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Milrad Y, Mosebach L, Buchert F. Regulation of Microalgal Photosynthetic Electron Transfer. PLANTS (BASEL, SWITZERLAND) 2024; 13:2103. [PMID: 39124221 PMCID: PMC11314055 DOI: 10.3390/plants13152103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 07/24/2024] [Accepted: 07/26/2024] [Indexed: 08/12/2024]
Abstract
The global ecosystem relies on the metabolism of photosynthetic organisms, featuring the ability to harness light as an energy source. The most successful type of photosynthesis utilizes a virtually inexhaustible electron pool from water, but the driver of this oxidation, sunlight, varies on time and intensity scales of several orders of magnitude. Such rapid and steep changes in energy availability are potentially devastating for biological systems. To enable a safe and efficient light-harnessing process, photosynthetic organisms tune their light capturing, the redox connections between core complexes and auxiliary electron mediators, ion passages across the membrane, and functional coupling of energy transducing organelles. Here, microalgal species are the most diverse group, featuring both unique environmental adjustment strategies and ubiquitous protective mechanisms. In this review, we explore a selection of regulatory processes of the microalgal photosynthetic apparatus supporting smooth electron flow in variable environments.
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Affiliation(s)
- Yuval Milrad
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Laura Mosebach
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
| | - Felix Buchert
- Institute of Plant Biology and Biotechnology, University of Münster, Schlossplatz 8, 48143 Münster, Germany
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2
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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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3
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Watson C, Niks D, Hille R, Vieira M, Schoepp-Cothenet B, Marques AT, Romão MJ, Santos-Silva T, Santini JM. Electron transfer through arsenite oxidase: Insights into Rieske interaction with cytochrome c. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2017; 1858:865-872. [PMID: 28801050 PMCID: PMC5574378 DOI: 10.1016/j.bbabio.2017.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/05/2017] [Accepted: 08/05/2017] [Indexed: 11/25/2022]
Abstract
Arsenic is a widely distributed environmental toxin whose presence in drinking water poses a threat to >140 million people worldwide. The respiratory enzyme arsenite oxidase from various bacteria catalyses the oxidation of arsenite to arsenate and is being developed as a biosensor for arsenite. The arsenite oxidase from Rhizobium sp. str. NT-26 (a member of the Alphaproteobacteria) is a heterotetramer consisting of a large catalytic subunit (AioA), which contains a molybdenum centre and a 3Fe-4S cluster, and a small subunit (AioB) containing a Rieske 2Fe-2S cluster. Stopped-flow spectroscopy and isothermal titration calorimetry (ITC) have been used to better understand electron transfer through the redox-active centres of the enzyme, which is essential for biosensor development. Results show that oxidation of arsenite at the active site is extremely fast with a rate of >4000s-1 and reduction of the electron acceptor is rate-limiting. An AioB-F108A mutation results in increased activity with the artificial electron acceptor DCPIP and decreased activity with cytochrome c, which in the latter as demonstrated by ITC is not due to an effect on the protein-protein interaction but instead to an effect on electron transfer. These results provide further support that the AioB F108 is important in electron transfer between the Rieske subunit and cytochrome c and its absence in the arsenite oxidases from the Betaproteobacteria may explain the inability of these enzymes to use this electron acceptor.
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Affiliation(s)
- Cameron Watson
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, WC1E 6BT, United Kingdom
| | - Dimitri Niks
- Department of Biochemistry, University of California; Riverside, Riverside, CA 92521, USA
| | - Russ Hille
- Department of Biochemistry, University of California; Riverside, Riverside, CA 92521, USA
| | - Marta Vieira
- UCIBIO-Requimte, Department of Chemistry, Faculty of Sciences and Technology, Universidade Nova de Lisboa, Portugal
| | | | - Alexandra T Marques
- UCIBIO-Requimte, Department of Chemistry, Faculty of Sciences and Technology, Universidade Nova de Lisboa, Portugal
| | - Maria João Romão
- UCIBIO-Requimte, Department of Chemistry, Faculty of Sciences and Technology, Universidade Nova de Lisboa, Portugal
| | - Teresa Santos-Silva
- UCIBIO-Requimte, Department of Chemistry, Faculty of Sciences and Technology, Universidade Nova de Lisboa, Portugal
| | - Joanne M Santini
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, WC1E 6BT, United Kingdom.
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4
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Adamson H, Robinson M, Bond PS, Soboh B, Gillow K, Simonov AN, Elton DM, Bond AM, Sawers RG, Gavaghan DJ, Parkin A. Analysis of HypD Disulfide Redox Chemistry via Optimization of Fourier Transformed ac Voltammetric Data. Anal Chem 2017; 89:1565-1573. [PMID: 28029041 DOI: 10.1021/acs.analchem.6b03589] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Rapid disulfide bond formation and cleavage is an essential mechanism of life. Using large amplitude Fourier transformed alternating current voltammetry (FTacV) we have measured previously uncharacterized disulfide bond redox chemistry in Escherichia coli HypD. This protein is representative of a class of assembly proteins that play an essential role in the biosynthesis of the active site of [NiFe]-hydrogenases, a family of H2-activating enzymes. Compared to conventional electrochemical methods, the advantages of the FTacV technique are the high resolution of the faradaic signal in the higher order harmonics and the fact that a single electrochemical experiment contains all the data needed to estimate the (very fast) electron transfer rates (both rate constants ≥ 4000 s-1) and quantify the energetics of the cysteine disulfide redox-reaction (reversible potentials for both processes approximately -0.21 ± 0.01 V vs SHE at pH 6). Previously, deriving such data depended on an inefficient manual trial-and-error approach to simulation. As a highly advantageous alternative, we describe herein an automated multiparameter data optimization analysis strategy where the simulated and experimental faradaic current data are compared for both the real and imaginary components in each of the 4th to 12th harmonics after quantifying the charging current data using the time-domain response.
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Affiliation(s)
- Hope Adamson
- Department of Chemistry, University of York , Heslington, York, YO10 5DD, United Kingdom
| | - Martin Robinson
- Department of Computer Science, University of Oxford , Wolfson Building, Parks Road, Oxford, OX1 3QD, United Kingdom
| | - Paul S Bond
- Department of Chemistry, University of York , Heslington, York, YO10 5DD, United Kingdom
| | - Basem Soboh
- Experimental Molecular Biophysics, Freie Universität Berlin , Arnimalle 14, 14195 Berlin, Germany
| | - Kathryn Gillow
- Mathematical Institute, Andrew Wiles Building, University of Oxford , Radcliffe Observatory Quarter, Woodstock Road, Oxford, OX2 6GG, United Kingdom
| | - Alexandr N Simonov
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University , Clayton, Victoria 3800, Australia
| | - Darrell M Elton
- School of Engineering and Mathematical Sciences, La Trobe University , Bundoora, Victoria 3086, Australia
| | - Alan M Bond
- School of Chemistry and the ARC Centre of Excellence for Electromaterials Science, Monash University , Clayton, Victoria 3800, Australia
| | - R Gary Sawers
- Institute for Biology/Microbiology, Martin Luther University Halle-Wittenberg , Halle (Saale), Germany
| | - David J Gavaghan
- Department of Computer Science, University of Oxford , Wolfson Building, Parks Road, Oxford, OX1 3QD, United Kingdom
| | - Alison Parkin
- Department of Chemistry, University of York , Heslington, York, YO10 5DD, United Kingdom
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5
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Holt PJ, Efremov RG, Nakamaru-Ogiso E, Sazanov LA. Reversible FMN dissociation from Escherichia coli respiratory complex I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1777-1785. [PMID: 27555334 DOI: 10.1016/j.bbabio.2016.08.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 08/04/2016] [Accepted: 08/17/2016] [Indexed: 12/13/2022]
Abstract
Respiratory complex I transfers electrons from NADH to quinone, utilizing the reaction energy to translocate protons across the membrane. It is a key enzyme of the respiratory chain of many prokaryotic and most eukaryotic organisms. The reversible NADH oxidation reaction is facilitated in complex I by non-covalently bound flavin mononucleotide (FMN). Here we report that the catalytic activity of E. coli complex I with artificial electron acceptors potassium ferricyanide (FeCy) and hexaamineruthenium (HAR) is significantly inhibited in the enzyme pre-reduced by NADH. Further, we demonstrate that the inhibition is caused by reversible dissociation of FMN. The binding constant (Kd) for FMN increases from the femto- or picomolar range in oxidized complex I to the nanomolar range in the NADH reduced enzyme, with an FMN dissociation time constant of ~5s. The oxidation state of complex I, rather than that of FMN, proved critical to the dissociation. Such dissociation is not observed with the T. thermophilus enzyme and our analysis suggests that the difference may be due to the unusually high redox potential of Fe-S cluster N1a in E. coli. It is possible that the enzyme attenuates ROS production in vivo by releasing FMN under highly reducing conditions.
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Affiliation(s)
- Peter J Holt
- MRC Mitochondrial Biology Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Rouslan G Efremov
- Structural Biology Research Center, VIB, 1050 Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel (VUB), 1050 Brussels, Belgium
| | - Eiko Nakamaru-Ogiso
- Johnson Research Foundation, Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6059, United States
| | - Leonid A Sazanov
- Institute of Science and Technology Austria, Am Campus 1, A-3400 Klosterneuburg, Austria.
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6
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The competition between chemistry and biology in assembling iron–sulfur derivatives. Molecular structures and electrochemistry. Part III. {[Fe2S2](Cys)3(X)} (X=Asp, Arg, His) and {[Fe2S2](Cys)2(His)2} proteins. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2015.07.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Karagas NE, Jones CN, Osborn DJ, Dzierlenga AL, Oyala P, Konkle ME, Whitney EM, David Britt R, Hunsicker-Wang LM. The reduction rates of DEPC-modified mutant Thermus thermophilus Rieske proteins differ when there is a negative charge proximal to the cluster. J Biol Inorg Chem 2014; 19:1121-35. [PMID: 24916128 DOI: 10.1007/s00775-014-1167-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 05/31/2014] [Indexed: 10/25/2022]
Abstract
Rieske and Rieske-type proteins are electron transport proteins involved in key biological processes such as respiration, photosynthesis, and detoxification. They have a [2Fe-2S] cluster ligated by two cysteines and two histidines. A series of mutations, L135E, L135R, L135A, and Y158F, of the Rieske protein from Thermus thermophilus has been produced which probe the effects of the neighboring residues, in the second sphere, on the dynamics of cluster reduction and the reactivity of the ligating histidines. These properties were probed using titrations and modifications with diethyl pyrocarbonate (DEPC) at various pH values monitored using UV-Visible and circular dichroism spectrophotometry. These results, along with results from EPR studies, provide information on ligating histidine modification and rate of reduction of each of the mutant proteins. L135R, L135A, and Y158F react with DEPC similarly to wild type, resulting in modified protein with a reduced [2Fe-2S] cluster in <90 min, whereas L135E requires >15 h under the same conditions. Thus, the negative charge slows down the rate of reduction and provides an explanation as to why negatively charged residues are rarely, if ever, found in the equivalent position of other Rieske and Rieske-type proteins.
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Affiliation(s)
- Nicholas E Karagas
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, TX, 78212, USA
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8
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Liu J, Chakraborty S, Hosseinzadeh P, Yu Y, Tian S, Petrik I, Bhagi A, Lu Y. Metalloproteins containing cytochrome, iron-sulfur, or copper redox centers. Chem Rev 2014; 114:4366-469. [PMID: 24758379 PMCID: PMC4002152 DOI: 10.1021/cr400479b] [Citation(s) in RCA: 560] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Indexed: 02/07/2023]
Affiliation(s)
- Jing Liu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Saumen Chakraborty
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Parisa Hosseinzadeh
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yang Yu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Shiliang Tian
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Igor Petrik
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Ambika Bhagi
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yi Lu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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9
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Sarewicz M, Dutka M, Pintscher S, Osyczka A. Triplet state of the semiquinone-Rieske cluster as an intermediate of electronic bifurcation catalyzed by cytochrome bc1. Biochemistry 2013; 52:6388-95. [PMID: 23941428 PMCID: PMC3889490 DOI: 10.1021/bi400624m] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Efficient energy conversion often requires stabilization of one-electron intermediates within catalytic sites of redox enzymes. While quinol oxidoreductases are known to stabilize semiquinones, one of the famous exceptions includes the quinol oxidation site of cytochrome bc1 (Qo), for which detection of any intermediate states is extremely difficult. Here we discover a semiquinone at the Qo site (SQo) that is coupled to the reduced Rieske cluster (FeS) via spin-spin exchange interaction. This interaction creates a new electron paramagnetic resonance (EPR) transitions with the most prominent g = 1.94 signal shifting to 1.96 with an increase in the EPR frequency from X- to Q-band. The estimated value of isotropic spin-spin exchange interaction (|J0| = 3500 MHz) indicates that at a lower magnetic field (typical of X-band) the SQo-FeS coupled centers can be described as a triplet state. Concomitantly with the appearance of the SQo-FeS triplet state, we detected a g = 2.0045 radical signal that corresponded to the population of unusually fast-relaxing SQo for which spin-spin exchange does not exist or is too small to be resolved. The g = 1.94 and g = 2.0045 signals reached up to 20% of cytochrome bc1 monomers under aerobic conditions, challenging the paradigm of the high reactivity of SQo toward molecular oxygen. Recognition of stable SQo reflected in g = 1.94 and g = 2.0045 signals offers a new perspective on understanding the mechanism of Qo site catalysis. The frequency-dependent EPR transitions of the SQo-FeS coupled system establish a new spectroscopic approach for the detection of SQo in mitochondria and other bioenergetic systems.
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Affiliation(s)
- Marcin Sarewicz
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University , Kraków, Poland
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10
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Bandeiras TM, Freitas MC, Petrasch D, Kletzin A, Frazão C. SAD phasing towards structure determination of a thermostable Rieske ferredoxin with a novel stabilizing disulfide bridge. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:555-8. [PMID: 23695576 PMCID: PMC3660900 DOI: 10.1107/s1744309113008385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 03/26/2013] [Indexed: 11/10/2022]
Abstract
Rieske proteins and Rieske ferredoxins are ubiquitous electron-transfer metalloproteins that are characterized by a [2Fe-2S] cluster coordinated by pairs of cysteine and histidine residues. The thermoacidophilic archaeon Acidianus ambivalens contains a Rieske ferredoxin termed RFd2, which has an hitherto unknown additional region of 40-44 residues at the C-terminus with a Cx3C motif that introduces a novel disulfide bond within the Rieske fold. RFd2 was crystallized with the aim of determining its three-dimensional structure in order to understand the contribution of this as yet unique disulfide bridge to the function and stability of RFd2. RFd2 crystals were successively improved, increasing their diffraction to 1.9 Å resolution. Molecular replacement did not solve the RFd2 structure, but a highly multiple in-house diffraction data set collected at the Cu Kα edge led to solution of the phase problem.
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Affiliation(s)
- Tiago M. Bandeiras
- IBET – Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901 Oeiras, Portugal
- ITQB–UNL, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da Republica, 2780-157 Oeiras, Portugal
| | - Micael C. Freitas
- IBET – Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2780-901 Oeiras, Portugal
- ITQB–UNL, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da Republica, 2780-157 Oeiras, Portugal
| | - Dennis Petrasch
- Microbiology – Sulfur Biochemistry and Microbial Bioenergetics, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Arnulf Kletzin
- Microbiology – Sulfur Biochemistry and Microbial Bioenergetics, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Carlos Frazão
- ITQB–UNL, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da Republica, 2780-157 Oeiras, Portugal
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11
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Heterologously expressed arsenite oxidase: A system to study biogenesis and structure/function relationships of the enzyme family. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1701-8. [DOI: 10.1016/j.bbabio.2012.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/31/2012] [Accepted: 06/01/2012] [Indexed: 11/19/2022]
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12
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Chang HY, Ahn Y, Pace LA, Lin MT, Lin YH, Gennis RB. The diheme cytochrome c(4) from Vibrio cholerae is a natural electron donor to the respiratory cbb(3) oxygen reductase. Biochemistry 2010; 49:7494-503. [PMID: 20715760 DOI: 10.1021/bi1004574] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The respiratory chain of Vibrio cholerae contains three bd-type quinol oxygen reductases as well as one cbb(3) oxygen reductase. The cbb(3) oxygen reductase has been previously isolated and characterized; however, the natural mobile electron donor(s) that shuttles electrons between the bc(1) complex and the cbb(3) oxygen reductase is not known. The most likely candidates are the diheme cytochrome c(4) and monoheme cytochrome c(5), which have been previously shown to be present in the periplasm of aerobically grown cultures of V. cholerae. Both cytochromes c(4) and c(5) from V. cholerae have been cloned and expressed heterologously in Escherichia coli. It is shown that reduced cytochrome c(4) is a substrate for the purified cbb(3) oxygen reductase and can support steady state oxygen reductase activity of at least 300 e(-1)/s. In contrast, reduced cytochrome c(5) is not a good substrate for the cbb(3) oxygen reductase. Surprisingly, the dependence of the oxygen reductase activity on the concentration of cytochrome c(4) does not exhibit saturation. Global spectroscopic analysis of the time course of the oxidation of cytochrome c(4) indicates that the apparent lack of saturation is due to the strong dependence of K(M) and V(max) on the concentration of oxidized cytochrome c(4). Whether this is an artifact of the in vitro assay or has physiological significance remains unknown. Cyclic voltammetry was used to determine that the midpoint potentials of the two hemes in cytochrome c(4) are 240 and 340 mV (vs standard hydrogen electrode), similar to the electrochemical properties of other c(4)-type cytochromes. Genomic analysis shows a strong correlation between the presence of a c(4)-type cytochrome and a cbb(3) oxygen reductase within the beta- and gamma-proteobacterial clades, suggesting that cytochrome c(4) is the likely natural electron donor to the cbb(3) oxygen reductases within these organisms. These would include the beta-proteobacteria Neisseria meningitidis and Neisseria gonnorhoeae, in which the cbb(3) oxygen reductases are the only terminal oxidases in their respiratory chains, and the gamma-proteobacterium Pseudomonas stutzeri.
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Affiliation(s)
- Hsin-Yang Chang
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801, USA
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13
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Konkle ME, Muellner SK, Schwander AL, Dicus MM, Pokhrel R, Britt RD, Taylor AB, Hunsicker-Wang LM. Effects of pH on the Rieske protein from Thermus thermophilus: a spectroscopic and structural analysis. Biochemistry 2009; 48:9848-57. [PMID: 19772300 DOI: 10.1021/bi901126u] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Rieske protein from Thermus thermophilus (TtRp) and a truncated version of the protein (truncTtRp), produced to achieve a low-pH crystallization condition, have been characterized using UV-visible and circular dichroism spectroscopies. TtRp and truncTtRp undergo a change in the UV-visible spectra with increasing pH. The LMCT band at 458 nm shifts to 436 nm and increases in intensity. The increase at 436 nm versus pH can be fit using the sum of two Henderson-Hasselbalch equations, yielding two pK(a) values for the oxidized protein. For TtRp, pK(ox1) = 7.48 +/- 0.12 and pK(ox2) = 10.07 +/- 0.17. For truncTtRp, pK(ox1) = 7.87 +/- 0.17 and pK(ox2) = 9.84 +/- 0.42. The shift to shorter wavelength and the increase in intensity for the LMCT band with increasing pH are consistent with deprotonation of the histidine ligands. A pH titration of truncTtRp monitored by circular dichroism also showed pH-dependent changes at 315 and 340 nm. At 340 nm, the fit gives pK(ox1) = 7.14 +/- 0.26 and pK(ox2) = 9.32 +/- 0.36. The change at 315 nm is best fit for a single deprotonation event, giving pK(ox1) = 7.82 +/- 0.10. The lower wavelength region of the CD spectra was unaffected by pH, indicating that the overall fold of the protein remains unchanged, which is consistent with crystallographic results of truncTtRp. The structure of truncTtRp crystallized at pH 6.2 is very similar to TtRp at pH 8.5 and contains only subtle changes localized at the [2Fe-2S] cluster. These titration and structural results further elucidate the histidine ligand characteristics and are consistent with important roles for these amino acids.
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Affiliation(s)
- Mary E Konkle
- Department of Chemistry, Trinity University, One Trinity Place, San Antonio, Texas 78212, USA
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14
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Sarewicz M, Dutka M, Froncisz W, Osyczka A. Magnetic interactions sense changes in distance between heme b(L) and the iron-sulfur cluster in cytochrome bc(1). Biochemistry 2009; 48:5708-20. [PMID: 19415898 PMCID: PMC2697599 DOI: 10.1021/bi900511b] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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During the operation of cytochrome bc1, a key enzyme of biological energy conversion, the iron−sulfur head domain of one of the subunits of the catalytic core undergoes a large-scale movement from the catalytic quinone oxidation Qo site to cytochrome c1. This changes a distance between the two iron−two sulfur (FeS) cluster and other cofactors of the redox chains. Although the role and the mechanism of this movement have been intensely studied, they both remain poorly understood, partly because the movement itself is not easily traceable experimentally. Here, we take advantage of magnetic interactions between the reduced FeS cluster and oxidized heme bL to use dipolar enhancement of phase relaxation of the FeS cluster as a spectroscopic parameter which with a unique clarity and specificity senses changes in the distance between those two cofactors. The dipolar relaxation curves measured by EPR at Q-band in a glass state of frozen solution (i.e., under the conditions trapping a dynamic distribution of FeS positions that existed in a liquid phase) of isolated cytochrome bc1 were compared with the curves calculated for the FeS cluster occupying distinct positions in various crystals of cytochrome bc1. This comparison revealed the existence of a broad distribution of the FeS positions in noninhibited cytochrome bc1 and demonstrated that the average equilibrium position is modifiable by inhibitors or mutations. To explain the results, we assume that changes in the equilibrium distribution of the FeS positions are the result of modifications of the orienting potential gradient in which the diffusion of the FeS head domain takes place. The measured changes in the phase relaxation enhancement provide the first direct experimental description of changes in the strength of dipolar coupling between the FeS cluster and heme bL.
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Affiliation(s)
- Marcin Sarewicz
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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Chobot SE, Hernandez HH, Drennan CL, Elliott SJ. Direct electrochemical characterization of archaeal thioredoxins. Angew Chem Int Ed Engl 2007; 46:4145-7. [PMID: 17443752 DOI: 10.1002/anie.200604620] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sarah E Chobot
- Department of Chemistry, Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
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Chobot S, Hernandez H, Drennan C, Elliott S. Direct Electrochemical Characterization of Archaeal Thioredoxins. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200604620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Kolling DJ, Brunzelle JS, Lhee S, Crofts AR, Nair SK. Atomic resolution structures of rieske iron-sulfur protein: role of hydrogen bonds in tuning the redox potential of iron-sulfur clusters. Structure 2007; 15:29-38. [PMID: 17223530 PMCID: PMC1868424 DOI: 10.1016/j.str.2006.11.012] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 11/16/2006] [Accepted: 11/16/2006] [Indexed: 11/26/2022]
Abstract
The Rieske [2Fe-2S] iron-sulfur protein of cytochrome bc(1) functions as the initial electron acceptor in the rate-limiting step of the catalytic reaction. Prior studies have established roles for a number of conserved residues that hydrogen bond to ligands of the [2Fe-2S] cluster. We have constructed site-specific variants at two of these residues, measured their thermodynamic and functional properties, and determined atomic resolution X-ray crystal structures for the native protein at 1.2 A resolution and for five variants (Ser-154-->Ala, Ser-154-->Thr, Ser-154-->Cys, Tyr-156-->Phe, and Tyr-156-->Trp) to resolutions between 1.5 A and 1.1 A. These structures and complementary biophysical data provide a molecular framework for understanding the role hydrogen bonds to the cluster play in tuning thermodynamic properties, and hence the rate of this bioenergetic reaction. These studies provide a detailed structure-function dissection of the role of hydrogen bonds in tuning the redox potentials of [2Fe-2S] clusters.
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Affiliation(s)
- Derrick J. Kolling
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801 USA
| | - Joseph S. Brunzelle
- Life Sciences Collaborative Access Team, Argonne National Labs, Argonne, IL, USA
| | - SangMoon Lhee
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801 USA
| | - Antony R. Crofts
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801 USA
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801 USA
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801 USA
- Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801 USA
- *Correspondence concerning this manuscript should be sent to: Dr. Satish K. Nair, Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave, Urbana, IL 61801 USA, Telephone: (217) 333-2688; Facsimile: (217) 244-5858 Electronic Mail:
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Abstract
The mitochondrion houses a variety of redox pathways, utilized for protection from oxidative damage and assembly of the organelle. The glutathione/glutaredoxin and thioredoxin systems function in the mitochondrial matrix. The intermembrane space is protected from oxidative damage via superoxide dismutase and glutathione. Subunits in the cytochrome bc (1) complex utilize disulfide bonds for enzymatic activity, whereas cytochrome oxidase relies on disulfide linkages for copper acquisition. A redox pathway (Mia40p and Erv1p) mediates the import of intermembrane space proteins such as the small Tim proteins, Cox17p, and Cox19p, which have disulfide bonds. Many of the candidate proteins with disulfide bridges possess a twin CX3C motif or CX9C motif and utilize both metal binding and disulfide linkages for function. It may seem surprising that the intermembrane space has developed redox pathways, considering that the buffered environment should be reducing like the cytosol. However, the prokaryotic origin of the mitochondrion suggests that the intermembrane space may be akin to the oxidative environment of the bacterial periplasm. Although the players forming disulfide bonds are not conserved between mitochondria and prokaryotes, the mitochondrion may have maintained redox chemistry as an assembly mechanism in the intermembrane space for the import of proteins and metals and enzymatic activity.
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Affiliation(s)
- Carla M Koehler
- Department of Chemistry and Biochemistry, Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California 90095-1569, USA.
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Hirst J. Elucidating the mechanisms of coupled electron transfer and catalytic reactions by protein film voltammetry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:225-39. [PMID: 16730325 DOI: 10.1016/j.bbabio.2006.04.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Revised: 03/28/2006] [Accepted: 04/01/2006] [Indexed: 11/30/2022]
Abstract
Protein film voltammetry, the direct electrochemistry of redox enzymes and proteins, provides precise and comprehensive information on complicated reaction mechanisms. By controlling the driving force for a reaction (using the applied potential) and monitoring the reaction in real time (using the current), it allows thermodynamic and kinetic information to be determined simultaneously. Two challenges are inherent to protein film voltammetry: (i) to adsorb the protein or enzyme in a native and active configuration on the electrode surface, and (ii) to understand and interpret voltammetric results on both a qualitative and quantitative level, allowing mechanistic models to be proposed and rigorous experiments to test these models to be devised. This review focuses on the second of these two challenges. It describes how to use protein film voltammetry to derive mechanistic and biochemically relevant information about redox proteins and enzymes, and how to evaluate and interpret voltammetric results. Selected key studies are described in detail, to illustrate their underlying principles, strategies and physical interpretations.
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Affiliation(s)
- Judy Hirst
- Medical Research Council Dunn Human Nutrition Unit, Wellcome Trust/MRC Building, Hills Road, Cambridge, CB2 2XY, UK.
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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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Leggate EJ, Bill E, Essigke T, Ullmann GM, Hirst J. Formation and characterization of an all-ferrous Rieske cluster and stabilization of the [2Fe-2S]0 core by protonation. Proc Natl Acad Sci U S A 2004; 101:10913-8. [PMID: 15263097 PMCID: PMC503719 DOI: 10.1073/pnas.0402711101] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The all-ferrous Rieske cluster, [2Fe-2S](0), has been produced in solution and characterized by protein-film voltammetry and UV-visible, EPR, and Mössbauer spectroscopies. The [2Fe-2S](0) cluster, in the overexpressed soluble domain of the Rieske protein from the bovine cytochrome bc(1) complex, is formed at -0.73 V at pH 7. Therefore, at pH 7, the [2Fe-2S](1+/0) couple is 1.0 V below the [2Fe-2S](2+/1+) couple. The two cluster-bound ferrous irons are both high spin (S = 2), and they are coupled antiferromagnetically (-J > or = 30 cm(-1), H =-2JS1.S2) to give a diamagnetic (S = 0) ground state. The ability of the Rieske cluster to exist in three oxidation states (2+, 1+, and 0) without an accompanying coupled reaction, such as a conformational change or protonation, is highly unusual. However, uncoupled reduction to the [2Fe-2S](0) state occurs at pH > 9.8 only, and at high pH the intact cluster persists in solution for <1 min. At pH < 9.8, the all-ferrous cluster is stabilized significantly by protonation. A combination of experimental data and calculations based on density functional theory suggests strongly that the proton binds to one of the cluster mu(2)-sulfides, consistent with observations that reduced [3Fe-4S] clusters are protonated also. The implications for our understanding of coupled reactions at iron-sulfur clusters and of the factors that determine the relative stabilities of their different oxidation states are discussed.
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Affiliation(s)
- Ellen J Leggate
- Medical Research Council Dunn Human Nutrition Unit, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 2XY, United Kingdom
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