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The extrinsic proteins of Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1817:121-42. [PMID: 21801710 DOI: 10.1016/j.bbabio.2011.07.006] [Citation(s) in RCA: 190] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 07/11/2011] [Accepted: 07/12/2011] [Indexed: 02/08/2023]
Abstract
In this review we examine the structure and function of the extrinsic proteins of Photosystem II. These proteins include PsbO, present in all oxygenic organisms, the PsbP and PsbQ proteins, which are found in higher plants and eukaryotic algae, and the PsbU, PsbV, CyanoQ, and CyanoP proteins, which are found in the cyanobacteria. These proteins serve to optimize oxygen evolution at physiological calcium and chloride concentrations. They also shield the Mn(4)CaO(5) cluster from exogenous reductants. Numerous biochemical, genetic and structural studies have been used to probe the structure and function of these proteins within the photosystem. We will discuss the most recent proposed functional roles for these components, their structures (as deduced from biochemical and X-ray crystallographic studies) and the locations of their proposed binding domains within the Photosystem II complex. This article is part of a Special Issue entitled: Photosystem II.
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Dreaden TM, Chen J, Rexroth S, Barry BA. N-formylkynurenine as a marker of high light stress in photosynthesis. J Biol Chem 2011; 286:22632-41. [PMID: 21527632 PMCID: PMC3121407 DOI: 10.1074/jbc.m110.212928] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 04/28/2011] [Indexed: 11/06/2022] Open
Abstract
Photosystem II (PSII) is the membrane protein complex that catalyzes the photo-induced oxidation of water at a manganese-calcium active site. Light-dependent damage and repair occur in PSII under conditions of high light stress. The core reaction center complex is composed of the D1, D2, CP43, and CP47 intrinsic polypeptides. In this study, a new chromophore formed from the oxidative post-translational modification of tryptophan is identified in the CP43 subunit. Tandem mass spectrometry peptide sequencing is consistent with the oxidation of the CP43 tryptophan side chain, Trp-365, to produce N-formylkynurenine (NFK). Characterization with ultraviolet visible absorption and ultraviolet resonance Raman spectroscopy supports this assignment. An optical assay suggests that the yield of NFK increases 2-fold (2.2 ± 0.5) under high light illumination. A concomitant 2.4 ± 0.5-fold decrease is observed in the steady-state rate of oxygen evolution under the high light conditions. NFK is the product formed from reaction of tryptophan with singlet oxygen, which can be produced under high light stress in PSII. Reactive oxygen species reactions lead to oxidative damage of the reaction center, D1 protein turnover, and inhibition of electron transfer. Our results are consistent with a role for the CP43 NFK modification in photoinhibition.
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Affiliation(s)
- Tina M. Dreaden
- From the School of Chemistry and Biochemistry and the Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Jun Chen
- From the School of Chemistry and Biochemistry and the Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Sascha Rexroth
- From the School of Chemistry and Biochemistry and the Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Bridgette A. Barry
- From the School of Chemistry and Biochemistry and the Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332
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3
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Shimada Y, Suzuki H, Tsuchiya T, Mimuro M, Noguchi T. Structural Coupling of an Arginine Side Chain with the Oxygen-Evolving Mn4Ca Cluster in Photosystem II As Revealed by Isotope-Edited Fourier Transform Infrared Spectroscopy. J Am Chem Soc 2011; 133:3808-11. [DOI: 10.1021/ja200186h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuichiro Shimada
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroyuki Suzuki
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Tohru Tsuchiya
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Mamoru Mimuro
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Takumi Noguchi
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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Shimada Y, Suzuki H, Tsuchiya T, Tomo T, Noguchi T, Mimuro M. Effect of a Single-Amino Acid Substitution of the 43 kDa Chlorophyll Protein on the Oxygen-Evolving Reaction of the Cyanobacterium Synechocystis sp. PCC 6803: Analysis of the Glu354Gln Mutation. Biochemistry 2009; 48:6095-103. [DOI: 10.1021/bi900317a] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuichiro Shimada
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroyuki Suzuki
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Tohru Tsuchiya
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Tatsuya Tomo
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
| | - Takumi Noguchi
- Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan
| | - Mamoru Mimuro
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan
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Ho FM. Uncovering channels in photosystem II by computer modelling: current progress, future prospects, and lessons from analogous systems. PHOTOSYNTHESIS RESEARCH 2008; 98:503-522. [PMID: 18798008 DOI: 10.1007/s11120-008-9358-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Accepted: 08/18/2008] [Indexed: 05/26/2023]
Abstract
Even prior to the publication of the crystal structures for photosystem II (PSII), it had already been suggested that water, O(2) and H(+) channels exist in PSII to achieve directed transport of these molecules, and to avoid undesirable side reactions. Computational efforts to uncover these channels and investigate their properties are still at early stages, and have so far only been based on the static PSII structure. The rationale behind the proposals for such channels and the computer modelling studies thus far are reviewed here. The need to take the dynamic protein into account is then highlighted with reference to the specific issues and techniques applicable to the simulation of each of the three channels. In particular, lessons are drawn from simulation studies on other protein systems containing similar channels.
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Affiliation(s)
- Felix M Ho
- Department of Photochemistry and Molecular Science, The Angström Laboratory, Uppsala University, Uppsala, Sweden.
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6
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Sproviero EM, McEvoy JP, Gascón JA, Brudvig GW, Batista VS. Computational insights into the O2-evolving complex of photosystem II. PHOTOSYNTHESIS RESEARCH 2008; 97:91-114. [PMID: 18483777 PMCID: PMC2728911 DOI: 10.1007/s11120-008-9307-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2007] [Accepted: 04/10/2008] [Indexed: 05/04/2023]
Abstract
Mechanistic investigations of the water-splitting reaction of the oxygen-evolving complex (OEC) of photosystem II (PSII) are fundamentally informed by structural studies. Many physical techniques have provided important insights into the OEC structure and function, including X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) spectroscopy as well as mass spectrometry (MS), electron paramagnetic resonance (EPR) spectroscopy, and Fourier transform infrared spectroscopy applied in conjunction with mutagenesis studies. However, experimental studies have yet to yield consensus as to the exact configuration of the catalytic metal cluster and its ligation scheme. Computational modeling studies, including density functional (DFT) theory combined with quantum mechanics/molecular mechanics (QM/MM) hybrid methods for explicitly including the influence of the surrounding protein, have proposed chemically satisfactory models of the fully ligated OEC within PSII that are maximally consistent with experimental results. The inorganic core of these models is similar to the crystallographic model upon which they were based, but comprises important modifications due to structural refinement, hydration, and proteinaceous ligation which improve agreement with a wide range of experimental data. The computational models are useful for rationalizing spectroscopic and crystallographic results and for building a complete structure-based mechanism of water-splitting in PSII as described by the intermediate oxidation states of the OEC. This review summarizes these recent advances in QM/MM modeling of PSII within the context of recent experimental studies.
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7
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Sproviero EM, Gascón JA, McEvoy JP, Brudvig GW, Batista VS. Quantum Mechanics/Molecular Mechanics Study of the Catalytic Cycle of Water Splitting in Photosystem II. J Am Chem Soc 2008; 130:3428-42. [DOI: 10.1021/ja076130q] [Citation(s) in RCA: 311] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Eduardo M. Sproviero
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107
| | - José A. Gascón
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107
| | - James P. McEvoy
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107
| | - Gary W. Brudvig
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107
| | - Victor S. Batista
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107
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Computational studies of the O(2)-evolving complex of photosystem II and biomimetic oxomanganese complexes. Coord Chem Rev 2008; 252:395-415. [PMID: 19190716 DOI: 10.1016/j.ccr.2007.09.006] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In recent years, there has been considerable interest in studies of catalytic metal clusters in metalloproteins based on Density Functional Theory (DFT) quantum mechanics/molecular mechanics (QM/MM) hybrid methods. These methods explicitly include the perturbational influence of the surrounding protein environment on the structural/functional properties of the catalytic centers. In conjunction with recent breakthroughs in X-ray crystallography and advances in spectroscopic and biophysical studies, computational chemists are trying to understand the structural and mechanistic properties of the oxygen-evolving complex (OEC) embedded in photosystem II (PSII). Recent studies include the development of DFT-QM/MM computational models of the Mn(4)Ca cluster, responsible for photosynthetic water oxidation, and comparative quantum mechanical studies of biomimetic oxomanganese complexes. A number of computational models, varying in oxidation and protonation states and ligation of the catalytic center by amino acid residues, water, hydroxide and chloride have been characterized along the PSII catalytic cycle of water splitting. The resulting QM/MM models are consistent with available mechanistic data, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction data and extended X-ray absorption fine structure (EXAFS) measurements. Here, we review these computational efforts focused towards understanding the catalytic mechanism of water oxidation at the detailed molecular level.
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Affiliation(s)
- My Hang V Huynh
- DE-1: High Explosive Science and Technology Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Meyer TJ, Huynh MHV, Thorp HH. The Possible Role of Proton-Coupled Electron Transfer (PCET) in Water Oxidation by Photosystem II. Angew Chem Int Ed Engl 2007; 46:5284-304. [PMID: 17604381 DOI: 10.1002/anie.200600917] [Citation(s) in RCA: 410] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
All higher life forms use oxygen and respiration as their primary energy source. The oxygen comes from water by solar-energy conversion in photosynthetic membranes. In green plants, light absorption in photosystem II (PSII) drives electron-transfer activation of the oxygen-evolving complex (OEC). The mechanism of water oxidation by the OEC has long been a subject of great interest to biologists and chemists. With the availability of new molecular-level protein structures from X-ray crystallography and EXAFS, as well as the accumulated results from numerous experiments and theoretical studies, it is possible to suggest how water may be oxidized at the OEC. An integrated sequence of light-driven reactions that exploit coupled electron-proton transfer (EPT) could be the key to water oxidation. When these reactions are combined with long-range proton transfer (by sequential local proton transfers), it may be possible to view the OEC as an intricate structure that is "wired for protons".
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Affiliation(s)
- Thomas J Meyer
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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11
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Meyer T, Huynh M, Thorp H. Zur möglichen Rolle des protonengekoppelten Elektronentransfers (PCET) bei der Oxidation von Wasser durch das Photosystem II. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200600917] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Popelková H, Yocum CF. Current status of the role of Cl(-) ion in the oxygen-evolving complex. PHOTOSYNTHESIS RESEARCH 2007; 93:111-21. [PMID: 17200880 DOI: 10.1007/s11120-006-9121-5] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Accepted: 12/04/2006] [Indexed: 05/07/2023]
Abstract
This minireview summarizes the current state of knowledge concerning the role of Cl(-) in the oxygen-evolving complex (OEC) of photosystem II (PSII). The model that proposes that Cl(-) is a Mn ligand is discussed in light of more recent work. Studies of Cl(-) specificity, stoichiometry, kinetics, and retention by extrinsic polypeptides are discussed, as are the results that fail to detect Cl(-) ligation to Mn and results that show a lack of a requirement for Cl(-) in PSII-catalyzed H(2)O oxidation. Mutagenesis experiments in cyanobacteria and higher plants that produce evidence for a correlation between Cl(-) retention and stable interactions among intrinsic and extrinsic polypeptides are summarized, and spectroscopic data on the interaction between PSII and Cl(-) are discussed. Lastly, the question of the site of Cl(-) action in PSII is discussed in connection with the current crystal structures of the enzyme.
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Affiliation(s)
- Hana Popelková
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA
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Suorsa M, Aro EM. Expression, assembly and auxiliary functions of photosystem II oxygen-evolving proteins in higher plants. PHOTOSYNTHESIS RESEARCH 2007; 93:89-100. [PMID: 17380423 DOI: 10.1007/s11120-007-9154-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Accepted: 02/26/2007] [Indexed: 05/14/2023]
Abstract
The oxygen-evolving complex (OEC) of higher plant photosystem II (PSII) consists of an inorganic Mn(4)Ca cluster and three nuclear-encoded proteins, PsbO, PsbP and PsbQ. In this review, we focus on the assembly of these OEC proteins, and especially on the role of the small intrinsic PSII proteins and recently found "novel" PSII proteins in the assembly process. The numerous auxiliary functions suggested during the past few years for the OEC proteins will likewise be discussed. For example, besides being a manganese-stabilizing protein, PsbO has been found to bind calcium and GTP and possess a carbonic anhydrase activity. In addition, specific roles have been suggested for the two isoforms of the PsbO protein in Arabidopsis thaliana. PsbP and PsbQ seem to play an additional role in the formation of PSII supercomplexes and in grana stacking, besides their originally recognized role in providing a proper calcium and chloride ion concentration for water splitting.
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Affiliation(s)
- Marjaana Suorsa
- Department of Biology, Plant Physiology and Molecular Biology, University of Turku, 20014 Turku, Finland
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14
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Kern J, Biesiadka J, Loll B, Saenger W, Zouni A. Structure of the Mn4-Ca cluster as derived from X-ray diffraction. PHOTOSYNTHESIS RESEARCH 2007; 92:389-405. [PMID: 17492491 DOI: 10.1007/s11120-007-9173-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 04/10/2007] [Indexed: 05/15/2023]
Abstract
The catalytic centre for light-induced water oxidation in photosystem II (PSII) is a multinuclear metal cluster containing four manganese and one calcium cations. Knowing the structure of this biological catalyst is of utmost importance for unravelling the mechanism of water oxidation in photosynthesis. In this review we describe the current state of the X-ray structure determination at 3.0 A resolution of the water oxidation complex (WOC) of PSII. The arrangement of metal cations in the cluster, their coordination and protein surroundings are discussed with regard to spectroscopic and mutagenesis studies. Limitations of the presently available structural data are pointed out and possible perspectives for the future are outlined, including the combination of X-ray diffraction and X-ray spectroscopy on single crystals.
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Affiliation(s)
- Jan Kern
- Institut für Chemie, Max Volmer Laboratorium für Biophysikalische Chemie, Sekr. PC 14, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
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Affiliation(s)
- James P McEvoy
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, USA
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Abstract
Water oxidation at photosystem II Mn-cluster is mediated by the redox-active tyrosine Y(Z). We calculated the redox potential (E(m)) of Y(Z) and its symmetrical counterpart Y(D), by solving the linearized Poisson-Boltzmann equation. The calculated E(m)(Y( )/Y(-)) were +926 mV/+694 mV for Y(Z)/Y(D) with the Mn-cluster in S2 state. Together with the asymmetric position of the Mn-cluster relative to Y(Z/D), differences in H-bond network between Y(Z) (Y(Z)/D1-His(190)/D1-Asn(298)) and Y(D) (Y(D)/D2-His(189)/D2-Arg(294)/CP47-Glu(364)) are crucial for E(m)(Y(Z/D)). When D1-His(190) is protonated, corresponding to a thermally activated state, the calculated E(m)(Y(Z)) was +1216 mV, which is as high as the E(m) for P(D1/D2). We observed deprotonation at CP43-Arg(357) upon S-state transition, which may suggest its involvement in the proton exit pathway. E(m)(Y(D)) was affected by formation of P(D2)(+) (but not P(D1)(+)) and sensitive to the protonation state of D2-Arg(180). This points to an electrostatic link between Y(D) and P(D2).
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Affiliation(s)
- Hiroshi Ishikita
- Institute of Chemistry and Biochemistry, Free University of Berlin, Berlin, Germany
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Ananyev G, Nguyen T, Putnam-Evans C, Dismukes GC. Mutagenesis of CP43-arginine-357 to serine reveals new evidence for (bi)carbonate functioning in the water oxidizing complex of Photosystem II. Photochem Photobiol Sci 2005; 4:991-8. [PMID: 16307112 DOI: 10.1039/b507519j] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The chlorophyll-binding protein CP43 is an inner subunit of the Photosystem II (PSII) reaction center core complex of all oxygenic photoautotrophs. X-Ray structural evidence places the guanidinium cation of the conserved arginine 357 residue of CP43 within a few Angstroms to the Mn(4)Ca cluster of the water-oxidizing complex (WOC) and has been implicated as a possible carbonate binding site. To test the hypothesis, the serine mutant, CP43-R357S, from Synechocystis PCC 6803 was investigated by PSII variable fluorescence (F(v)/F(m)) and simultaneous flash O(2) yield measurements in cells and thylakoid membranes. The R357S mutant assembles PSII-WOC centers, but is unable to grow photoautotrophically. Reconstitution of O(2) evolution by photoactivation and the occurrence of period-four oscillations of F(v)/F(m) establishes that the R357S mutant contains an assembled Mn(4)Ca cluster, but turnover is impaired as seen by an 11-fold larger Kok double miss parameter and faster decay of upper S states. Using pulsed light to avoid photoinactivation, wild-type cells and thylakoid membranes exhibit a 2-4-fold loss in O(2) evolution rate upon partial bicarbonate depletion under multiple turnover conditions, while the R357S mutant is unaffected by bicarbonate. Arginine R357 appears to function in binding a (bi)carbonate ion essential to normal catalytic turnover of the WOC. The quantum yield of electron donation from the WOC into PSII increases with decreasing turnover rate in R357S mutant cells and involves an aborted two-flash pathway that is distinct from the classical four-flash pattern. We speculate that an altered photochemical mechanism for O(2) production occurs via formation of hydrogen peroxide, by analogy to other treatments that retard the kinetics of proton release into the lumen.
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Affiliation(s)
- Gennady Ananyev
- Princeton University, Department of Chemistry and Princeton Environmental Institute, Princeton, NJ 08544, USA.
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Eaton-Rye JJ. Requirements for different combinations of the extrinsic proteins in specific cyanobacterial photosystem II mutants. PHOTOSYNTHESIS RESEARCH 2005; 84:275-81. [PMID: 16049786 DOI: 10.1007/s11120-005-0748-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Accepted: 01/17/2005] [Indexed: 05/03/2023]
Abstract
The crystallographic data available for Photosystem II (PS II) in cyanobacteria has now provided complete structures for loop E from CP43 and CP47 as well as the extrinsic subunits PsbO, PsbU and PsbV. Protein interactions between these subunits are essential for stable water splitting and there is evidence that the binding of PsbU facilitates optimal energy transfer from the phycobilisome. Interactions between PsbO and CP47 may also play a role in dimer stabilization while loop E of CP43 contributes directly to the water-splitting reaction. Recent evidence also suggests that homologs of PsbP and PsbQ play key roles in cyanobacterial PS II, and under nutrient-deficient conditions PsbQ appears essential for photoautotrophic growth.
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Affiliation(s)
- Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand.
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Ishikita H, Knapp EW. Redox potential of cytochrome c550 in the cyanobacterium Thermosynechococcus elongates. FEBS Lett 2005; 579:3190-4. [PMID: 15919077 DOI: 10.1016/j.febslet.2005.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Accepted: 05/03/2005] [Indexed: 11/18/2022]
Abstract
Cytochrome c550 (cyt c550) from photosystem II (PSII) exists in the PSII-bound form but can be released from PSII by treatment with divalent cations or Tris, yielding the isolated form. We calculated heme redox potentials (Em) based on the crystal structures of cyt c550 by solving the Poisson-Boltzmann equation. In the isolated form, the calculated Em are -240 mV at pH 6.0 and -352 mV at pH 9.0. This pH-dependence is predominantly due to deprotonation of the heme-propionic group near Asn-49. In the PSII-bound form, the calculated E(m) was up-shifted by 160 mV versus the isolated form due to a conformational change of protein backbone, yielding Em=-84 mV.
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Affiliation(s)
- Hiroshi Ishikita
- Institute of Chemistry, Department of Biology, Chemistry, and Pharmacy, Free University of Berlin, Takustrasse 6, D-14195 Berlin, Germany
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Ferreira KN, Iverson TM, Maghlaoui K, Barber J, Iwata S. Architecture of the photosynthetic oxygen-evolving center. Science 2004; 303:1831-8. [PMID: 14764885 DOI: 10.1126/science.1093087] [Citation(s) in RCA: 2335] [Impact Index Per Article: 116.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Photosynthesis uses light energy to drive the oxidation of water at an oxygen-evolving catalytic site within photosystem II (PSII). We report the structure of PSII of the cyanobacterium Thermosynechococcus elongatus at 3.5 angstrom resolution. We have assigned most of the amino acid residues of this 650-kilodalton dimeric multisubunit complex and refined the structure to reveal its molecular architecture. Consequently, we are able to describe details of the binding sites for cofactors and propose a structure of the oxygen-evolving center (OEC). The data strongly suggest that the OEC contains a cubane-like Mn3CaO4 cluster linked to a fourth Mn by a mono-micro-oxo bridge. The details of the surrounding coordination sphere of the metal cluster and the implications for a possible oxygen-evolving mechanism are discussed.
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Affiliation(s)
- Kristina N Ferreira
- Department of Biological Sciences, Imperial College London, London, SW7 2AZ, UK
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DasguptaThese authors contributed e J, van Willigen RT, Dismukes GC. Consequences of structural and biophysical studies for the molecular mechanism of photosynthetic oxygen evolution: functional roles for calcium and bicarbonate. Phys Chem Chem Phys 2004. [DOI: 10.1039/b408270b] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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McEvoy JP, Brudvig GW. Structure-based mechanism of photosynthetic water oxidation. Phys Chem Chem Phys 2004. [DOI: 10.1039/b407500e] [Citation(s) in RCA: 174] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Bricker TM, Young A, Frankel LK, Putnam-Evans C. Introduction of the 305Arg-->305Ser mutation in the large extrinsic loop E of the CP43 protein of Synechocystis sp. PCC 6803 leads to the loss of cytochrome c(550) binding to Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1556:92-6. [PMID: 12460665 DOI: 10.1016/s0005-2728(02)00367-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
CP43, a component of Photosystem II (PSII) in higher plants, algae and cyanobacteria, is encoded by the psbC gene. Previous work demonstrated that alteration of an arginine residue occurring at position 305 to serine produced a strain (R305S) with altered PSII characteristics including lower oxygen-evolving activity, fewer assembled reaction centers, higher sensitivity to photoinactivation, etc. [Biochemistry 38 (1999) 1582]. Additionally, it was determined that the mutant exhibited an enhanced stability of its S2 state. Recently, we observed a significant chloride effect under chloride-limiting conditions. The mutant essentially lost the ability to grow photoautotrophically, assembled fewer fully functional PSII reaction centers and exhibited a very low rate of oxygen evolution. Thus, the observed phenotype of this mutation is very similar to that observed for the Delta(psb)V mutant, which lacks cytochrome c550 (Biochemistry 37 (1998) 1551). A His-tagged version of the R305S mutant was produced to facilitate the isolation of PSII particles. These particles were analyzed for the presence of cytochrome c550. Reduced minus oxidized difference spectroscopy and chemiluminescence examination of Western blots indicated that cytochrome c550 was absent in these PSII particles. Whole cell extracts from the R305S mutant, however, contained a similar amount of cytochrome c550 to that observed in the control strain. These results indicate that the mutation R305S in CP43 prevents the strong association of cytochrome c550 with the PSII core complex. We hypothesize that this residue is involved in the formation of the binding domain for the cytochrome.
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Affiliation(s)
- Terry M Bricker
- Biochemistry and Molecular Biology Section, Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
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Anderson LB, Maderia M, Ouellette AJA, Putnam-Evans C, Higgins L, Krick T, MacCoss MJ, Lim H, Yates JR, Barry BA. Posttranslational modifications in the CP43 subunit of photosystem II. Proc Natl Acad Sci U S A 2002; 99:14676-81. [PMID: 12417747 PMCID: PMC137478 DOI: 10.1073/pnas.232591599] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2002] [Accepted: 10/01/2002] [Indexed: 11/18/2022] Open
Abstract
Photosystem II (PSII) catalyzes the light-driven oxidation of water and the reduction of plastoquinone; the oxidation of water occurs at a cluster of four manganese. The PSII CP43 subunit functions in light harvesting, and mutations in the fifth luminal loop (E) of CP43 have established its importance in PSII structure and/or assembly [Kuhn, M. G. & Vermaas, V. F. J. (1993) Plant Mol. Biol. 23, 123-133]. The sequence A(350)PWLEPLR(357) in luminal loop E is conserved in CP43 genes from 50 organisms. To map important posttranslational modifications in this sequence, tandem mass spectrometry (MS/MS) was used. These data show that the indole side chain of Trp-352 is posttranslationally modified to give mass shifts of +4, +16, and +18 daltons. The masses of the modifications suggest that the tryptophan is modified to kynurenine (+4), a keto-/amino-/hydroxy- (+16) derivative, and a dihydro-hydroxy- (+18) derivative of the indole side chain. Peptide synthesis and MS/MS confirmed the kynurenine assignment. The +16 and +18 tryptophan modifications may be intermediates formed during the oxidative cleavage of the indole ring to give kynurenine. The site-directed mutations, W352C, W352L, and W352A, exhibit an increased rate of photoinhibition relative to wild type. We hypothesize that Trp-352 oxidative modifications are a byproduct of PSII water-splitting or electron transfer reactions and that these modifications target PSII for turnover. As a step toward understanding the tertiary structure of this CP43 peptide, structural modeling was performed by using molecular dynamics.
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Affiliation(s)
- Lorraine B Anderson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, St. Paul 55108, USA
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Charbonnier F, Gaspera BD, Armand AS, Van der Laarse WJ, Launay T, Becker C, Gallien CL, Chanoine C. Two myogenin-related genes are differentially expressed in Xenopus laevis myogenesis and differ in their ability to transactivate muscle structural genes. J Biol Chem 2002; 277:1139-47. [PMID: 11684685 DOI: 10.1074/jbc.m107018200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Among the myogenic regulatory factors, myogenin is a transcriptional activator situated at a crucial position for terminal differentiation in muscle development. It is unclear at present whether myogenin exhibits unique specificities to transactivate late muscular markers. During Xenopus development, the accumulation of myogenin mRNA is restricted to secondary myogenesis, at the onset of the appearance of adult isoforms of beta-tropomyosin and myosin heavy chain. To determine the role of myogenin in the isoform switch of these contractile proteins, we characterized and directly compared the functional properties of myogenin with other myogenic regulatory factors in Xenopus embryos. Two distinct cDNAs related to myogenin, XmyogU1 and XmyogU2, were differentially expressed during myogenesis and in adult tissues, in which they preferentially accumulated in oxidative myofibers. Animal cap assays in Xenopus embryos revealed that myogenin, but not the other myogenic regulatory factors, induced expression of embryonic/larval isoforms of the beta-tropomyosin and myosin heavy chain genes. Only XmyogU1 induced expression of the adult fast isoform of the myosin heavy chain gene. This is the first demonstration of a specific transactivation of one set of muscle structural genes by myogenin.
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Affiliation(s)
- Frederic Charbonnier
- Laboratoire de Biologie du Développement et de la Différenciation Musculaire (EA 2507), Centre Universitaire des Saints-Pères, Université René Descartes, F-75270 Paris Cedex 06, France.
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Debus RJ. Amino acid residues that modulate the properties of tyrosine Y(Z) and the manganese cluster in the water oxidizing complex of photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1503:164-86. [PMID: 11115632 DOI: 10.1016/s0005-2728(00)00221-8] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The catalytic site for photosynthetic water oxidation is embedded in a protein matrix consisting of nearly 30 different polypeptides. Residues from several of these polypeptides modulate the properties of the tetrameric Mn cluster and the redox-active tyrosine residue, Y(Z), that are located at the catalytic site. However, most or all of the residues that interact directly with Y(Z) and the Mn cluster appear to be contributed by the D1 polypeptide. This review summarizes our knowledge of the environments of Y(Z) and the Mn cluster as obtained from the introduction of site-directed, deletion, and other mutations into the photosystem II polypeptides of the cyanobacterium Synechocystis sp. PCC 6803 and the green alga Chlamydomonas reinhardtii.
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Affiliation(s)
- R J Debus
- Department of Biochemistry, University of California, Riverside, CA 92521-0129, USA.
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Barber J, Morris E, Büchel C. Revealing the structure of the photosystem II chlorophyll binding proteins, CP43 and CP47. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1459:239-47. [PMID: 11004436 DOI: 10.1016/s0005-2728(00)00158-4] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A review of the structural properties of the photosystem II chlorophyll binding proteins, CP47 and CP43, is given and a model of the transmembrane helical domains of CP47 has been constructed. The model is based on (i) the amino acid sequence of the spinach protein, (ii) an 8 A three-dimensional electron density map derived from electron crystallography and (iii) the structural homology which the membrane spanning region of CP47 shares with the six N-terminal transmembrane helices of the PsaA/PsaB proteins of photosystem I. Particular emphasis has been placed on the position of chlorophyll molecules assigned in the 8 A three-dimensional map of CP47 (K.-H. Rhee, E.P. Morris, J. Barber, W. Kühlbrandt, Nature 396 (1998) 283-286) relative to histidine residues located in the transmembrane regions of this protein which are likely to form axial ligands for chlorophyll binding. Of the 14 densities assigned to chlorophyll, the model predicted that five have their magnesium ions within 4 A of the imidazole nitrogens of histidine residues. For the remaining seven histidine residues the densities attributed to chlorophylls were within 4-8 A of the imidazole nitrogens and thus too far apart for direct ligation with the magnesium ion within the tetrapyrrole head group. Improved structural resolution and reconsiderations of the orientation of the porphyrin rings will allow further refinement of the model.
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Affiliation(s)
- J Barber
- Biochemistry Department, Wolfson Laboratories, Imperial College of Science, Technology and Medicine, SW7 2AY, London, UK.
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Büchel C, Barber J, Ananyev G, Eshaghi S, Watt R, Dismukes C. Photoassembly of the manganese cluster and oxygen evolution from monomeric and dimeric CP47 reaction center photosystem II complexes. Proc Natl Acad Sci U S A 1999; 96:14288-93. [PMID: 10588698 PMCID: PMC24429 DOI: 10.1073/pnas.96.25.14288] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Isolated subcomplexes of photosystem II from spinach (CP47RC), composed of D1, D2, cytochrome b(559), CP47, and a number of hydrophobic small subunits but devoid of CP43 and the extrinsic proteins of the oxygen-evolving complex, were shown to reconstitute the Mn(4)Ca(1)Cl(x) cluster of the water-splitting system and to evolve oxygen. The photoactivation process in CP47RC dimers proceeds by the same two-step mechanism as observed in PSII membranes and exhibits the same stoichiometry for Mn(2+), but with a 10-fold lower affinity for Ca(2+) and an increased susceptibility to photodamage. After the lower Ca(2+) affinity and the 10-fold smaller absorption cross-section for photons in CP47 dimers is taken into account, the intrinsic rate constant for the rate-limiting calcium-dependent dark step is indistinguishable for the two systems. The monomeric form of CP47RC also showed capacity to photoactivate and catalyze water oxidation, but with lower activity than the dimeric form and increased susceptibility to photodamage. After optimization of the various parameters affecting the photoactivation process in dimeric CP47RC subcores, 18% of the complexes were functionally reconstituted and the quantum efficiency for oxygen production by reactivated centers approached 96% of that observed for reconstituted photosystem II-enriched membranes.
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Affiliation(s)
- C Büchel
- Biochemistry Department, Imperial College of Science, Technology and Medicine, London SW7 2AY, United Kingdom
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