or inhibitor sites. The re-definition leads to a simplified classification of the plethora of complex I inhibitors while throwing a new light on the evolution of the enzyme function.
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Affiliation(s)
- Mauro Degli Esposti
- Italian Institute of Technology, Genova, Italy Center for Genomic Sciences, UNAM, Cuernavaca, Mexico
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11
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Brink FT, Baymann F. Rieske/Cytochrome b Complexes: The Turbo Chargers of Chemiosmosis. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/978-94-017-8742-0_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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12
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Braakman R, Smith E. Metabolic evolution of a deep-branching hyperthermophilic chemoautotrophic bacterium. PLoS One 2014; 9:e87950. [PMID: 24516572 PMCID: PMC3917532 DOI: 10.1371/journal.pone.0087950] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 01/05/2014] [Indexed: 11/19/2022] Open
Abstract
Aquifex aeolicus is a deep-branching hyperthermophilic chemoautotrophic bacterium restricted to hydrothermal vents and hot springs. These characteristics make it an excellent model system for studying the early evolution of metabolism. Here we present the whole-genome metabolic network of this organism and examine in detail the driving forces that have shaped it. We make extensive use of phylometabolic analysis, a method we recently introduced that generates trees of metabolic phenotypes by integrating phylogenetic and metabolic constraints. We reconstruct the evolution of a range of metabolic sub-systems, including the reductive citric acid (rTCA) cycle, as well as the biosynthesis and functional roles of several amino acids and cofactors. We show that A. aeolicus uses the reconstructed ancestral pathways within many of these sub-systems, and highlight how the evolutionary interconnections between sub-systems facilitated several key innovations. Our analyses further highlight three general classes of driving forces in metabolic evolution. One is the duplication and divergence of genes for enzymes as these progress from lower to higher substrate specificity, improving the kinetics of certain sub-systems. A second is the kinetic optimization of established pathways through fusion of enzymes, or their organization into larger complexes. The third is the minimization of the ATP unit cost to synthesize biomass, improving thermodynamic efficiency. Quantifying the distribution of these classes of innovations across metabolic sub-systems and across the tree of life will allow us to assess how a tradeoff between maximizing growth rate and growth efficiency has shaped the long-term metabolic evolution of the biosphere.
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Affiliation(s)
- Rogier Braakman
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, United States of America
- * E-mail:
| | - Eric Smith
- Santa Fe Institute, Santa Fe, New Mexico, United States of America
- Krasnow Institute for Advanced Study, George Mason University, Fairfax, Virginia, United States of America
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13
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ten Brink F, Schoepp-Cothenet B, van Lis R, Nitschke W, Baymann F. Multiple Rieske/cytb complexes in a single organism. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1827:1392-406. [PMID: 23507620 DOI: 10.1016/j.bbabio.2013.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 03/01/2013] [Accepted: 03/06/2013] [Indexed: 11/28/2022]
Abstract
Most organisms contain a single Rieske/cytb complex. This enzyme can be integrated in any respiratory or photosynthetic electron transfer chain that is quinone-based and sufficiently energy rich to allow for the turnover of three enzymes - a quinol reductase, a Rieske/cytb complex and a terminal oxidase. Despite this universal usability of the enzyme a variety of phylogenetically distant organisms have multiple copies thereof and no reason for this redundancy is obvious. In this review we present an overview of the distribution of multiple copies among species and describe their properties from the scarce experimental results, analysis of their amino acid sequences and genomic context. We discuss the predicted redox properties of the Rieske cluster in relation to the nature of the pool quinone. It appears that acidophilic iron-oxidizing bacteria specialized one of their two copies for reverse electron transfer, archaeal Thermoprotei adapted their three copies to the interaction with different oxidases and several, phylogenetically unrelated species imported a second complex with a putative heme ci that may confer some yet to be determined properties to the complex. These hypothesis and all the more the so far completely unexplained cases call for further studies and we put forward a number of suggestions for future research that we hope to be stimulating for the field. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes.
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Affiliation(s)
- F ten Brink
- BIP/UMR7281, FR3479, CNRS/AMU, 13 chemin Joseph Aiguier, 13009 Marseille, France
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14
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Guiral M, Prunetti L, Aussignargues C, Ciaccafava A, Infossi P, Ilbert M, Lojou E, Giudici-Orticoni MT. The hyperthermophilic bacterium Aquifex aeolicus: from respiratory pathways to extremely resistant enzymes and biotechnological applications. Adv Microb Physiol 2013; 61:125-94. [PMID: 23046953 DOI: 10.1016/b978-0-12-394423-8.00004-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aquifex aeolicus isolated from a shallow submarine hydrothermal system belongs to the order Aquificales which constitute an important component of the microbial communities at elevated temperatures. This hyperthermophilic chemolithoautotrophic bacterium, which utilizes molecular hydrogen, molecular oxygen, and inorganic sulfur compounds to flourish, uses the reductive TCA cycle for CO(2) fixation. In this review, the intricate energy metabolism of A. aeolicus is described. As the chemistry of sulfur is complex and multiple sulfur species can be generated, A. aeolicus possesses a multitude of different enzymes related to the energy sulfur metabolism. It contains also membrane-embedded [NiFe] hydrogenases as well as oxidases enzymes involved in hydrogen and oxygen utilization. We have focused on some of these proteins that have been extensively studied and characterized as super-resistant enzymes with outstanding properties. We discuss the potential use of hydrogenases in an attractive H(2)/O(2) biofuel cell in replacement of chemical catalysts. Using complete genomic sequence and biochemical data, we present here a global view of the energy-generating mechanisms of A. aeolicus including sulfur compounds reduction and oxidation pathways as well as hydrogen and oxygen utilization.
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Affiliation(s)
- Marianne Guiral
- Unité de Bioénergétique et Ingénierie des Protéines, UMR7281-FR3479, CNRS, Aix-Marseille Université, Marseille, France.
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15
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16
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Baymann F, Schoepp-Cothenet B, Lebrun E, van Lis R, Nitschke W. Phylogeny of Rieske/cytb complexes with a special focus on the Haloarchaeal enzymes. Genome Biol Evol 2012; 4:720-9. [PMID: 22798450 PMCID: PMC3509893 DOI: 10.1093/gbe/evs056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Rieske/cytochrome b (Rieske/cytb) complexes are proton pumping quinol oxidases that are present in most bacteria and Archaea. The phylogeny of their subunits follows closely the 16S-rRNA phylogeny, indicating that chemiosmotic coupling was already present in the last universal common ancestor of Archaea and bacteria. Haloarchaea are the only organisms found so far that acquired Rieske/cytb complexes via interdomain lateral gene transfer. They encode two Rieske/cytb complexes in their genomes; one of them is found in genetic context with nitrate reductase genes and has its closest relatives among Actinobacteria and the Thermus/Deinococcus group. It is likely to function in nitrate respiration. The second Rieske/cytb complex of Haloarchaea features a split cytochrome b sequence as do Cyanobacteria, chloroplasts, Heliobacteria, and Bacilli. It seems that Haloarchaea acquired this complex from an ancestor of the above-mentioned phyla. Its involvement in the bioenergetic reaction chains of Haloarchaea is unknown. We present arguments in favor of the hypothesis that the ancestor of Haloarchaea, which relied on a highly specialized bioenergetic metabolism, that is, methanogenesis, and was devoid of quinones and most enzymes of anaerobic or aerobic bioenergetic reaction chains, integrated laterally transferred genes into its genome to respond to a change in environmental conditions that made methanogenesis unfavorable.
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17
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Heme-copper terminal oxidase using both cytochrome c and ubiquinol as electron donors. Proc Natl Acad Sci U S A 2012; 109:3275-80. [PMID: 22334648 DOI: 10.1073/pnas.1121040109] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The cytochrome c oxidase Cox2 has been purified from native membranes of the hyperthermophilic eubacterium Aquifex aeolicus. It is a cytochrome ba(3) oxidase belonging to the family B of the heme-copper containing terminal oxidases. It consists of three subunits, subunit I (CoxA2, 63.9 kDa), subunit II (CoxB2, 16.8 kDa), and an additional subunit IIa of 5.2 kDa. Surprisingly it is able to oxidize both reduced cytochrome c and ubiquinol in a cyanide sensitive manner. Cox2 is part of a respiratory chain supercomplex. This supercomplex contains the fully assembled cytochrome bc(1) complex and Cox2. Although direct ubiquinol oxidation by Cox2 conserves less energy than ubiquinol oxidation by the cytochrome bc(1) complex followed by cytochrome c oxidation by a cytochrome c oxidase, ubiquinol oxidation by Cox2 is of advantage when all ubiquinone would be completely reduced to ubiquinol, e.g., by the sulfidequinone oxidoreductase, because the cytochrome bc(1) complex requires the presence of ubiquinone to function according to the Q-cycle mechanism. In the case that all ubiquinone has been reduced to ubiquinol its reoxidation by Cox2 will enable the cytochrome bc(1) complex to resume working.
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18
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Kallas T. Cytochrome b 6 f Complex at the Heart of Energy Transduction and Redox Signaling. PHOTOSYNTHESIS 2012. [DOI: 10.1007/978-94-007-1579-0_21] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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19
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Prunetti L, Infossi P, Brugna M, Ebel C, Giudici-Orticoni MT, Guiral M. New functional sulfide oxidase-oxygen reductase supercomplex in the membrane of the hyperthermophilic bacterium Aquifex aeolicus. J Biol Chem 2010; 285:41815-26. [PMID: 20971847 DOI: 10.1074/jbc.m110.167841] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aquifex aeolicus, a hyperthermophilic and microaerophilic bacterium, obtains energy for growth from inorganic compounds alone. It was previously proposed that one of the respiratory pathways in this organism consists of the electron transfer from hydrogen sulfide (H(2)S) to molecular oxygen. H(2)S is oxidized by the sulfide quinone reductase, a membrane-bound flavoenzyme, which reduces the quinone pool. We have purified and characterized a novel membrane-bound multienzyme supercomplex that brings together all the molecular components involved in this bioenergetic chain. Our results indicate that this purified structure consists of one dimeric bc(1) complex (complex III), one cytochrome c oxidase (complex IV), and one or two sulfide quinone reductases as well as traces of the monoheme cytochrome c(555) and quinone molecules. In addition, this work strongly suggests that the cytochrome c oxidase in the supercomplex is a ba(3)-type enzyme. The supercomplex has a molecular mass of about 350 kDa and is enzymatically functional, reducing O(2) in the presence of the electron donor, H(2)S. This is the first demonstration of the existence of such a respirasome carrying a sulfide oxidase-oxygen reductase activity. Moreover, the kinetic properties of the sulfide quinone reductase change slightly when integrated in the supercomplex, compared with the free enzyme. We previously purified a complete respirasome involved in hydrogen oxidation and sulfur reduction from Aquifex aeolicus. Thus, two different bioenergetic pathways (sulfur reduction and sulfur oxidation) are organized in this bacterium as supramolecular structures in the membrane. A model for the energetic sulfur metabolism of Aquifex aeolicus is proposed.
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Affiliation(s)
- Laurence Prunetti
- Laboratoire de Bioénergétique et Ingénierie des Protéines, UPR 9036, IMM, IFR88-CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
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20
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Nitschke W, van Lis R, Schoepp-Cothenet B, Baymann F. The "green" phylogenetic clade of Rieske/cytb complexes. PHOTOSYNTHESIS RESEARCH 2010; 104:347-355. [PMID: 20130997 DOI: 10.1007/s11120-010-9532-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Accepted: 01/16/2010] [Indexed: 05/28/2023]
Abstract
More than a decade ago, Heliobacteria were recognised to contain a Rieske/cytb complex in which the cytochrome b subunit is split into two separate proteins, a peculiar feature characteristic of the cyanobacterial and plastidic b (6) f complex. The common presence of RCI-type reaction centres further emphasise possible evolutionary links between Heliobacteria, Chlorobiaceae and Cyanobacteria. In this contribution, we further explore the evolutionary relationships among these three phototrophic lineages by both molecular phylogeny and consideration of phylogenetic marker traits of the superfamily of Rieske/cytb complexes. The combination of these two methods suggests the existence of a "green" clade involving many non-phototrophs in addition to the mentioned RCI-type photosynthetic organisms. Structural and functional idiosyncrasies are (re-)interpreted in the framework of evolutionary biology and more specifically evolutionary bioenergetics.
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Affiliation(s)
- W Nitschke
- BIP, Centre National de la Recherche Scientifique, UPR9036, IFR88, 31 Chemin Joseph Aiguier, Marseille, France.
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21
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Duval S, Santini JM, Nitschke W, Hille R, Schoepp-Cothenet B. The small subunit AroB of arsenite oxidase: lessons on the [2Fe-2S] Rieske protein superfamily. J Biol Chem 2010; 285:20442-51. [PMID: 20421651 DOI: 10.1074/jbc.m110.113811] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Here, we describe the characterization of the [2Fe-2S] clusters of arsenite oxidases from Rhizobium sp. NT-26 and Ralstonia sp. 22. Both reduced Rieske proteins feature EPR signals similar to their homologs from Rieske-cyt b complexes, with g values at 2.027, 1.88, and 1.77. Redox titrations in a range of pH values showed that both [2Fe-2S] centers have constant E(m) values up to pH 8 at approximately +210 mV. Above this pH value, the E(m) values of both centers are pH-dependent, similar to what is observed for the Rieske-cyt b complexes. The redox properties of these two proteins, together with the low E(m) value (+160 mV) of the Alcaligenes faecalis arsenite oxidase Rieske (confirmed herein), are in line with the structural determinants observed in the primary sequences, which have previously been deduced from the study of Rieske-cyt b complexes. Since the published E(m) value of the Chloroflexus aurantiacus Rieske (+100 mV) is in conflict with this sequence analysis, we re-analyzed membrane samples of this organism and obtain a new value (+200 mV). Arsenite oxidase activity was affected by quinols and quinol analogs, which is similar to what is found with the Rieske-cyt b complexes. Together, these results show that the Rieske protein of arsenite oxidase shares numerous properties with its counterpart in the Rieske-cyt b complex. However, two cysteine residues, strictly conserved in the Rieske-cyt b-Rieske and considered to be crucial for its function, are not conserved in the arsenite oxidase counterpart. We discuss the role of these residues.
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Affiliation(s)
- Simon Duval
- Laboratoire de Bioénergétique et Ingénierie des Protéines UPR 9036, Institut de Biologie Structurale et Microbiologie, CNRS, F-13402 Marseille Cedex 20, France
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22
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Immobilization of the hyperthermophilic hydrogenase from Aquifex aeolicus bacterium onto gold and carbon nanotube electrodes for efficient H2 oxidation. J Biol Inorg Chem 2009; 14:1275-88. [DOI: 10.1007/s00775-009-0572-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Accepted: 07/04/2009] [Indexed: 10/20/2022]
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23
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Guiral M, Prunetti L, Lignon S, Lebrun R, Moinier D, Giudici-Orticoni MT. New Insights into the Respiratory Chains of the Chemolithoautotrophic and Hyperthermophilic Bacterium Aquifex aeolicus. J Proteome Res 2009; 8:1717-30. [DOI: 10.1021/pr8007946] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marianne Guiral
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Service de Microséquençage et de Spectrométrie de Masse, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France
| | - Laurence Prunetti
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Service de Microséquençage et de Spectrométrie de Masse, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France
| | - Sabrina Lignon
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Service de Microséquençage et de Spectrométrie de Masse, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France
| | - Régine Lebrun
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Service de Microséquençage et de Spectrométrie de Masse, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France
| | - Danielle Moinier
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Service de Microséquençage et de Spectrométrie de Masse, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France
| | - Marie-Thérèse Giudici-Orticoni
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France, and Service de Microséquençage et de Spectrométrie de Masse, IBSM-CNRS, 31 chemin Joseph Aiguier, 13402 Marseille cedex 20, France
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24
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A structural perspective on mechanism and function of the cytochrome bc (1) complex. Results Probl Cell Differ 2007; 45:253-78. [PMID: 18038116 DOI: 10.1007/400_2007_042] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The cytochrome bc (1) complex is a fundamental component of the energy conversion machinery of respiratory and photosynthetic electron transfer chains. The multi-subunit membrane protein complex couples electron transfer from hydroquinone to cytochrome c to the translocation of protons across the membrane, thereby substantially contributing to the proton motive force that is used for ATP synthesis. Considerable progress has been made with structural and functional studies towards complete elucidation of the Q cycle mechanism, which was originally proposed by Mitchell 30 years ago. Yet, open questions regarding key steps of the mechanism still remain. The role of the complex as a major source of reactive oxygen species and its implication in pathophysiological conditions has recently gained interest.
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25
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Yatsunyk LA, Dawson A, Carducci MD, Nichol GS, Walker FA. Models of the cytochromes: crystal structures and EPR spectral characterization of low-spin bis-imidazole complexes of (OETPP)Fe(III) having intermediate ligand plane dihedral angles. Inorg Chem 2007; 45:5417-28. [PMID: 16813405 DOI: 10.1021/ic060283h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The preparation, EPR spectra, and crystal structures of octaethyltetraphenylporphyrinatoiron(III) having two imidazole, N-benzylimidazole, and N-methylimidazole axial ligands are reported, [(OETPP)Fe(HIm)2]Cl, [(OETPP)Fe(N-BzIm)2]Cl, and [(OETPP)Fe(N-MeIm)2]Cl. Despite large variation in axial ligand size, the unit cell parameters for all complexes are very similar; each structure has the same basic motif, with large voids formed by the extended porphyrin framework (filled by ordered or disordered axial ligands and disordered solvent), which allows differently sized ligands to fit within the same cell dimensions. Each porphyrin core adopts a saddled conformation with absolute value(deltaC(beta)) = 1.13-1.15 A. The dihedral angles between axial ligand planes, delta phi, are far from being either ideal parallel or perpendicular: 30.1 degrees, 57.2 degrees for [(OETPP)Fe(HIm)2]Cl (molecules 1 and 2), 56.8 degrees for [(OETPP)Fe(N-BzIm)(2)]Cl, and 16.0 degrees, 44.6 degrees, 59.6 degrees, and 88.1 degrees for [(OETPP)Fe(N-MeIm)2]Cl, which has disordered axial ligands. Among the complexes of this study, an axial ligand delta phi of 56.8 degrees is found to be the largest "parallel" angle (as defined by the observation of a normal rhombic or Type II EPR signal (N-BzIm, g = 3.08, 2.19, 1.31)), while 57.2 degrees is found to be the smallest "perpendicular" delta phi (as defined by the observation of a "large gmax" or Type I EPR signal (HIm, gmax = 3.24)). From the results of this study, it is clear that the size of the largest g for Types I and II complexes varies continuously, with no break between the two. While the switch in EPR signal type, from Type II to Type I, appears to be very sharp in this study, this may be somewhat artificial based upon limited numbers of examples and the required saddle distortion of the (OETPP)Fe(III) complexes. However, in comparison to several proteins with dihedral angles near 60 degrees and Type II EPR spectra, we may conclude that the switch in EPR signal type occurs near 57 degrees +/- 3-5 degrees.
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Affiliation(s)
- Liliya A Yatsunyk
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721-0041, USA
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26
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Mooser D, Maneg O, MacMillan F, Malatesta F, Soulimane T, Ludwig B. The menaquinol-oxidizing cytochrome bc complex from Thermus thermophilus: Protein domains and subunits. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:1084-95. [PMID: 16908008 DOI: 10.1016/j.bbabio.2006.05.033] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Revised: 04/27/2006] [Accepted: 05/23/2006] [Indexed: 10/24/2022]
Abstract
A recently resolved respiratory complex III, isolated from the extreme thermophile Thermus thermophilus, is discussed in terms of cofactor and subunit composition, and with respect to the origin of its protein modules. The four polypeptides, encoded by a single operon, share general homologies to canonical complexes both of the bc and b6f type, but exhibit some unexpected features as well. Evidence for high thermostability of the isolated protein and for its quinol substrate specificity is derived from EPR and kinetic measurements. A functional integration of this complex into an aerobic electron transfer scheme, connecting known dehydrogenase activities to the terminal oxidase branches of Thermus is outlined, as well as the specific principles of redox protein interactions prevailing at high temperature. Findings from this enzyme are linked to present knowledge on other menaquinol oxidizing bc complexes.
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Affiliation(s)
- Daniela Mooser
- Molekulare Genetik, Institut für Biochemie, Biozentrum der J. W. Goethe-Universität, 60439 Frankfurt am Main, Germany.
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27
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Teschner T, Yatsunyk L, Schünemann V, Paulsen H, Winkler H, Hu C, Scheidt WR, Walker FA, Trautwein AX. Models of the membrane-bound cytochromes: mössbauer spectra of crystalline low-spin ferriheme complexes having axial ligand plane dihedral angles ranging from 0 degree to 90 degrees. J Am Chem Soc 2006; 128:1379-89. [PMID: 16433558 PMCID: PMC1525297 DOI: 10.1021/ja056343k] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Crystalline samples of four low-spin Fe(III) octaalkyltetraphenylporphyrinate and two low-spin Fe(III) tetramesitylporphyrinate complexes, all of which are models of the bis-histidine-coordinated cytochromes of mitochondrial complexes II, III, and IV and chloroplast complex b(6)f, and whose molecular structures and EPR spectra have been reported previously, have been investigated in detail by Mössbauer spectroscopy. The six complexes and the dihedral angles between axial ligand planes of each are [(TMP)Fe(1-MeIm)(2)]ClO(4) (0 degree), paral-[(OMTPP)Fe(1-MeIm)(2)]Cl (19.5 degrees), paral-[(TMP)Fe(5-MeHIm)(2)]ClO(4) (26 degrees, 30 degrees for two molecules in the unit cell whose EPR spectra overlap), [(OETPP)Fe(4-Me(2)NPy)(2)]Cl (70 degrees), perp-[(OETPP)Fe(1-MeIm)(2)]Cl (73 degrees), and perp-[(OMTPP)Fe(1-MeIm)(2)]Cl (90 degrees). Of these, the first three have been shown to exhibit normal rhombic EPR spectra, each with three clearly resolved g-values, while the last three have been shown to exhibit "large g(max)" EPR spectra at 4.2 K. It is found that the hyperfine coupling constants of the complexes are consistent with those reported previously for low-spin ferriheme systems, with the largest-magnitude hyperfine coupling constant, A(zz), being considerably smaller for the "parallel" complexes (400-540 kG) than for the strictly perpendicular complex (902 kG), A(xx) being negative for all six complexes, and A(zz) and A(xx) being of similar magnitude for the "parallel" complexes (for example, for [(TMP)Fe(1-MeIm)(2)]Cl, A(zz) = 400 kG, A(xx) = -400 kG). In all cases, A(yy) is small but difficult to estimate with accuracy. With results for six structurally characterized model systems, we find for the first time qualitative correlations of g(zz), A(zz), and DeltaE(Q) with axial ligand plane dihedral angle Deltavarphi.
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28
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Walker FA. The heme environment of mouse neuroglobin: histidine imidazole plane orientations obtained from solution NMR and EPR spectroscopy as compared with X-ray crystallography. J Biol Inorg Chem 2006; 11:391-7. [PMID: 16586113 DOI: 10.1007/s00775-006-0095-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2006] [Accepted: 02/22/2006] [Indexed: 12/16/2022]
Abstract
The 1H NMR chemical shifts of the heme methyl groups of the ferriheme complex of metneuroglobin (Du et al. in J. Am. Chem. Soc. 125:8080-8081, 2003) predict orientations of the axial histidine ligands (Shokhirev and Walker in J. Biol. Inorg. Chem. 3:581-594, 1998) that are not consistent with the X-ray data (Vallone et al. in Proteins Struct. Funct. Bioinf. 56:85-94, 2004), and the EPR spectrum (Vinck et al. in J. Am. Chem. Soc. 126:4516-4517, 2004) is only marginally consistent with these data. The reasons for these inconsistencies appear to be rooted in the high degree of aqueous solution exposure of the heme group and the fact that there are no strong hydrogen-bond acceptors for the histidine imidazole N-H protons provided by the protein. Similar inconsistencies may exist for other water-soluble heme proteins, and 1H NMR spectroscopy provides a simple means to verify whether the solution structure of the heme center is the same as or different from that in the crystalline state.
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Affiliation(s)
- F Ann Walker
- Department of Chemistry, The University of Arizona, PO Box 210041, Tucson, AZ 85721-0041, USA.
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29
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Cape JL, Bowman MK, Kramer DM. Understanding the cytochrome bc complexes by what they don't do. The Q-cycle at 30. TRENDS IN PLANT SCIENCE 2006; 11:46-55. [PMID: 16352458 DOI: 10.1016/j.tplants.2005.11.007] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 10/20/2005] [Accepted: 11/25/2005] [Indexed: 05/05/2023]
Abstract
The cytochrome (cyt) bc(1), b(6)f and related complexes are central components of the respiratory and photosynthetic electron transport chains. These complexes carry out an extraordinary sequence of electron and proton transfer reactions that conserve redox energy in the form of a trans-membrane proton motive force for use in synthesizing ATP and other processes. Thirty years ago, Peter Mitchell proposed a general turnover mechanism for these complexes, which he called the Q-cycle. Since that time, many opposing schemes have challenged the Q-cycle but, with the accumulation of large amounts of biochemical, kinetic, thermodynamic and high-resolution structural data, the Q-cycle has triumphed as the accepted model, although some of the intermediate steps are poorly understood and still controversial. One of the major research questions concerning the cyt bc(1) and b(6)f complexes is how these enzymes suppress deleterious and dissipative side reactions. In particular, most Q-cycle models involve reactive semiquinone radical intermediates that can reduce O(2) to superoxide and lead to cellular oxidative stress. Current models to explain the avoidance of side reactions involve unprecedented or unusual enzyme mechanisms, the testing of which will involve new theoretical and experimental approaches.
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Affiliation(s)
- Jonathan L Cape
- Institute of Biological Chemistry, Washington State University, 289 Clark Hall, Pullman, WA 99164-6314, USA
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30
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Guiral M, Tron P, Aubert C, Gloter A, Iobbi-Nivol C, Giudici-Orticoni MT. A Membrane-bound Multienzyme, Hydrogen-oxidizing, and Sulfur-reducing Complex from the Hyperthermophilic Bacterium Aquifex aeolicus. J Biol Chem 2005; 280:42004-15. [PMID: 16236714 DOI: 10.1074/jbc.m508034200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aquifex aeolicus is a hyperthermophilic, chemolithoautotrophic, hydrogen-oxidizing, and microaerophilic bacterium growing at 85 degrees C. We have shown that it can grow on an H2/S degrees medium and produce H2S from sulfur in the later exponential phase. The complex carrying the sulfur reducing activity (electron transport from H2 to S degrees ) has been purified and characterized. It is a membrane-bound multiprotein complex containing a [NiFe] hydrogenase and a sulfur reductase connected via quinones. The sulfur reductase is encoded by an operon annotated dms (dimethyl sulfoxide reductase) that we have renamed sre and is composed of three subunits. Sequence analysis showed that it belongs to the Me2SO reductase molybdoenzyme family and is similar to the sulfur/polysulfide/thiosulfate/tetrathionate reductases. The study of catalytic properties clearly demonstrated that it can reduce tetrathionate, sulfur, and polysulfide, but cannot reduce Me2SO and thiosulfate, and that NADPH increases the sulfur reducing activity. To date, this is the first characterization of a supercomplex from a bacterium that couples hydrogen oxidation and sulfur reduction. The distinctive feature in A. aeolicus is the cytoplasmic localization of the sulfur reduction, which is in accordance with the presence of sulfur globules in the cytoplasm. Association of this sulfur-reducing complex with a hydrogen-oxygen pathway complex (hydrogenase I, bc1 complex) in the membrane suggests that subcomplexes involved in respiratory chains in this bacterium are part of supramolecular organization.
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Affiliation(s)
- Marianne Guiral
- Laboratoire de Bioénergétique et Ingénierie des Protéines, IBSM-CNRS, 13402 Marseille, France
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31
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Affiliation(s)
- Ivano Bertini
- Magnetic Resonance Center (CERM), University of Florence, Via L. Sacconi 6, 50019 Sesto Fiorentino, Italy.
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32
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Schneider D, Schmidt CL. Multiple Rieske proteins in prokaryotes: where and why? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2005; 1710:1-12. [PMID: 16271700 DOI: 10.1016/j.bbabio.2005.09.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 09/19/2005] [Accepted: 09/20/2005] [Indexed: 11/28/2022]
Abstract
Many microbial genomes have been sequenced in the recent years. Multiple genes encoding Rieske iron-sulfur proteins, which are subunits of cytochrome bc-type complexes or oxygenases, have been detected in many pro- and eukaryotic genomes. The diversity of substrates, co-substrates and reactions offers obvious explanations for the diversity of the low potential Rieske proteins associated with oxygenases, but the physiological significance of the multiple genes encoding high potential Rieske proteins associated with the cytochrome bc-type complexes remains elusive. For some organisms, investigations into the function of the later group of genes have been initiated. Here, we summarize recent finding on the characteristics and physiological functions of multiple high potential Rieske proteins in prokaryotes. We suggest that the existence of multiple high potential Rieske proteins in prokaryotes could be one way of allowing an organism to adapt their electron transfer chains to changing environmental conditions.
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Affiliation(s)
- Dirk Schneider
- Albert-Ludwigs-University Freiburg, Institut für Biochemie und Molekularbiologie, Stefan-Meier-Strasse 19, 79104 Freiburg, Germany.
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33
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Pollack JD, Li Q, Pearl DK. Taxonomic utility of a phylogenetic analysis of phosphoglycerate kinase proteins of Archaea, Bacteria, and Eukaryota: Insights by Bayesian analyses. Mol Phylogenet Evol 2005; 35:420-30. [PMID: 15804412 DOI: 10.1016/j.ympev.2005.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Revised: 02/04/2005] [Accepted: 02/07/2005] [Indexed: 10/25/2022]
Abstract
We studied 131 protein sequences of the essentially ubiquitous glycolytic enzyme 3-phosphoglycerate kinase (3-PGK) by Bayesian analyses in three Domains: 15 Archaea, 83 Bacteria, and 33 Eukaryota. The posterior distribution of phylogenetic trees developed were based on a uniform prior, the WAG model of protein evolution, Metropolis-Hastings sampling in a Markov chain Monte Carlo analysis, and a package of diagnostics to critically evaluate the validity of the analyses. The 15 Archaea separated with high posterior probability. The archaean Phyla Euryarchaeota and the apparently Euryarchaeota derived Crenarchaeota were monophyletic. The 33 Eukaryota separated into two main groups: the non-chlorophyllous forms with coherent sub-groupings of Euglenozoa, Alveolata, Fungi, and Metazoa and all the chlorophyllous species studied: the Plantae (Viridaeplantae), chlorophyllous Stramenopiles, and the chlorophyllous Bacteria. This association supports other opinions concerning the related lineage of cyanobacteria and the Plantae. The 3-PGK sequences from 83 Bacteria in almost every instance associated by their recognized taxal group: alpha-, beta-, gamma-, epsilon-proteobacteria, Chlamydia, Actinobacteridae, and Firmicutes. Firmicutes sequences were subdivided into three apparently monophyletic groups: the anaerobic Clostridia, the spore-forming Bacillales and a group containing the Mollicutes, Lactobacillales and non-spore-forming Bacillales. The 3-PGK-gene tree assemblage was notable both for its pervasive clustering in three Domains according to recognized taxonomic groupings of Class, Order, Family, and Genus. The 3-PGK enzyme or 3-PGK-like activity may have played a central role in the metabolism of the Universal Ancestor.
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Affiliation(s)
- J Dennis Pollack
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University, 333 West 10th Avenue, Columbus, OH 43210, USA.
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Baymann F, Lebrun E, Nitschke W. Mitochondrial cytochrome c1 is a collapsed di-heme cytochrome. Proc Natl Acad Sci U S A 2004; 101:17737-40. [PMID: 15591339 PMCID: PMC539742 DOI: 10.1073/pnas.0407442101] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2004] [Indexed: 11/18/2022] Open
Abstract
Cytochrome c(1) from mitochondrial complex III and the di-heme cytochromes c in the corresponding enzyme from epsilon-proteobacteria have so far been considered to represent unrelated cytochromes. A missing link protein discovered in the genome of the hyperthermophilic bacterium Aquifex aeolicus, however, provides evidence for a close evolutionary relationship between these two cytochromes. The mono-heme cytochrome c(1) from A. aeolicus contains stretches of strong sequence homology toward the epsilon-proteobacterial di-heme cytochromes. These di-heme cytochromes are shown to belong to the cytochrome c(4) family. Mapping cytochrome c(1) onto the di-heme sequences and structures demonstrates that cytochrome c(1) results from a mutation-induced collapse of the di-heme cytochrome structure and provides an explanation for its uncommon structural features. The appearance of cytochrome c(1) thus represents an extension of the biological protein repertoire quite different from the widespread innovation by gene duplication and subsequent diversification.
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Affiliation(s)
- Frauke Baymann
- Bioénergétique et Ingénierie des Protéines/Institut de Biologie Structurale et Microbiologie, Centre National de la Recherche Scientifique, Marseille, 31, Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
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Walker FA. Models of the Bis-Histidine-Ligated Electron-Transferring Cytochromes. Comparative Geometric and Electronic Structure of Low-Spin Ferro- and Ferrihemes. Chem Rev 2004; 104:589-615. [PMID: 14871136 DOI: 10.1021/cr020634j] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- F Ann Walker
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721-0041, USA.
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