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Kamada S, Nakajima Y, Shen JR. Structural insights into the action mechanisms of artificial electron acceptors in photosystem II. J Biol Chem 2023:104839. [PMID: 37209822 PMCID: PMC10300377 DOI: 10.1016/j.jbc.2023.104839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 05/07/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023] Open
Abstract
Photosystem II (PSII) utilizes light energy to split water, and the electrons extracted from water are transferred to QB, a plastoquinone (PQ) molecule bound to the D1 subunit of PSII. Many artificial electron acceptors (AEAs) with similar molecular structures to PQ can accept electrons from PSII. However, the molecular mechanism by which AEAs act on PSII is unclear. Here, we solved the crystal structure of PSII treated with three different AEAs, 2,5-dibromo-1,4-benzoquinone, 2,6-dichloro-1,4-benzoquinone, and 2-phenyl-1,4-benzoquinone, at 1.95-2.10 Å resolution. Our results show that all AEAs substitute for QB and are bound to the QB-binding site (QB site) to receive electrons, but their binding strengths are different, resulting in differences in their efficiencies to accept electrons. The acceptor 2-phenyl-1,4-benzoquinone binds most weakly to the QB site, and showed the highest oxygen-evolving activity, implying a reverse relationship between the binding strength and oxygen-evolving activity. In addition, a novel quinone binding site, designated the QD site, was discovered, which is located in the vicinity of QB site and close to QC site, a binding site reported previously. This QD site is expected to play a role as a channel or a storage site for quinones to be transported to the QB site. These results provide the structural basis for elucidating the actions of AEAs and exchange mechanism of QB in PSII, and also provide information for the design of more efficient electron acceptors.
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Affiliation(s)
- Shinji Kamada
- Faculty of Science, Okayama University, Okayama 700-8503, Japan
| | - Yoshiki Nakajima
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8503, Japan.
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8503, Japan.
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2
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Xu B, Chen Y, Yao R, Chen C, Zhang C. Redox‐Induced Structural Change in Artificial Heterometallic‐Oxide Cluster Mimicking the Photosynthetic Oxygen‐Evolving Center. Chemistry 2022; 28:e202201456. [DOI: 10.1002/chem.202201456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Boran Xu
- Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences 100190 Beijing P. R. China
- University of Chinese Academy of Sciences 100049 Beijing P. R. China
| | - Yang Chen
- Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences 100190 Beijing P. R. China
- University of Chinese Academy of Sciences 100049 Beijing P. R. China
| | - Ruoqing Yao
- Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences 100190 Beijing P. R. China
- University of Chinese Academy of Sciences 100049 Beijing P. R. China
| | - Changhui Chen
- Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences 100190 Beijing P. R. China
- University of Chinese Academy of Sciences 100049 Beijing P. R. China
| | - Chunxi Zhang
- Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences 100190 Beijing P. R. China
- University of Chinese Academy of Sciences 100049 Beijing P. R. China
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3
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Nixon PJ, Telfer A. Remembering James Barber (1940-2020). PHOTOSYNTHESIS RESEARCH 2022; 153:1-20. [PMID: 35534741 PMCID: PMC9522743 DOI: 10.1007/s11120-022-00919-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 03/31/2022] [Indexed: 06/14/2023]
Abstract
James Barber, known to colleagues and friends as Jim, passed away in January 2020 after a long battle against cancer. During his long and distinguished career in photosynthesis research, Jim made many outstanding contributions with the pinnacle achieving his dream of determining the first detailed structure of the Mn cluster involved in photosynthetic water oxidation. Here, colleagues and friends remember Jim and reflect upon his scientific career and the impact he had on their lives and the scientific community.
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Affiliation(s)
- Peter J Nixon
- Sir Ernst Chain Building - Wolfson Laboratories, Department of Life Sciences, Imperial College London, S. Kensington Campus, London, SW7 2AZ, UK.
| | - Alison Telfer
- Sir Ernst Chain Building - Wolfson Laboratories, Department of Life Sciences, Imperial College London, S. Kensington Campus, London, SW7 2AZ, UK.
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4
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Macromolecular conformational changes in photosystem II: interaction between structure and function. Biophys Rev 2022; 14:871-886. [DOI: 10.1007/s12551-022-00979-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/02/2022] [Indexed: 01/08/2023] Open
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5
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Koua FHM. Structural Changes in the Acceptor Site of Photosystem II upon Ca 2+/Sr 2+ Exchange in the Mn 4CaO 5 Cluster Site and the Possible Long-Range Interactions. Biomolecules 2019; 9:E371. [PMID: 31416291 PMCID: PMC6722538 DOI: 10.3390/biom9080371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Accepted: 08/12/2019] [Indexed: 01/15/2023] Open
Abstract
The Mn4CaO5 cluster site in the oxygen-evolving complex (OEC) of photosystem II (PSII) undergoes structural perturbations, such as those induced by Ca2+/Sr2+ exchanges or Ca/Mn removal. These changes have been known to induce long-range positive shifts (between +30 and +150 mV) in the redox potential of the primary quinone electron acceptor plastoquinone A (QA), which is located 40 Å from the OEC. To further investigate these effects, we reanalyzed the crystal structure of Sr-PSII resolved at 2.1 Å and compared it with the native Ca-PSII resolved at 1.9 Å. Here, we focus on the acceptor site and report the possible long-range interactions between the donor, Mn4Ca(Sr)O5 cluster, and acceptor sites.
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Affiliation(s)
- Faisal Hammad Mekky Koua
- Center for Free Electron Laser Science, Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany.
- National University Biomedical Research Institute, National University-Sudan, Air St. PO Box 3783, Khartoum, Sudan.
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6
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Mus F, Eilers BJ, Alleman AB, Kabasakal BV, Wells JN, Murray JW, Nocek BP, DuBois JL, Peters JW. Structural Basis for the Mechanism of ATP-Dependent Acetone Carboxylation. Sci Rep 2017; 7:7234. [PMID: 28775283 PMCID: PMC5543143 DOI: 10.1038/s41598-017-06973-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 06/21/2017] [Indexed: 01/07/2023] Open
Abstract
Microorganisms use carboxylase enzymes to form new carbon-carbon bonds by introducing carbon dioxide gas (CO2) or its hydrated form, bicarbonate (HCO3-), into target molecules. Acetone carboxylases (ACs) catalyze the conversion of substrates acetone and HCO3- to form the product acetoacetate. Many bicarbonate-incorporating carboxylases rely on the organic cofactor biotin for the activation of bicarbonate. ACs contain metal ions but not organic cofactors, and use ATP to activate substrates through phosphorylation. How the enzyme coordinates these phosphorylation events and new C-C bond formation in the absence of biotin has remained a mystery since these enzymes were discovered. The first structural rationale for acetone carboxylation is presented here, focusing on the 360 kDa (αβγ)2 heterohexameric AC from Xanthobacter autotrophicus in the ligand-free, AMP-bound, and acetate coordinated states. These structures suggest successive steps in a catalytic cycle revealing that AC undergoes large conformational changes coupled to substrate activation by ATP to perform C-C bond ligation at a distant Mn center. These results illustrate a new chemical strategy for the conversion of CO2 into biomass, a process of great significance to the global carbon cycle.
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Affiliation(s)
- Florence Mus
- 0000 0001 2157 6568grid.30064.31Insitutite of Biological Chemistry, Washington State University, Pullman, WA 99164 USA
| | - Brian J. Eilers
- 0000 0001 2156 6108grid.41891.35Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717 USA
| | - Alexander B. Alleman
- 0000 0001 2157 6568grid.30064.31Insitutite of Biological Chemistry, Washington State University, Pullman, WA 99164 USA
| | - Burak V. Kabasakal
- 0000 0001 2113 8111grid.7445.2Department of Life Sciences, Imperial College, London, SW7 2AZ UK
| | - Jennifer N. Wells
- 0000 0001 2113 8111grid.7445.2Department of Life Sciences, Imperial College, London, SW7 2AZ UK
| | - James W. Murray
- 0000 0001 2113 8111grid.7445.2Department of Life Sciences, Imperial College, London, SW7 2AZ UK
| | - Boguslaw P. Nocek
- 0000 0001 1939 4845grid.187073.aStructural Biology Center, Argonne National Laboratory, Argonne, IL 60439 USA
| | - Jennifer L. DuBois
- 0000 0001 2156 6108grid.41891.35Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717 USA
| | - John W. Peters
- 0000 0001 2157 6568grid.30064.31Insitutite of Biological Chemistry, Washington State University, Pullman, WA 99164 USA
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'Photosystem II: the water splitting enzyme of photosynthesis and the origin of oxygen in our atmosphere'. Q Rev Biophys 2016; 49:e14. [PMID: 27659174 DOI: 10.1017/s0033583516000093] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
About 3 billion years ago an enzyme emerged which would dramatically change the chemical composition of our planet and set in motion an unprecedented explosion in biological activity. This enzyme used solar energy to power the thermodynamically and chemically demanding reaction of water splitting. In so doing it provided biology with an unlimited supply of reducing equivalents needed to convert carbon dioxide into the organic molecules of life while at the same time produced oxygen to transform our planetary atmosphere from an anaerobic to an aerobic state. The enzyme which facilitates this reaction and therefore underpins virtually all life on our planet is known as Photosystem II (PSII). It is a pigment-binding, multisubunit protein complex embedded in the lipid environment of the thylakoid membranes of plants, algae and cyanobacteria. Today we have detailed understanding of the structure and functioning of this key and unique enzyme. The journey to this level of knowledge can be traced back to the discovery of oxygen itself in the 18th-century. Since then there has been a sequence of mile stone discoveries which makes a fascinating story, stretching over 200 years. But it is the last few years that have provided the level of detail necessary to reveal the chemistry of water oxidation and O-O bond formation. In particular, the crystal structure of the isolated PSII enzyme has been reported with ever increasing improvement in resolution. Thus the organisational and structural details of its many subunits and cofactors are now well understood. The water splitting site was revealed as a cluster of four Mn ions and a Ca ion surrounded by amino-acid side chains, of which seven provide direct ligands to the metals. The metal cluster is organised as a cubane structure composed of three Mn ions and a Ca2+ linked by oxo-bonds with the fourth Mn ion attached to the cubane. This structure has now been synthesised in a non-protein environment suggesting that it is a totally inorganic precursor for the evolution of the photosynthetic oxygen-evolving complex. In summary, the overall structure of the catalytic site has given a framework on which to build a mechanistic scheme for photosynthetic dioxygen generation and at the same time provide a blue-print and incentive to develop catalysts for artificial photo-electrochemical systems to split water and generate renewable solar fuels.
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Kato Y, Noguchi T. Long-Range Interaction between the Mn4CaO5 Cluster and the Non-heme Iron Center in Photosystem II as Revealed by FTIR Spectroelectrochemistry. Biochemistry 2014; 53:4914-23. [DOI: 10.1021/bi500549b] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Yuki Kato
- Division of Material Science,
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science,
Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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9
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Yano J, Yachandra V. Mn4Ca cluster in photosynthesis: where and how water is oxidized to dioxygen. Chem Rev 2014; 114:4175-205. [PMID: 24684576 PMCID: PMC4002066 DOI: 10.1021/cr4004874] [Citation(s) in RCA: 476] [Impact Index Per Article: 47.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Indexed: 12/25/2022]
Affiliation(s)
- Junko Yano
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| | - Vittal Yachandra
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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10
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Barber J. Photosystem II: Its function, structure, and implications for artificial photosynthesis. BIOCHEMISTRY (MOSCOW) 2014; 79:185-96. [DOI: 10.1134/s0006297914030031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Deák Z, Sass L, Kiss E, Vass I. Characterization of wave phenomena in the relaxation of flash-induced chlorophyll fluorescence yield in cyanobacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1522-32. [PMID: 24434028 DOI: 10.1016/j.bbabio.2014.01.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 12/30/2013] [Accepted: 01/07/2014] [Indexed: 12/25/2022]
Abstract
Fluorescence yield relaxation following a light pulse was studied in various cyanobacteria under aerobic and microaerobic conditions. In Synechocystis PCC 6803 fluorescence yield decays in a monotonous fashion under aerobic conditions. However, under microaerobic conditions the decay exhibits a wave feature showing a dip at 30-50 ms after the flash followed by a transient rise, reaching maximum at ~1s, before decaying back to the initial level. The wave phenomenon can also be observed under aerobic conditions in cells preilluminated with continuous light. Illumination preconditions cells for the wave phenomenon transiently: for few seconds in Synechocystis PCC 6803, but up to one hour in Thermosynechocystis elongatus BP-1. The wave is eliminated by inhibition of plastoquinone binding either to the QB site of Photosystem-II or the Qo site of cytochrome b6f complex by 3-(3',4'-dichlorophenyl)-1,1-dimethylurea or 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone, respectively. The wave is also absent in mutants, which lack either Photosystem-I or the NAD(P)H-quinone oxidoreductase (NDH-1) complex. Monitoring the redox state of the plastoquinone pool revealed that the dip of the fluorescence wave corresponds to transient oxidation, whereas the following rise to re-reduction of the plastoquinone pool. It is concluded that the unusual wave feature of fluorescence yield relaxation reflects transient oxidation of highly reduced plastoquinone pool by Photosystem-I followed by its re-reduction from stromal components via the NDH-1 complex, which is transmitted back to the fluorescence yield modulator primary quinone electron acceptor via charge equilibria. Potential applications of the wave phenomenon in studying photosynthetic and respiratory electron transport are discussed. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
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Affiliation(s)
- Zsuzsanna Deák
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Temesvari krt. 62, 6726 Szeged, Hungary
| | - László Sass
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Temesvari krt. 62, 6726 Szeged, Hungary
| | - Eva Kiss
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Temesvari krt. 62, 6726 Szeged, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre of the Hungarian Academy of Sciences, Temesvari krt. 62, 6726 Szeged, Hungary.
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12
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van Oort B, Kargul J, Maghlaoui K, Barber J, van Amerongen H. Fluorescence kinetics of PSII crystals containing Ca(2+) or Sr(2+) in the oxygen evolving complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:264-9. [PMID: 24269510 DOI: 10.1016/j.bbabio.2013.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 11/06/2013] [Accepted: 11/12/2013] [Indexed: 12/11/2022]
Abstract
Photosystem II (PSII) is the pigment-protein complex which converts sunlight energy into chemical energy by catalysing the process of light-driven oxidation of water into reducing equivalents in the form of protons and electrons. Three-dimensional structures from x-ray crystallography have been used extensively to model these processes. However, the crystal structures are not necessarily identical to those of the solubilised complexes. Here we compared picosecond fluorescence of solubilised and crystallised PSII core particles isolated from the thermophilic cyanobacterium Thermosynechococcus elongatus. The fluorescence of the crystals is sensitive to the presence of artificial electron acceptors (K3Fe(CN)3) and electron transport inhibitors (DCMU). In PSII with reaction centres in the open state, the picosecond fluorescence of PSII crystals and solubilised PSII is indistinguishable. Additionally we compared picosecond fluorescence of native PSII with PSII in which Ca(2) in the oxygen evolving complex (OEC) is biosynthetically replaced by Sr(2+). With the Sr(2+) replaced OEC the average fluorescence decay slows down slightly (81ps to 85ps), and reaction centres are less readily closed, indicating that both energy transfer/trapping and electron transfer are affected by the replacement.
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Affiliation(s)
- Bart van Oort
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
| | - Joanna Kargul
- Department of Plant Molecular Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
| | | | - James Barber
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London SW7 2AZ, UK
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P. O. Box 8128, 6700 ET Wageningen, The Netherlands
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13
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Krupnik T, Kotabová E, van Bezouwen LS, Mazur R, Garstka M, Nixon PJ, Barber J, Kaňa R, Boekema EJ, Kargul J. A reaction center-dependent photoprotection mechanism in a highly robust photosystem II from an extremophilic red alga, Cyanidioschyzon merolae. J Biol Chem 2013; 288:23529-42. [PMID: 23775073 DOI: 10.1074/jbc.m113.484659] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Members of the rhodophytan order Cyanidiales are unique among phototrophs in their ability to live in extremely low pH levels and moderately high temperatures. The photosynthetic apparatus of the red alga Cyanidioschyzon merolae represents an intermediate type between cyanobacteria and higher plants, suggesting that this alga may provide the evolutionary link between prokaryotic and eukaryotic phototrophs. Although we now have a detailed structural model of photosystem II (PSII) from cyanobacteria at an atomic resolution, no corresponding structure of the eukaryotic PSII complex has been published to date. Here we report the isolation and characterization of a highly active and robust dimeric PSII complex from C. merolae. We show that this complex is highly stable across a range of extreme light, temperature, and pH conditions. By measuring fluorescence quenching properties of the isolated C. merolae PSII complex, we provide the first direct evidence of pH-dependent non-photochemical quenching in the red algal PSII reaction center. This type of quenching, together with high zeaxanthin content, appears to underlie photoprotection mechanisms that are efficiently employed by this robust natural water-splitting complex under excess irradiance. In order to provide structural details of this eukaryotic form of PSII, we have employed electron microscopy and single particle analyses to obtain a 17 Å map of the C. merolae PSII dimer in which we locate the position of the protein mass corresponding to the additional extrinsic protein stabilizing the oxygen-evolving complex, PsbQ'. We conclude that this lumenal subunit is present in the vicinity of the CP43 protein, close to the membrane plane.
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Affiliation(s)
- Tomasz Krupnik
- Department of Plant Molecular Physiology, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland
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Structure of Sr-substituted photosystem II at 2.1 A resolution and its implications in the mechanism of water oxidation. Proc Natl Acad Sci U S A 2013; 110:3889-94. [PMID: 23426624 DOI: 10.1073/pnas.1219922110] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Oxygen-evolving complex of photosystem II (PSII) is a tetra-manganese calcium penta-oxygenic cluster (Mn4CaO5) catalyzing light-induced water oxidation through several intermediate states (S-states) by a mechanism that is not fully understood. To elucidate the roles of Ca(2+) in this cluster and the possible location of water substrates in this process, we crystallized Sr(2+)-substituted PSII from Thermosynechococcus vulcanus, analyzed its crystal structure at a resolution of 2.1 Å, and compared it with the 1.9 Å structure of native PSII. Our analysis showed that the position of Sr was moved toward the outside of the cubane structure of the Mn4CaO5-cluster relative to that of Ca(2+), resulting in a general elongation of the bond distances between Sr and its surrounding atoms compared with the corresponding distances in the Ca-containing cluster. In particular, we identified an apparent elongation in the bond distance between Sr and one of the two terminal water ligands of Ca(2+), W3, whereas that of the Sr-W4 distance was not much changed. This result may contribute to the decrease of oxygen evolution upon Sr(2+)-substitution, and suggests a weak binding and rather mobile nature of this particular water molecule (W3), which in turn implies the possible involvement of this water molecule as a substrate in the O-O bond formation. In addition, the PsbY subunit, which was absent in the 1.9 Å structure of native PSII, was found in the Sr-PSII structure.
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Kato Y, Shibamoto T, Yamamoto S, Watanabe T, Ishida N, Sugiura M, Rappaport F, Boussac A. Influence of the PsbA1/PsbA3, Ca2+/Sr2+ and Cl−/Br− exchanges on the redox potential of the primary quinone QA in Photosystem II from Thermosynechococcus elongatus as revealed by spectroelectrochemistry. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1998-2004. [PMID: 22721916 DOI: 10.1016/j.bbabio.2012.06.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 06/09/2012] [Accepted: 06/11/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Yuki Kato
- Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
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Boussac A, Ishida N, Sugiura M, Rappaport F. Probing the role of chloride in Photosystem II from Thermosynechococcus elongatus by exchanging chloride for iodide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:802-10. [DOI: 10.1016/j.bbabio.2012.02.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 02/21/2012] [Accepted: 02/24/2012] [Indexed: 11/29/2022]
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Su JH, Cox N, Ames W, Pantazis DA, Rapatskiy L, Lohmiller T, Kulik LV, Dorlet P, Rutherford AW, Neese F, Boussac A, Lubitz W, Messinger J. The electronic structures of the S(2) states of the oxygen-evolving complexes of photosystem II in plants and cyanobacteria in the presence and absence of methanol. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2011; 1807:829-40. [PMID: 21406177 DOI: 10.1016/j.bbabio.2011.03.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 03/02/2011] [Accepted: 03/04/2011] [Indexed: 01/25/2023]
Abstract
The electronic properties of the Mn(4)O(x)Ca cluster in the S(2) state of the oxygen-evolving complex (OEC) were studied using X- and Q-band EPR and Q-band (55)Mn-ENDOR using photosystem II preparations isolated from the thermophilic cyanobacterium T. elongatus and higher plants (spinach). The data presented here show that there is very little difference between the two species. Specifically it is shown that: (i) only small changes are seen in the fitted isotropic hyperfine values, suggesting that there is no significant difference in the overall spin distribution (electronic coupling scheme) between the two species; (ii) the inferred fine-structure tensor of the only Mn(III) ion in the cluster is of the same magnitude and geometry for both species types, suggesting that the Mn(III) ion has the same coordination sphere in both sample preparations; and (iii) the data from both species are consistent with only one structural model available in the literature, namely the Siegbahn structure [Siegbahn, P. E. M. Accounts Chem. Res.2009, 42, 1871-1880, Pantazis, D. A. et al., Phys. Chem. Chem. Phys.2009, 11, 6788-6798]. These measurements were made in the presence of methanol because it confers favorable magnetic relaxation properties to the cluster that facilitate pulse-EPR techniques. In the absence of methanol the separation of the ground state and the first excited state of the spin system is smaller. For cyanobacteria this effect is minor but in plant PS II it leads to a break-down of the S(T)=½ spin model of the S(2) state. This suggests that the methanol-OEC interaction is species dependent. It is proposed that the effect of small organic solvents on the electronic structure of the cluster is to change the coupling between the outer Mn (Mn(A)) and the other three Mn ions that form the trimeric part of the cluster (Mn(B), Mn(C), Mn(D)), by perturbing the linking bis-μ-oxo bridge. The flexibility of this bridging unit is discussed with regard to the mechanism of O-O bond formation.
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Affiliation(s)
- Ji-Hu Su
- Max-Planck-Institut für Bioanorganische Chemie, D-45470 Mülheim an der Ruhr, Germany
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Yachandra VK, Yano J. Calcium in the oxygen-evolving complex: structural and mechanistic role determined by X-ray spectroscopy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 104:51-9. [PMID: 21524917 DOI: 10.1016/j.jphotobiol.2011.02.019] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 02/22/2011] [Accepted: 02/24/2011] [Indexed: 11/25/2022]
Abstract
This review describes the results from X-ray Absorption Spectroscopy studies that have contributed to an understanding of the role of Ca in the photosynthetic water-oxidation reaction. The results include the first Mn, Ca and Sr X-ray spectroscopy studies using Ca or Sr-substituted PS II samples that established the presence of a MnCa heteronuclear structure and its orientation, and the most recent Sr X-ray spectroscopy study using biosynthetically prepared Sr-containing PS II in the various S-states that provide important insights into the requirement for Ca in the mechanism of the Mn(4)Ca catalytic center.
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Affiliation(s)
- Vittal K Yachandra
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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Cox N, Rapatskiy L, Su JH, Pantazis DA, Sugiura M, Kulik L, Dorlet P, Rutherford AW, Neese F, Boussac A, Lubitz W, Messinger J. Effect of Ca2+/Sr2+ substitution on the electronic structure of the oxygen-evolving complex of photosystem II: a combined multifrequency EPR, 55Mn-ENDOR, and DFT study of the S2 state. J Am Chem Soc 2011; 133:3635-48. [PMID: 21341708 DOI: 10.1021/ja110145v] [Citation(s) in RCA: 182] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The electronic structures of the native Mn(4)O(x)Ca cluster and the biosynthetically substituted Mn(4)O(x)Sr cluster of the oxygen evolving complex (OEC) of photosystem II (PSII) core complexes isolated from Thermosynechococcus elongatus, poised in the S(2) state, were studied by X- and Q-band CW-EPR and by pulsed Q-band (55)Mn-ENDOR spectroscopy. Both wild type and tyrosine D less mutants grown photoautotrophically in either CaCl(2) or SrCl(2) containing media were measured. The obtained CW-EPR spectra of the S(2) state displayed the characteristic, clearly noticeable differences in the hyperfine pattern of the multiline EPR signal [Boussac et al. J. Biol. Chem.2004, 279, 22809-22819]. In sharp contrast, the manganese ((55)Mn) ENDOR spectra of the Ca and Sr forms of the OEC were remarkably similar. Multifrequency simulations of the X- and Q-band CW-EPR and (55)Mn-pulsed ENDOR spectra using the Spin Hamiltonian formalism were performed to investigate this surprising result. It is shown that (i) all four manganese ions contribute to the (55)Mn-ENDOR spectra; (ii) only small changes are seen in the fitted isotropic hyperfine values for the Ca(2+) and Sr(2+) containing OEC, suggesting that there is no change in the overall spin distribution (electronic coupling scheme) upon Ca(2+)/Sr(2+) substitution; (iii) the changes in the CW-EPR hyperfine pattern can be explained by a small decrease in the anisotropy of at least two hyperfine tensors. It is proposed that modifications at the Ca(2+) site may modulate the fine structure tensor of the Mn(III) ion. DFT calculations support the above conclusions. Our data analysis also provides strong support for the notion that in the S(2) state the coordination of the Mn(III) ion is square-pyramidal (5-coordinate) or octahedral (6-coordinate) with tetragonal elongation. In addition, it is shown that only one of the currently published OEC models, the Siegbahn structure [Siegbahn, P. E. M. Acc. Chem. Res.2009, 42, 1871-1880, Pantazis, D. A. et al. Phys. Chem. Chem. Phys.2009, 11, 6788-6798], is consistent with all data presented here. These results provide important information for the structure of the OEC and the water-splitting mechanism. In particular, the 5-coordinate Mn(III) is a potential site for substrate 'water' (H(2)O, OH(-)) binding. Its location within the cuboidal structural unit, as opposed to the external 'dangler' position, may have important consequences for the mechanism of O-O bond formation.
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Affiliation(s)
- Nicholas Cox
- Max-Planck-Institut für Bioanorganische Chemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany.
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Ren Y, Zhang C, Zhao J. Substitution of chloride by bromide modifies the low-temperature tyrosine Z oxidation in active photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1421-7. [PMID: 20206122 DOI: 10.1016/j.bbabio.2010.02.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2009] [Revised: 01/29/2010] [Accepted: 02/23/2010] [Indexed: 11/19/2022]
Abstract
Chloride is an essential cofactor for photosynthetic water oxidation. However, its location and functional roles in active photosystem II are still a matter of debate. We have investigated this issue by studying the effects of Cl- replacement by Br- in active PSII. In Br- substituted samples, Cl- is effectively replaced by Br- in the presence of 1.2 M NaBr under room light with protection of anaerobic atmosphere followed by dialysis. The following results have been obtained. i) The oxygen-evolving activities of the Br--PSII samples are significantly lower than that of the Cl--PSII samples; ii) The same S2 multiline EPR signals are observed in both Br- and Cl--PSII samples; iii) The amplitudes of the visible light induced S1TyrZ* and S2TyrZ* EPR signals are significantly decreased after Br- substitution; the S1TyrZ* EPR signal is up-shifted about 8G, whereas the S2TyrZ* signal is down-shifted about 12 G after Br- substitution. These results imply that the redox properties of TyrZ and spin interactions between TyrZ* and Mn-cluster could be significantly modified due to Br- substitution. It is suggested that Cl-/Br- probably coordinates to the Ca2+ ion of the Mn-cluster in active photosystem II.
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Affiliation(s)
- Yanan Ren
- Laboratory of Photochemistry, Beijing National Laboratory of Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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Renger G, Renger T. Photosystem II: The machinery of photosynthetic water splitting. PHOTOSYNTHESIS RESEARCH 2008; 98:53-80. [PMID: 18830685 DOI: 10.1007/s11120-008-9345-7] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Accepted: 07/29/2008] [Indexed: 05/26/2023]
Abstract
This review summarizes our current state of knowledge on the structural organization and functional pattern of photosynthetic water splitting in the multimeric Photosystem II (PS II) complex, which acts as a light-driven water: plastoquinone-oxidoreductase. The overall process comprises three types of reaction sequences: (1) photon absorption and excited singlet state trapping by charge separation leading to the ion radical pair [Formula: see text] formation, (2) oxidative water splitting into four protons and molecular dioxygen at the water oxidizing complex (WOC) with P680+* as driving force and tyrosine Y(Z) as intermediary redox carrier, and (3) reduction of plastoquinone to plastoquinol at the special Q(B) binding site with Q(A)-* acting as reductant. Based on recent progress in structure analysis and using new theoretical approaches the mechanism of reaction sequence (1) is discussed with special emphasis on the excited energy transfer pathways and the sequence of charge transfer steps: [Formula: see text] where (1)(RC-PC)* denotes the excited singlet state (1)P680* of the reaction centre pigment complex. The structure of the catalytic Mn(4)O(X)Ca cluster of the WOC and the four step reaction sequence leading to oxidative water splitting are described and problems arising for the electronic configuration, in particular for the nature of redox state S(3), are discussed. The unravelling of the mode of O-O bond formation is of key relevance for understanding the mechanism of the process. This problem is not yet solved. A multistate model is proposed for S(3) and the functional role of proton shifts and hydrogen bond network(s) is emphasized. Analogously, the structure of the Q(B) site for PQ reduction to PQH(2) and the energetic and kinetics of the two step redox reaction sequence are described. Furthermore, the relevance of the protein dynamics and the role of water molecules for its flexibility are briefly outlined. We end this review by presenting future perspectives on the water oxidation process.
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Affiliation(s)
- Gernot Renger
- Max Volmer Laboratory for Biophysical Chemistry, Berlin Institute of Technology, Berlin, Germany.
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Miqyass M, Marosvölgyi MA, Nagel Z, Yocum CF, van Gorkom HJ. S-State Dependence of the Calcium Requirement and Binding Characteristics in the Oxygen-Evolving Complex of Photosystem II. Biochemistry 2008; 47:7915-24. [DOI: 10.1021/bi8006059] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohamed Miqyass
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands, and Departments of MCD Biology and Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Marcell A. Marosvölgyi
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands, and Departments of MCD Biology and Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Zachary Nagel
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands, and Departments of MCD Biology and Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Charles F. Yocum
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands, and Departments of MCD Biology and Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1048
| | - Hans J. van Gorkom
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, NL-2300 RA Leiden, The Netherlands, and Departments of MCD Biology and Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1048
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Abstract
The oxygen in our atmosphere is derived from and maintained by the water-splitting process of photosynthesis. The enzyme that facilitates this reaction and therefore underpins virtually all life on our planet is known as photosystem II (PSII). It is a multisubunit enzyme embedded in the lipid environment of the thylakoid membranes of plants, algae, and cyanobacteria. Powered by light, PSII catalyzes the chemically and thermodynamically demanding reaction of water splitting. In so doing, it releases molecular oxygen into the atmosphere and provides the reducing equivalents required for the conversion of carbon dioxide into the organic molecules of life. Recently, a fully refined structure of an isolated 700 kDa cyanobacterial dimeric PSII complex was elucidated by X-ray crystallography, which gave organizational and structural details of the 19 subunits (16 intrinsic and 3 extrinsic) that make up each monomer and provided information about the position and protein environments of the many different cofactors it binds. The water-splitting site was revealed as a cluster of four Mn ions and a Ca ion surrounded by amino acid side chains, of which six or seven form direct ligands to the metals. The metal cluster was originally modeled as a cubane-like structure composed of three Mn ions and the Ca (2+) linked by oxo bonds and the fourth Mn attached to the cubane via one of its O atoms. New data from X-ray diffraction and X-ray spectroscopy suggest some alternative arrangements. Nevertheless, all of the models are sufficiently similar to provide a basis for discussing the chemistry by which PSII splits water and makes oxygen.
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Affiliation(s)
- James Barber
- Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, UK.
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Boussac A, Sugiura M, Lai TL, Rutherford AW. Low-temperature photochemistry in photosystem II from Thermosynechococcus elongatus induced by visible and near-infrared light. Philos Trans R Soc Lond B Biol Sci 2008; 363:1203-10; discussion 1210. [PMID: 17965006 DOI: 10.1098/rstb.2007.2216] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The active site for water oxidation in photosystem II (PSII) consists of a Mn4Ca cluster close to a redox-active tyrosine residue (TyrZ). The enzyme cycles through five sequential oxidation states (S0 to S4) in the water oxidation process. Earlier electron paramagnetic resonance (EPR) work showed that metalloradical states, probably arising from the Mn4 cluster interacting with TyrZ., can be trapped by illumination of the S0, S1 and S2 states at cryogenic temperatures. The EPR signals reported were attributed to S0TyrZ., S1TyrZ. and S2TyrZ., respectively. The equivalent states were examined here by EPR in PSII isolated from Thermosynechococcus elongatus with either Sr or Ca associated with the Mn4 cluster. In order to avoid spectral contributions from the second tyrosyl radical, TyrD., PSII was used in which Tyr160 of D2 was replaced by phenylalanine. We report that the metalloradical signals attributed to TyrZ. interacting with the Mn cluster in S0, S1, S2 and also probably the S3 states are all affected by the presence of Sr. Ca/Sr exchange also affects the non-haem iron which is situated approximately 44 A units away from the Ca site. This could relate to the earlier reported modulation of the potential of QA by the occupancy of the Ca site. It is also shown that in the S3 state both visible and near-infrared light are able to induce a similar Mn photochemistry.
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Affiliation(s)
- Alain Boussac
- DSV, iBiTec-s, SB2 SM, URA CNRS 2096, CEA Saclay, 91191 Gif sur Yvette, Cedex, France.
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Barber J, Murray JW. The structure of the Mn4Ca2+ cluster of photosystem II and its protein environment as revealed by X-ray crystallography. Philos Trans R Soc Lond B Biol Sci 2008; 363:1129-38; discussion 1137-8. [PMID: 17971332 DOI: 10.1098/rstb.2007.2208] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The location, structure and protein environment of the Mn4Ca2+ cluster, which catalyses the light-driven, water-splitting reaction of photosystem II, has been revealed by X-ray crystallography. However, owing to the low resolutions of the crystal structures reported to date, and the possibility of radiation damage at the catalytic centre, the precise position of each metal ion remains unknown. To some extent, these problems have been overcome by applying spectroscopic techniques like extended X-ray absorption fine structure. Taking into account the most recent results obtained with these two X-ray-based techniques, we have attempted to refine models of the structure of the Mn4Ca2+ cluster and its protein environment.
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Affiliation(s)
- James Barber
- Division of Molecular Biosciences, Imperial College London, London SW7 2AZ, UK.
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Ishida N, Sugiura M, Rappaport F, Lai TL, Rutherford AW, Boussac A. Biosynthetic Exchange of Bromide for Chloride and Strontium for Calcium in the Photosystem II Oxygen-evolving Enzymes. J Biol Chem 2008; 283:13330-40. [DOI: 10.1074/jbc.m710583200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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Mishra A, Pushkar Y, Yano J, Yachandra VK, Wernsdorfer W, Abboud KA, Christou G. Single-molecule magnetism properties of the first strontium-manganese cluster [SrMn14O11(OMe)3(O2CPh)18(MeCN)2]. Inorg Chem 2008; 47:1940-8. [PMID: 18281933 DOI: 10.1021/ic701339p] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The preparation and properties of the first strontium-manganese molecular complex are described. The reaction of (NBu(n)4)[Mn4O2(O2CPh)9(H 2O)] (4Mn(III)) with Sr(ClO4)2 in MeCN/MeOH led to the isolation of [SrMn14O11(OMe)3(O2CPh)18(MeCN)2] ( 1; 13Mn(III), Mn(II)). The structure of 1 consists of two [Mn4O3(OMe)] cubane units attached to a central, near-planar, trinuclear [Mn3O4] unit, to which are also attached a Mn and a Sr above the plane and a [Mn2O(OMe)] rhomb below the plane. Peripheral ligation is provided by 18 bridging benzoate and two terminal MeCN groups. Variable-temperature and -field dc magnetization (M) data were collected in the 1.8-10 K and 0.1-4.0 T ranges and fit by matrix diagonalization methods to give S = 9/2, D = -0.50(5) cm(-1), and g = 1.88(10), where S is the ground-state spin and D is the axial zero-field splitting parameter. Magnetization versus dc field sweeps at various temperatures and scan rates exhibited hysteresis loops, confirming 1 to be a new single-molecule magnet. Because complex 1 is the initial molecular example of intimately associated Mn and Sr atoms, Sr EXAFS studies have been performed for the first time on a synthetic Sr-containing molecule. This has also allowed comparisons with the EXAFS data on the Sr-substituted water oxidizing complex (WOC) of Photosystem II (PS II), which contains a SrMn4 complex.
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Affiliation(s)
- Abhudaya Mishra
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
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