1
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Zhao Y, Deng L, Last RL, Hua W, Liu J. Psb28 protein is indispensable for stable accumulation of PSII core complexes in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024. [PMID: 38796842 DOI: 10.1111/tpj.16844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/24/2024] [Accepted: 05/07/2024] [Indexed: 05/29/2024]
Abstract
Enhancing the efficiency of photosynthesis represents a promising strategy to improve crop yields, with keeping the steady state of PSII being key to determining the photosynthetic performance. However, the mechanisms whereby the stability of PSII is maintained in oxygenic organisms remain to be explored. Here, we report that the Psb28 protein functions in regulating the homeostasis of PSII under different light conditions in Arabidopsis thaliana. The psb28 mutant is much smaller than the wild-type plants under normal growth light, which is due to its significantly reduced PSII activity. Similar defects were seen under low light and became more pronounced under photoinhibitory light. Notably, the amounts of PSII core complexes and core subunits are specifically decreased in psb28, whereas the abundance of other representative components of photosynthetic complexes remains largely unaltered. Although the PSII activity of psb28 was severely reduced when subjected to high light, its recovery from photoinactivation was not affected. By contrast, the degradation of PSII core protein subunits is dramatically accelerated in the presence of lincomycin. These results indicate that psb28 is defective in the photoprotection of PSII, which is consistent with the observation that the overall NPQ is much lower in psb28 compared to the wild type. Moreover, the Psb28 protein is associated with PSII core complexes and interacts mainly with the CP47 subunit of PSII core. Taken together, these findings reveal an important role for Psb28 in the protection and stabilization of PSII core in response to changes in light environments.
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Affiliation(s)
- Yuwei Zhao
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, 430062, China
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, Wuhan, 430070, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Linbin Deng
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, 430062, China
| | - Robert L Last
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, 48824, USA
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Wei Hua
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, 430062, China
| | - Jun Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan, 430062, China
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2
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Xiao Y, Huang G, You X, Zhu Q, Wang W, Kuang T, Han G, Sui SF, Shen JR. Structural insights into cyanobacterial photosystem II intermediates associated with Psb28 and Tsl0063. NATURE PLANTS 2021; 7:1132-1142. [PMID: 34226692 DOI: 10.1038/s41477-021-00961-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/03/2021] [Indexed: 05/07/2023]
Abstract
Photosystem II (PSII) is a multisubunit pigment-protein complex and catalyses light-induced water oxidation, leading to the conversion of light energy into chemical energy and the release of dioxygen. We analysed the structures of two Psb28-bound PSII intermediates, Psb28-RC47 and Psb28-PSII, purified from a psbV-deletion strain of the thermophilic cyanobacterium Thermosynechococcus vulcanus, using cryo-electron microscopy. Both Psb28-RC47 and Psb28-PSII bind one Psb28, one Tsl0063 and an unknown subunit. Psb28 is located at the cytoplasmic surface of PSII and interacts with D1, D2 and CP47, whereas Tsl0063 is a transmembrane subunit and binds at the side of CP47/PsbH. Substantial structural perturbations are observed at the acceptor side, which result in conformational changes of the quinone (QB) and non-haem iron binding sites and thus may protect PSII from photodamage during assembly. These results provide a solid structural basis for understanding the assembly process of native PSII.
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Affiliation(s)
- Yanan Xiao
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guoqiang Huang
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xin You
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China
| | - Qingjun Zhu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenda Wang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Tingyun Kuang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
| | - Sen-Fang Sui
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology & Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing, China.
- Department of Biology, Southern University of Science and Technology, Shenzhen, China.
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
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3
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Zabret J, Bohn S, Schuller SK, Arnolds O, Möller M, Meier-Credo J, Liauw P, Chan A, Tajkhorshid E, Langer JD, Stoll R, Krieger-Liszkay A, Engel BD, Rudack T, Schuller JM, Nowaczyk MM. Structural insights into photosystem II assembly. NATURE PLANTS 2021; 7:524-538. [PMID: 33846594 PMCID: PMC8094115 DOI: 10.1038/s41477-021-00895-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 03/04/2021] [Indexed: 05/07/2023]
Abstract
Biogenesis of photosystem II (PSII), nature's water-splitting catalyst, is assisted by auxiliary proteins that form transient complexes with PSII components to facilitate stepwise assembly events. Using cryo-electron microscopy, we solved the structure of such a PSII assembly intermediate from Thermosynechococcus elongatus at 2.94 Å resolution. It contains three assembly factors (Psb27, Psb28 and Psb34) and provides detailed insights into their molecular function. Binding of Psb28 induces large conformational changes at the PSII acceptor side, which distort the binding pocket of the mobile quinone (QB) and replace the bicarbonate ligand of non-haem iron with glutamate, a structural motif found in reaction centres of non-oxygenic photosynthetic bacteria. These results reveal mechanisms that protect PSII from damage during biogenesis until water splitting is activated. Our structure further demonstrates how the PSII active site is prepared for the incorporation of the Mn4CaO5 cluster, which performs the unique water-splitting reaction.
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Affiliation(s)
- Jure Zabret
- Department of Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Stefan Bohn
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Sandra K Schuller
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
- CryoEM of Molecular Machines, SYNMIKRO Research Center and Department of Chemistry, Philipps University of Marburg, Marburg, Germany
| | - Oliver Arnolds
- Biomolecular Spectroscopy and RUBiospek|NMR, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Madeline Möller
- Department of Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | | | - Pasqual Liauw
- Department of Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Aaron Chan
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Emad Tajkhorshid
- NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Julian D Langer
- Proteomics, Max Planck Institute of Biophysics, Frankfurt, Germany
- Proteomics, Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Raphael Stoll
- Biomolecular Spectroscopy and RUBiospek|NMR, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, Gif-sur-Yvette, France
| | - Benjamin D Engel
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Chemistry, Technical University of Munich, Garching, Germany
| | - Till Rudack
- Biospectroscopy, Center for Protein Diagnostics (ProDi), Ruhr University Bochum, Bochum, Germany.
- Department of Biophysics, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany.
| | - Jan M Schuller
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany.
- CryoEM of Molecular Machines, SYNMIKRO Research Center and Department of Chemistry, Philipps University of Marburg, Marburg, Germany.
| | - Marc M Nowaczyk
- Department of Plant Biochemistry, Faculty of Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany.
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4
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Pascual-Aznar G, Konert G, Bečkov M, Kotabov E, Gardian Z, Knoppov J, Bučinsk L, Kaňa R, Sobotka R, Komenda J. Psb35 Protein Stabilizes the CP47 Assembly Module and Associated High-Light Inducible Proteins during the Biogenesis of Photosystem II in the Cyanobacterium Synechocystis sp. PCC6803. PLANT & CELL PHYSIOLOGY 2021; 62:178-190. [PMID: 33258963 DOI: 10.1093/pcp/pcaa148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/16/2020] [Indexed: 05/07/2023]
Abstract
Photosystem II (PSII) is a large membrane protein complex performing primary charge separation in oxygenic photosynthesis. The biogenesis of PSII is a complicated process that involves a coordinated linking of assembly modules in a precise order. Each such module consists of one large chlorophyll (Chl)-binding protein, number of small membrane polypeptides, pigments and other cofactors. We isolated the CP47 antenna module from the cyanobacterium Synechocystis sp. PCC 6803 and found that it contains a 11-kDa protein encoded by the ssl2148 gene. This protein was named Psb35 and its presence in the CP47 module was confirmed by the isolation of FLAG-tagged version of Psb35. Using this pulldown assay, we showed that the Psb35 remains attached to CP47 after the integration of CP47 into PSII complexes. However, the isolated Psb35-PSIIs were enriched with auxiliary PSII assembly factors like Psb27, Psb28-1, Psb28-2 and RubA while they lacked the lumenal proteins stabilizing the PSII oxygen-evolving complex. In addition, the Psb35 co-purified with a large unique complex of CP47 and photosystem I trimer. The absence of Psb35 led to a lower accumulation and decreased stability of the CP47 antenna module and associated high-light-inducible proteins but did not change the growth rate of the cyanobacterium under the variety of light regimes. Nevertheless, in comparison with WT, the Psb35-less mutant showed an accelerated pigment bleaching during prolonged dark incubation. The results suggest an involvement of Psb35 in the life cycle of cyanobacterial Chl-binding proteins, especially CP47.
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Affiliation(s)
- Guillem Pascual-Aznar
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
- Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovsk� 1760, Česk� Budějovice 37005, Czech Republic
| | - Grzegorz Konert
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
| | - Martina Bečkov
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
| | - Eva Kotabov
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
| | - Zdenko Gardian
- Department of Molecular Biology and Genetics, Faculty of Science, University of South Bohemia, Branišovsk� 1760, Česk� Budějovice 37005, Czech Republic
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branišovsk� 31, Česk� Budějovice 37005, Czech Republic
| | - Jana Knoppov
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
| | - Lenka Bučinsk
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
| | - Radek Kaňa
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
| | - Roman Sobotka
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
| | - Josef Komenda
- Institute of Microbiology of the Czech Academy of Sciences, Centre Algatech, Opatovick� ml�n, Novohradsk� 237, Třeboň 37981, Czech Republic
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5
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Bečková M, Gardian Z, Yu J, Konik P, Nixon PJ, Komenda J. Association of Psb28 and Psb27 Proteins with PSII-PSI Supercomplexes upon Exposure of Synechocystis sp. PCC 6803 to High Light. MOLECULAR PLANT 2017; 10:62-72. [PMID: 27530366 DOI: 10.1016/j.molp.2016.08.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 06/29/2016] [Accepted: 08/04/2016] [Indexed: 05/23/2023]
Abstract
Formation of the multi-subunit oxygen-evolving photosystem II (PSII) complex involves a number of auxiliary protein factors. In this study we compared the localization and possible function of two homologous PSII assembly factors, Psb28-1 and Psb28-2, from the cyanobacterium Synechocystis sp. PCC 6803. We demonstrate that FLAG-tagged Psb28-2 is present in both the monomeric PSII core complex and a PSII core complex lacking the inner antenna CP43 (RC47), whereas Psb28-1 preferentially binds to RC47. When cells are exposed to increased irradiance, both tagged Psb28 proteins additionally associate with oligomeric forms of PSII and with PSII-PSI supercomplexes composed of trimeric photosystem I (PSI) and two PSII monomers as deduced from electron microscopy. The presence of the Psb27 accessory protein in these complexes suggests the involvement of PSI in PSII biogenesis, possibly by photoprotecting PSII through energy spillover. Under standard culture conditions, the distribution of PSII complexes is similar in the wild type and in each of the single psb28 null mutants except for loss of RC47 in the absence of Psb28-1. In comparison with the wild type, growth of mutants lacking Psb28-1 and Psb27, but not Psb28-2, was retarded under high-light conditions and, especially, intermittent high-light/dark conditions, emphasizing the physiological importance of PSII assembly factors for light acclimation.
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Affiliation(s)
- Martina Bečková
- Institute of Microbiology, Center Algatech, Opatovický mlýn, 37981 Třeboň, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - Zdenko Gardian
- Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic; Institute of Plant Molecular Biology, Biology Centre Academy of Sciences, Branišovská 31, 37005 České Budějovice, Czech Republic
| | - Jianfeng Yu
- Sir Ernst Chain Building-Wolfson Laboratories, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Peter Konik
- Institute of Microbiology, Center Algatech, Opatovický mlýn, 37981 Třeboň, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic
| | - Peter J Nixon
- Sir Ernst Chain Building-Wolfson Laboratories, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Josef Komenda
- Institute of Microbiology, Center Algatech, Opatovický mlýn, 37981 Třeboň, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 1760, 37005 České Budějovice, Czech Republic.
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6
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Heinz S, Liauw P, Nickelsen J, Nowaczyk M. Analysis of photosystem II biogenesis in cyanobacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:274-87. [PMID: 26592144 DOI: 10.1016/j.bbabio.2015.11.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/13/2015] [Accepted: 11/15/2015] [Indexed: 11/25/2022]
Abstract
Photosystem II (PSII), a large multisubunit membrane protein complex found in the thylakoid membranes of cyanobacteria, algae and plants, catalyzes light-driven oxygen evolution from water and reduction of plastoquinone. Biogenesis of PSII requires coordinated assembly of at least 20 protein subunits, as well as incorporation of various organic and inorganic cofactors. The stepwise assembly process is facilitated by numerous protein factors that have been identified in recent years. Further analysis of this process requires the development or refinement of specific methods for the identification of novel assembly factors and, in particular, elucidation of the unique role of each. Here we summarize current knowledge of PSII biogenesis in cyanobacteria, focusing primarily on the impact of methodological advances and innovations. This article is part of a Special Issue entitled Organization and dynamics of bioenergetic systems in bacteria, edited by Conrad Mullineaux.
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Affiliation(s)
- Steffen Heinz
- Molekulare Pflanzenwissenschaften, Biozentrum LMU München, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany
| | - Pasqual Liauw
- Biochemie der Pflanzen, Ruhr Universität Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Jörg Nickelsen
- Molekulare Pflanzenwissenschaften, Biozentrum LMU München, Großhaderner Str. 2-4, 82152 Planegg-Martinsried, Germany.
| | - Marc Nowaczyk
- Biochemie der Pflanzen, Ruhr Universität Bochum, Universitätsstr. 150, 44801 Bochum, Germany.
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7
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Bricker TM, Mummadisetti MP, Frankel LK. Recent advances in the use of mass spectrometry to examine structure/function relationships in photosystem II. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2015; 152:227-46. [PMID: 26390944 DOI: 10.1016/j.jphotobiol.2015.08.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 08/27/2015] [Accepted: 08/31/2015] [Indexed: 01/24/2023]
Abstract
Tandem mass spectrometry often coupled with chemical modification techniques, is developing into increasingly important tool in structural biology. These methods can provide important supplementary information concerning the structural organization and subunit make-up of membrane protein complexes, identification of conformational changes occurring during enzymatic reactions, identification of the location of posttranslational modifications, and elucidation of the structure of assembly and repair complexes. In this review, we will present a brief introduction to Photosystem II, tandem mass spectrometry and protein modification techniques that have been used to examine the photosystem. We will then discuss a number of recent case studies that have used these techniques to address open questions concerning PS II. These include the nature of subunit-subunit interactions within the phycobilisome, the interaction of phycobilisomes with Photosystem I and the Orange Carotenoid Protein, the location of CyanoQ, PsbQ and PsbP within Photosystem II, and the identification of phosphorylation and oxidative modification sites within the photosystem. Finally, we will discuss some of the future prospects for the use of these methods in examining other open questions in PS II structural biochemistry.
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Affiliation(s)
- Terry M Bricker
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, LA 70803, United States.
| | - Manjula P Mummadisetti
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, LA 70803, United States
| | - Laurie K Frankel
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, LA 70803, United States
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8
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Michoux F, Boehm M, Bialek W, Takasaka K, Maghlaoui K, Barber J, Murray JW, Nixon PJ. Crystal structure of CyanoQ from the thermophilic cyanobacterium Thermosynechococcus elongatus and detection in isolated photosystem II complexes. PHOTOSYNTHESIS RESEARCH 2014; 122:57-67. [PMID: 24838684 PMCID: PMC4180030 DOI: 10.1007/s11120-014-0010-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 04/28/2014] [Indexed: 05/23/2023]
Abstract
The PsbQ-like protein, termed CyanoQ, found in the cyanobacterium Synechocystis sp. PCC 6803 is thought to bind to the lumenal surface of photosystem II (PSII), helping to shield the Mn4CaO5 oxygen-evolving cluster. CyanoQ is, however, absent from the crystal structures of PSII isolated from thermophilic cyanobacteria raising the possibility that the association of CyanoQ with PSII might not be a conserved feature. Here, we show that CyanoQ (encoded by tll2057) is indeed expressed in the thermophilic cyanobacterium Thermosynechococcus elongatus and provide evidence in support of its assignment as a lipoprotein. Using an immunochemical approach, we show that CyanoQ co-purifies with PSII and is actually present in highly pure PSII samples used to generate PSII crystals. The absence of CyanoQ in the final crystal structure is possibly due to detachment of CyanoQ during crystallisation or its presence in sub-stoichiometric amounts. In contrast, the PsbP homologue, CyanoP, is severely depleted in isolated PSII complexes. We have also determined the crystal structure of CyanoQ from T. elongatus to a resolution of 1.6 Å. It lacks bound metal ions and contains a four-helix up-down bundle similar to the ones found in Synechocystis CyanoQ and spinach PsbQ. However, the N-terminal region and extensive lysine patch that are thought to be important for binding of PsbQ to PSII are not conserved in T. elongatus CyanoQ.
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Affiliation(s)
- Franck Michoux
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
- Present Address: Alkion Biopharma, 4 rue Pierre Fontaine, 91000 Evry, France
| | - Marko Boehm
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | - Wojciech Bialek
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | - Kenji Takasaka
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | - Karim Maghlaoui
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | - James Barber
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | - James W. Murray
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
| | - Peter J. Nixon
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories Imperial College London, South Kensington Campus, London, SW7 2AZ UK
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9
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Mabbitt PD, Wilbanks SM, Eaton-Rye JJ. Structure and function of the hydrophilic Photosystem II assembly proteins: Psb27, Psb28 and Ycf48. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 81:96-107. [PMID: 24656878 DOI: 10.1016/j.plaphy.2014.02.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 02/16/2014] [Indexed: 05/23/2023]
Abstract
Photosystem II (PS II) is a macromolecular complex responsible for light-driven oxidation of water and reduction of plastoquinone as part of the photosynthetic electron transport chain found in thylakoid membranes. Each PS II complex is composed of at least 20 protein subunits and over 80 cofactors. The biogenesis of PS II requires further hydrophilic and membrane-spanning proteins which are not part of the active holoenzyme. Many of these biogenesis proteins make transient interactions with specific PS II assembly intermediates: sometimes these are essential for biogenesis while in other examples they are required for optimizing assembly of the mature complex. In this review the function and structure of the Psb27, Psb28 and Ycf48 hydrophilic assembly factors is discussed by combining structural, biochemical and physiological information. Each of these assembly factors has homologues in all oxygenic photosynthetic organisms. We provide a simple overview for the roles of these protein factors in cyanobacterial PS II assembly emphasizing their participation in both photosystem biogenesis and recovery from photodamage.
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Affiliation(s)
- Peter D Mabbitt
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand
| | - Sigurd M Wilbanks
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand.
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