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Gisriel CJ, Flesher DA, Shen G, Wang J, Ho MY, Brudvig GW, Bryant DA. Structure of a photosystem I-ferredoxin complex from a marine cyanobacterium provides insights into far-red light photoacclimation. J Biol Chem 2022; 298:101408. [PMID: 34793839 PMCID: PMC8689207 DOI: 10.1016/j.jbc.2021.101408] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 01/08/2023] Open
Abstract
Far-red light photoacclimation exhibited by some cyanobacteria allows these organisms to use the far-red region of the solar spectrum (700-800 nm) for photosynthesis. Part of this process includes the replacement of six photosystem I (PSI) subunits with isoforms that confer the binding of chlorophyll (Chl) f molecules that absorb far-red light (FRL). However, the exact sites at which Chl f molecules are bound are still challenging to determine. To aid in the identification of Chl f-binding sites, we solved the cryo-EM structure of PSI from far-red light-acclimated cells of the cyanobacterium Synechococcus sp. PCC 7335. We identified six sites that bind Chl f with high specificity and three additional sites that are likely to bind Chl f at lower specificity. All of these binding sites are in the core-antenna regions of PSI, and Chl f was not observed among the electron transfer cofactors. This structural analysis also reveals both conserved and nonconserved Chl f-binding sites, the latter of which exemplify the diversity in FRL-PSI among species. We found that the FRL-PSI structure also contains a bound soluble ferredoxin, PetF1, at low occupancy, which suggests that ferredoxin binds less transiently than expected according to the canonical view of ferredoxin-binding to facilitate electron transfer. We suggest that this may result from structural changes in FRL-PSI that occur specifically during FRL photoacclimation.
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Affiliation(s)
| | - David A Flesher
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Gaozhong Shen
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Ming-Yang Ho
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut, USA; Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA.
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Modulation of photosynthesis and other proteins during water-stress. Mol Biol Rep 2021; 48:3681-3693. [PMID: 33856605 DOI: 10.1007/s11033-021-06329-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/31/2021] [Indexed: 10/25/2022]
Abstract
Protein changes under drought or water stress conditions have been widely investigated. These investigations have given us enormous understanding of how drought is manifested in plants and how plants respond and adopt to such conditions. Chlorophyll fluoroescence, gas exchange, OMICS, biochemical and molecular analyses have shed light on regulation of physiology and photosynthesis of plants under drought. Use of proteomics has greatly increased the repertoire of drought-associated proteins which nevertheless, need to be investigated for their mechanistic and functional roles. Roles of such proteins have been succinctly discussed in various review articles, however more information on their functional role in countering drought is needed. In this review, recent developments in the field, alterations in the abundance of plant proteins in response to drought, monitored through numerous proteomic and immuno-blot analyses, and how these could affect plants growth and development, are discussed.
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Kölsch A, Radon C, Golub M, Baumert A, Bürger J, Mielke T, Lisdat F, Feoktystov A, Pieper J, Zouni A, Wendler P. Current limits of structural biology: The transient interaction between cytochrome c 6 and photosystem I. Curr Res Struct Biol 2020; 2:171-179. [PMID: 34235477 PMCID: PMC8244401 DOI: 10.1016/j.crstbi.2020.08.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/11/2020] [Accepted: 08/17/2020] [Indexed: 12/22/2022] Open
Abstract
Trimeric photosystem I from the cyanobacterium Thermosynechococcus elongatus (TePSI) is an intrinsic membrane protein, which converts solar energy into electrical energy by oxidizing the soluble redox mediator cytochrome c 6 (Cyt c 6 ) and reducing ferredoxin. Here, we use cryo-electron microscopy and small angle neutron scattering (SANS) to characterize the transient binding of Cyt c 6 to TePSI. The structure of TePSI cross-linked to Cyt c 6 was solved at a resolution of 2.9 Å and shows additional cofactors as well as side chain density for 84% of the peptide chain of subunit PsaK, revealing a hydrophobic, membrane intrinsic loop that enables binding of associated proteins. Due to the poor binding specificity, Cyt c 6 could not be localized with certainty in our cryo-EM analysis. SANS measurements confirm that Cyt c 6 does not bind to TePSI at protein concentrations comparable to those for cross-linking. However, SANS data indicate a complex formation between TePSI and the non-native mitochondrial cytochrome from horse heart (Cyt c HH ). Our study pinpoints the difficulty of identifying very small binding partners (less than 5% of the overall size) in EM structures when binding affinities are poor. We relate our results to well resolved co-structures with known binding affinities and recommend confirmatory methods for complexes with K M values higher than 20 μM.
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Affiliation(s)
- A. Kölsch
- Department of Biology, Humboldt–Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - C. Radon
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany
| | - M. Golub
- Institute of Physics, University of Tartu, Wilhelm Ostwaldi 1, 50411, Tartu, Estonia
| | - A. Baumert
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany
| | - J. Bürger
- Max-Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195, Berlin, Germany
- Charité, Institut für Medizinische Physik und Biophysik, Charitéplatz 1, 10117, Berlin, Germany
| | - T. Mielke
- Max-Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195, Berlin, Germany
| | - F. Lisdat
- Institute of Applied Life Sciences, Technical University of Applied Sciences Wildau, Hochschulring 1, 15745, Wildau, Germany
| | - A. Feoktystov
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstr. 1, 85748, Garching, Germany
| | - J. Pieper
- Institute of Physics, University of Tartu, Wilhelm Ostwaldi 1, 50411, Tartu, Estonia
| | - A. Zouni
- Department of Biology, Humboldt–Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - P. Wendler
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, 14476, Potsdam-Golm, Germany
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Marco P, Kozuleva M, Eilenberg H, Mazor Y, Gimeson P, Kanygin A, Redding K, Weiner I, Yacoby I. Binding of ferredoxin to algal photosystem I involves a single binding site and is composed of two thermodynamically distinct events. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:234-243. [DOI: 10.1016/j.bbabio.2018.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/07/2018] [Accepted: 01/08/2018] [Indexed: 10/18/2022]
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Veit S, Nagadoi A, Rögner M, Rexroth S, Stoll R, Ikegami T. The cyanobacterial cytochrome b6f subunit PetP adopts an SH3 fold in solution. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:705-14. [DOI: 10.1016/j.bbabio.2016.03.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/02/2016] [Accepted: 03/23/2016] [Indexed: 12/22/2022]
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Zhang Y, Ding Y. Molecular dynamics simulation and bioinformatics study on chloroplast stromal ridge complex from rice (Oryza sativa L.). BMC Bioinformatics 2016; 17:28. [PMID: 26753869 PMCID: PMC4709881 DOI: 10.1186/s12859-016-0877-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 01/04/2016] [Indexed: 11/29/2022] Open
Abstract
Background Rice (Oryza sativa L.) is one of the most important cereal crops in the world and its yield is closely related to the photosynthesis efficiency. The chloroplast stromal ridge complex consisting of PsaC-PsaD-PsaE plays an important role in plant photosynthesis, which has been a subject of many studies. Till now, the recognition mechanism between PsaC and PsaD in rice is still not fully understood. Results Here, we present the interaction features of OsPsaC and OsPsaD by molecular dynamics simulations and bioinformatics. Firstly, we identified interacting residues in the OsPsaC-OsPsaD complex during simulations. Significantly, important hydrogen bonds were observed in residue pairs R19-E103, D47-K62, R53-E63, Y81-R20, Y81-R61 and L26-V105. Free energy calculations suggested two salt bridges R19-E103 and D47-K62 were essential to maintain the OsPsaC-OsPsaD interaction. Supportively, electrostatic potentials surfaces of OsPsaD exhibited electrostatic attraction helped to stabilize the residue pairs R19-E103 and D47-K62. In particular, the importance of R19 was further verified by two 500 ns CG-MD simulations. Secondly, this study compared the stromal ridge complex in rice with that in other organisms. Notably, alignments of amino acids showed these two salt bridges R19-E103 and D47-K62 also existed in other organisms. Electrostatic potentials surfaces and X-ray structural analysis strongly suggested the stromal ridge complex in other organisms adopted a similar and general recognition mechanism. Conclusions These results together provided structure basis and dynamics behavior to understand recognition and assembly of the stromal ridge complex in rice. Electronic supplementary material The online version of this article (doi:10.1186/s12859-016-0877-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yubo Zhang
- State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan, 430072, People's Republic of China.
| | - Yi Ding
- State Key Laboratory of Hybrid Rice, Department of Genetics, College of Life Sciences, Wuhan University, Wuhan, 430072, People's Republic of China.
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Gao L, Ge H, Huang X, Liu K, Zhang Y, Xu W, Wang Y. Systematically ranking the tightness of membrane association for peripheral membrane proteins (PMPs). Mol Cell Proteomics 2014; 14:340-53. [PMID: 25505158 DOI: 10.1074/mcp.m114.044800] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Large-scale quantitative evaluation of the tightness of membrane association for nontransmembrane proteins is important for identifying true peripheral membrane proteins with functional significance. Herein, we simultaneously ranked more than 1000 proteins of the photosynthetic model organism Synechocystis sp. PCC 6803 for their relative tightness of membrane association using a proteomic approach. Using multiple precisely ranked and experimentally verified peripheral subunits of photosynthetic protein complexes as the landmarks, we found that proteins involved in two-component signal transduction systems and transporters are overall tightly associated with the membranes, whereas the associations of ribosomal proteins are much weaker. Moreover, we found that hypothetical proteins containing the same domains generally have similar tightness. This work provided a global view of the structural organization of the membrane proteome with respect to divergent functions, and built the foundation for future investigation of the dynamic membrane proteome reorganization in response to different environmental or internal stimuli.
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Affiliation(s)
- Liyan Gao
- From the ‡State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China
| | - Haitao Ge
- §State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
| | - Xiahe Huang
- From the ‡State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China
| | - Kehui Liu
- From the ‡State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China
| | - Yuanya Zhang
- From the ‡State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China
| | - Wu Xu
- ¶Department of Chemistry, University of Louisiana at Lafayette, Lafayette, Louisiana 70504
| | - Yingchun Wang
- From the ‡State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No.1 West Beichen Rd., Beijing 100101, China;
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Electron-transfer kinetics in cyanobacterial cells: methyl viologen is a poor inhibitor of linear electron flow. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1847:212-222. [PMID: 25448535 DOI: 10.1016/j.bbabio.2014.10.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 10/24/2014] [Accepted: 10/28/2014] [Indexed: 01/13/2023]
Abstract
The inhibitor methyl viologen (MV) has been widely used in photosynthesis to study oxidative stress. Its effects on electron transfer kinetics in Synechocystis sp. PCC6803 cells were studied to characterize its electron-accepting properties. For the first hundreds of flashes following MV addition at submillimolar concentrations, the kinetics of NADPH formation were hardly modified (less than 15% decrease in signal amplitude) with a significant signal decrease only observed after more flashes or continuous illumination. The dependence of the P700 photooxidation kinetics on the MV concentration exhibited a saturation effect at 0.3 mM MV, a concentration which inhibits the recombination reactions in photosystem I. The kinetics of NADPH formation and decay under continuous light with MV at 0.3 mM showed that MV induces the oxidation of the NADP pool in darkness and that the yield of linear electron transfer decreased by only 50% after 1.5-2 photosystem-I turnovers. The unexpectedly poor efficiency of MV in inhibiting NADPH formation was corroborated by in vitro flash-induced absorption experiments with purified photosystem-I, ferredoxin and ferredoxin-NADP(+)-oxidoreductase. These experiments showed that the second-order rate constants of MV reduction are 20 to 40-fold smaller than the competing rate constants involved in reduction of ferredoxin and ferredoxin-NADP(+)-oxidoreductase. The present study shows that MV, which accepts electrons in vivo both at the level of photosystem-I and ferredoxin, can be used at submillimolar concentrations to inhibit recombination reactions in photosystem-I with only a moderate decrease in the efficiency of fast reactions involved in linear electron transfer and possibly cyclic electron transfer.
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9
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Yamamoto H, Shikanai T. In planta mutagenesis of Src homology 3 domain-like fold of NdhS, a ferredoxin-binding subunit of the chloroplast NADH dehydrogenase-like complex in Arabidopsis: a conserved Arg-193 plays a critical role in ferredoxin binding. J Biol Chem 2013; 288:36328-37. [PMID: 24225949 DOI: 10.1074/jbc.m113.511584] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Chloroplast NADH dehydrogenase-like (NDH) complex mediates cyclic electron transport around photosystem I and chlororespiration in angiosperms. The Src homology 3 domain (SH3)-like fold protein NdhS/CRR31 is an NDH subunit that is necessary for high affinity binding of ferredoxin, indicating that chloroplast NDH functions as a ferredoxin:plastoquinone oxidoreductase. However, the mechanism of the interaction between NdhS and ferredoxin is unclear. In this study, we analyzed their interaction in planta by using site-directed mutagenesis of NdhS. In general, binding of ferredoxin to its target proteins depends on electrostatic interaction. In silico analysis predicted the presence of a positively charged pocket in the SH3-like domain of NdhS, where nine charged residues are highly conserved among plants. Systematic alteration of these sites with neutral glutamine revealed that only arginine 193 was required for high NDH activity in vivo. Further replacement of arginine 193 with negatively charged aspartate or glutamate or hydrophobic alanine significantly decreased the efficiency of ferredoxin-dependent plastoquinone reduction by NDH in ruptured chloroplasts. Similar results were obtained in in vivo analyses of NDH activity and electron transport. From these results, we propose that the positive charge of arginine 193 in the SH3-like domain of NdhS is critical for electrostatic interaction with ferredoxin in vivo.
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Affiliation(s)
- Hiroshi Yamamoto
- From the Department of Botany, Graduate School of Science, Kyoto University, Kyoto 606-8502 and
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10
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Grimaud F, Renaut J, Dumont E, Sergeant K, Lucau-Danila A, Blervacq AS, Sellier H, Bahrman N, Lejeune-Hénaut I, Delbreil B, Goulas E. Exploring chloroplastic changes related to chilling and freezing tolerance during cold acclimation of pea (Pisum sativum L.). J Proteomics 2013; 80:145-59. [PMID: 23318888 DOI: 10.1016/j.jprot.2012.12.030] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 12/22/2012] [Accepted: 12/29/2012] [Indexed: 01/10/2023]
Abstract
Pea (Pisum sativum L.) productivity is linked to its ability to cope with abiotic stresses such as low temperatures during fall and winter. In this study, we investigate the chloroplast-related changes occurring during pea cold acclimation, in order to further lead to genetic improvement of its field performance. Champagne and Térèse, two pea lines with different acclimation capabilities, were studied by physiological measurements, sub-cellular fractionation followed by relative protein quantification and two-dimensional DIGE. The chilling tolerance might be related to an increase in protein related to soluble sugar synthesis, antioxidant potential, regulation of mRNA transcription and translation through the chloroplast. Freezing tolerance, only observed in Champagne, seems to rely on a higher inherent photosynthetic potential at the beginning of the cold exposure, combined with an early ability to start metabolic processes aimed at maintaining the photosynthetic capacity, optimizing the stoichiometry of the photosystems and inducing dynamic changes in carbohydrate and protein synthesis and/or turnover.
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Affiliation(s)
- Florent Grimaud
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France; Centre de Recherche Public, Gabriel Lippmann, Department of Environment and Agrobiotechnologies (EVA), 4422, Belvaux, Luxembourg.
| | - Jenny Renaut
- Centre de Recherche Public, Gabriel Lippmann, Department of Environment and Agrobiotechnologies (EVA), 4422, Belvaux, Luxembourg.
| | - Estelle Dumont
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
| | - Kjell Sergeant
- Centre de Recherche Public, Gabriel Lippmann, Department of Environment and Agrobiotechnologies (EVA), 4422, Belvaux, Luxembourg.
| | - Anca Lucau-Danila
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
| | - Anne-Sophie Blervacq
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
| | - Hélène Sellier
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
| | - Nasser Bahrman
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
| | - Isabelle Lejeune-Hénaut
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
| | - Bruno Delbreil
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
| | - Estelle Goulas
- Université Lille 1/INRA, UMR 1281, Stress Abiotiques et Différenciation des Végétaux cultivés, 59650 Villeneuve d'Ascq Cedex/Estrées-Mons, 80200 cedex, France.
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Dorrell RG, Howe CJ. What makes a chloroplast? Reconstructing the establishment of photosynthetic symbioses. J Cell Sci 2012; 125:1865-75. [PMID: 22547565 DOI: 10.1242/jcs.102285] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Earth is populated by an extraordinary diversity of photosynthetic eukaryotes. Many eukaryotic lineages contain chloroplasts, obtained through the endosymbiosis of a wide range of photosynthetic prokaryotes or eukaryotes, and a wide variety of otherwise non-photosynthetic species form transient associations with photosynthetic symbionts. Chloroplast lineages are likely to be derived from pre-existing transient symbioses, but it is as yet poorly understood what steps are required for the establishment of permanent chloroplasts from photosynthetic symbionts. In the past decade, several species that contain relatively recently acquired chloroplasts, such as the rhizarian Paulinella chromatophora, and non-photosynthetic taxa that maintain photosynthetic symbionts, such as the sacoglossan sea slug Elysia, the ciliate Myrionecta rubra and the dinoflagellate Dinophysis, have emerged as potential model organisms in the study of chloroplast establishment. In this Commentary, we compare recent molecular insights into the maintenance of chloroplasts and photosynthetic symbionts from these lineages, and others that might represent the early stages of chloroplast establishment. We emphasise the importance in the establishment of chloroplasts of gene transfer events that minimise oxidative stress acting on the symbiont. We conclude by assessing whether chloroplast establishment is facilitated in some lineages by a mosaic of genes, derived from multiple symbiotic associations, encoded in the host nucleus.
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Affiliation(s)
- Richard G Dorrell
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
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Jagannathan B, Shen G, Golbeck JH. The Evolution of Type I Reaction Centers: The Response to Oxygenic Photosynthesis. FUNCTIONAL GENOMICS AND EVOLUTION OF PHOTOSYNTHETIC SYSTEMS 2012. [DOI: 10.1007/978-94-007-1533-2_12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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13
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Mackiewicz P, Bodył A, Gagat P. Possible import routes of proteins into the cyanobacterial endosymbionts/plastids of Paulinella chromatophora. Theory Biosci 2011; 131:1-18. [PMID: 22209953 PMCID: PMC3334493 DOI: 10.1007/s12064-011-0147-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 12/13/2011] [Indexed: 01/13/2023]
Abstract
The rhizarian amoeba Paulinella chromatophora harbors two photosynthetically active and deeply integrated cyanobacterial endosymbionts acquired ~60 million years ago. Recent genomic analyses of P. chromatophora have revealed the loss of many essential genes from the endosymbiont's genome, and have identified more than 30 genes that have been transferred to the host cell's nucleus through endosymbiotic gene transfer (EGT). This indicates that, similar to classical primary plastids, Paulinella endosymbionts have evolved a transport system to import their nuclear-encoded proteins. To deduce how these proteins are transported, we searched for potential targeting signals in genes for 10 EGT-derived proteins. Our analyses indicate that five proteins carry potential signal peptides, implying they are targeted via the host endomembrane system. One sequence encodes a mitochondrial-like transit peptide, which suggests an import pathway involving a channel protein residing in the outer membrane of the endosymbiont. No N-terminal targeting signals were identified in the four other genes, but their encoded proteins could utilize non-classical targeting signals contained internally or in C-terminal regions. Several amino acids more often found in the Paulinella EGT-derived proteins than in their ancestral set (proteins still encoded in the endosymbiont genome) could constitute such signals. Characteristic features of the EGT-derived proteins are low molecular weight and nearly neutral charge, which both could be adaptations to enhance passage through the peptidoglycan wall present in the intermembrane space of the endosymbiont's envelope. Our results suggest that Paulinella endosymbionts/plastids have evolved several different import routes, as has been shown in classical primary plastids.
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Affiliation(s)
- Paweł Mackiewicz
- Department of Genomics, Faculty of Biotechnology, University of Wrocław, ul. Przybyszewskiego 63/77, 51-148 Wrocław, Poland.
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Yamamoto H, Peng L, Fukao Y, Shikanai T. An Src homology 3 domain-like fold protein forms a ferredoxin binding site for the chloroplast NADH dehydrogenase-like complex in Arabidopsis. THE PLANT CELL 2011; 23:1480-93. [PMID: 21505067 PMCID: PMC3101538 DOI: 10.1105/tpc.110.080291] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 03/07/2011] [Accepted: 04/05/2011] [Indexed: 05/18/2023]
Abstract
Some subunits of chloroplast NAD(P)H dehydrogenase (NDH) are related to those of the respiratory complex I, and NDH mediates photosystem I (PSI) cyclic electron flow. Despite extensive surveys, the electron donor and its binding subunits have not been identified. Here, we identified three novel components required for NDH activity. CRRJ and CRRL are J- and J-like proteins, respectively, and are components of NDH subcomplex A. CRR31 is an Src homology 3 domain-like fold protein, and its C-terminal region may form a tertiary structure similar to that of PsaE, a ferredoxin (Fd) binding subunit of PSI, although the sequences are not conserved between CRR31 and PsaE. Although CRR31 can accumulate in thylakoids independently of NDH, its accumulation requires CRRJ, and CRRL accumulation depends on CRRJ and NDH. CRR31 was essential for the efficient operation of Fd-dependent plastoquinone reduction in vitro. The phenotype of crr31 pgr5 suggested that CRR31 is required for NDH activity in vivo. We propose that NDH functions as a PGR5-PGRL1 complex-independent Fd:plastoquinone oxidoreductase in chloroplasts and rename it the NADH dehydrogenase-like complex.
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Affiliation(s)
- Hiroshi Yamamoto
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Lianwei Peng
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yoichiro Fukao
- Plant Global Educational Project, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma 630-0101, Japan
| | - Toshiharu Shikanai
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
- Address correspondence to
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Busch A, Hippler M. The structure and function of eukaryotic photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1807:864-77. [PMID: 20920463 DOI: 10.1016/j.bbabio.2010.09.009] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 09/20/2010] [Accepted: 09/28/2010] [Indexed: 12/27/2022]
Abstract
Eukaryotic photosystem I consists of two functional moieties: the photosystem I core, harboring the components for the light-driven charge separation and the subsequent electron transfer, and the peripheral light-harvesting complex (LHCI). While the photosystem I-core remained highly conserved throughout the evolution, with the exception of the oxidizing side of photosystem I, the LHCI complex shows a high degree of variability in size, subunits composition and bound pigments, which is due to the large variety of different habitats photosynthetic organisms dwell in. Besides summarizing the most current knowledge on the photosystem I-core structure, we will discuss the composition and structure of the LHCI complex from different eukaryotic organisms, both from the red and the green clade. Furthermore, mechanistic insights into electron transfer between the donor and acceptor side of photosystem I and its soluble electron transfer carrier proteins will be given. This article is part of a Special Issue entitled: Regulation of Electron Transport in Chloroplasts.
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Affiliation(s)
- Andreas Busch
- Department of Plant Biology and Biotechnology, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
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16
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Nowack ECM, Vogel H, Groth M, Grossman AR, Melkonian M, Glockner G. Endosymbiotic Gene Transfer and Transcriptional Regulation of Transferred Genes in Paulinella chromatophora. Mol Biol Evol 2010; 28:407-22. [DOI: 10.1093/molbev/msq209] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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17
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Jagannathan B, Dekat S, Golbeck JH, Lakshmi KV. The Assembly of a Multisubunit Photosynthetic Membrane Protein Complex: A Site-Specific Spin Labeling EPR Spectroscopic Study of the PsaC Subunit in Photosystem I. Biochemistry 2010; 49:2398-408. [DOI: 10.1021/bi901483f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Sarah Dekat
- Department of Chemistry and Chemical Biology and The Baruch ’60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, New York 12180
| | - John H. Golbeck
- Department of Biochemistry and Molecular Biology
- Department of Chemistry
| | - K. V. Lakshmi
- Department of Chemistry and Chemical Biology and The Baruch ’60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, New York 12180
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18
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Medina M. Structural and mechanistic aspects of flavoproteins: photosynthetic electron transfer from photosystem I to NADP+. FEBS J 2009; 276:3942-58. [PMID: 19583765 DOI: 10.1111/j.1742-4658.2009.07122.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This minireview covers the research carried out in recent years into different aspects of the function of the flavoproteins involved in cyanobacterial photosynthetic electron transfer from photosystem I to NADP(+), flavodoxin and ferredoxin-NADP(+) reductase. Interactions that stabilize protein-flavin complexes and tailor the midpoint potentials in these proteins, as well as many details of the binding and electron transfer to protein and ligand partners, have been revealed. In addition to their role in photosynthesis, flavodoxin and ferredoxin-NADP(+) reductase are ubiquitous flavoenzymes that deliver NAD(P)H or low midpoint potential one-electron donors to redox-based metabolisms in plastids, mitochondria and bacteria. They are also the basic prototypes for a large family of diflavin electron transferases with common functional and structural properties. Understanding their mechanisms should enable greater comprehension of the many physiological roles played by flavodoxin and ferredoxin-NADP(+) reductase, either free or as modules in multidomain proteins. Many aspects of their biochemistry have been extensively characterized using a combination of site-directed mutagenesis, steady-state and transient kinetics, spectroscopy and X-ray crystallography. Despite these considerable advances, various key features of the structural-function relationship are yet to be explained in molecular terms. Better knowledge of these systems and their particular properties may allow us to envisage several interesting applications of these proteins beyond their physiological functions.
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Affiliation(s)
- Milagros Medina
- Departamento de Bioquímica y Biología Molecular y Celular and BFIF, Universidad de Zaragoza, Spain.
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19
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Jeanjean R, Latifi A, Matthijs HC, Havaux M. The PsaE subunit of photosystem I prevents light-induced formation of reduced oxygen species in the cyanobacterium Synechocystis sp. PCC 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1777:308-16. [DOI: 10.1016/j.bbabio.2007.11.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 11/28/2007] [Accepted: 11/28/2007] [Indexed: 11/25/2022]
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20
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Cassan N, Lagoutte B, Sétif P. Ferredoxin-NADP+ reductase. Kinetics of electron transfer, transient intermediates, and catalytic activities studied by flash-absorption spectroscopy with isolated photosystem I and ferredoxin. J Biol Chem 2005; 280:25960-72. [PMID: 15894798 DOI: 10.1074/jbc.m503742200] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The electron transfer cascade from photosystem I to NADP+ was studied at physiological pH by flash-absorption spectroscopy in a Synechocystis PCC6803 reconstituted system comprised of purified photosystem I, ferredoxin, and ferredoxin-NADP+ reductase. Experiments were conducted with a 34-kDa ferredoxin-NADP+ reductase homologous to the chloroplast enzyme and a 38-kDa N-terminal extended form. Small differences in kinetic and catalytic properties were found for these two forms, although the largest one has a 3-fold decreased affinity for ferredoxin. The dissociation rate of reduced ferredoxin from photosystem I (800 s(-1)) and the redox potential of the first reduction of ferredoxin-NADP+ reductase (-380 mV) were determined. In the absence of NADP+, differential absorption spectra support the existence of a high affinity complex between oxidized ferredoxin and semireduced ferredoxin-NADP+ reductase. An effective rate of 140-170 s(-1) was also measured for the second reduction of ferredoxin-NADP+ reductase, this process having a rate constant similar to that of the first reduction. In the presence of NADP+, the second-order rate constant for the first reduction of ferredoxin-NADP+ reductase was 20% slower than in its absence, in line with the existence of ternary complexes (ferredoxin-NADP+ reductase)-NADP+-ferredoxin. A single catalytic turnover was monitored, with 50% NADP+ being reduced in 8-10 ms using 1.6 microM photosystem I. In conditions of multiple turnover, we determined initial rates of 360-410 electrons per s and per ferredox-in-NADP+ reductase for the reoxidation of 3.5 microM photoreduced ferredoxin. Identical rates were found with photosystem I lacking the PsaE subunit and wild type photosystem I. This suggests that, in contrast with previous proposals, the PsaE subunit is not involved in NADP+ photoreduction.
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Affiliation(s)
- Nicolas Cassan
- Service de Bioénergétique and CNRS URA 2096, Département de Biologie Joliot Curie, CEA Saclay, 91191 Gif sur Yvette, France
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21
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Kanervo E, Suorsa M, Aro EM. Functional flexibility and acclimation of the thylakoid membrane. Photochem Photobiol Sci 2005; 4:1072-80. [PMID: 16307125 DOI: 10.1039/b507866k] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Light is an elusive substrate for the function of photosynthetic light reactions of photosynthesis in the thylakoid membrane. Therefore structural and functional dynamics, which occur in the timescale from seconds to several days, are required both at low and high light conditions. The best characterized short-time regulation mechanism at low light is a rapid state transition, resulting in higher absorption cross section of PSI at the expense of PSII. If the low light conditions continue, activation of the lhcb-genes and synthesis of the light-harvesting proteins will occur to optimize the functions of PSII and PSI. At high light, the transition to state 2 is completely inhibited, but the feedback de-excitation of absorbed energy as heat, known as the energy-dependent quenching (q(E)), is rapidly set up. It requires, at least, the DeltapH-dependent activation of violaxanthin de-epoxidase and involvement of the PsbS protein. Another crucial mechanism for protection against the high light stress is the PSII repair cycle. Furthermore, the water-water cycle, cyclic electron transfer around PSI and chlororespiration are important means induced under high irradiation, functioning mainly to avoid an excess production of reactive oxygen species.
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Affiliation(s)
- Eira Kanervo
- Department of Biology, University of Turku, FIN-20014, Turku, Finland
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22
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Grotjohann I, Fromme P. Structure of cyanobacterial photosystem I. PHOTOSYNTHESIS RESEARCH 2005; 85:51-72. [PMID: 15977059 DOI: 10.1007/s11120-005-1440-4] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2004] [Accepted: 01/28/2005] [Indexed: 05/03/2023]
Abstract
Photosystem I is one of the most fascinating membrane protein complexes for which a structure has been determined. It functions as a bio-solar energy converter, catalyzing one of the first steps of oxygenic photosynthesis. It captures the light of the sun by means of a large antenna system, consisting of chlorophylls and carotenoids, and transfers the energy to the center of the complex, driving the transmembrane electron transfer from plastoquinone to ferredoxin. Cyanobacterial Photosystem I is a trimer consisting of 36 proteins to which 381 cofactors are non-covalently attached. This review discusses the complex function of Photosystem I based on the structure of the complex at 2.5 A resolution as well as spectroscopic and biochemical data.
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Xu W, Tang H, Wang Y, Chitnis PR. Proteins of the cyanobacterial photosystem I. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1507:32-40. [PMID: 11687206 DOI: 10.1016/s0005-2728(01)00208-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyanobacterial photosystem (PS) I is remarkably similar to its counterpart in the chloroplast of plants and algae. Therefore, it has served as a prototype for the type I reaction centers of photosynthesis. Cyanobacterial PS I contains 11-12 proteins. Some of the cyanobacterial proteins are modified post-translationally. Reverse genetics has been used to generate subunit-deficient cyanobacterial mutants, phenotypes of which have revealed the functions of the missing proteins. The cyanobacterial PS I proteins bind cofactors, provide docking sites for electron transfer proteins, participate in tertiary and quaternary organization of the complex and protect the electron transfer centers. Many of these mutants are now being used in sophisticated structure-function analyses. Yet, the roles of some proteins of the cyanobacterial PS I are unknown. It is necessary to examine functions of these proteins on a global scale of cell physiology, biogenesis and evolution.
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Affiliation(s)
- W Xu
- Department of Biochemistry, Biophysics and Molecular Biology, 4156 Molecular Biology Building, Iowa State University, Ames, IA 50011, USA
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24
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Abstract
Ferredoxin and flavodoxin are soluble proteins which are reduced by the terminal electron acceptors of photosystem I. The kinetics of ferredoxin (flavodoxin) photoreduction are discussed in detail, together with the last steps of intramolecular photosystem I electron transfer which precede ferredoxin (flavodoxin) reduction. The present knowledge concerning the photosystem I docking site for ferredoxin and flavodoxin is described in the second part of the review.
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Affiliation(s)
- P Sétif
- Section de Bioénergétique and CNRS URA 2096, Département de Biologie Cellulaire et Moléculaire, CEA Saclay, 91191, Gif sur Yvette, France.
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25
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Baymann F, Brugna M, Mühlenhoff U, Nitschke W. Daddy, where did (PS)I come from? BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1507:291-310. [PMID: 11687221 DOI: 10.1016/s0005-2728(01)00209-2] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The reacton centre I (RCI)-type photosystems from plants, cyano-, helio- and green sulphur bacteria are compared and the essential properties of an archetypal RCI are deduced. Species containing RCI-type photosystems most probably cluster together on a common branch of the phylogenetic tree. The predicted branching order is green sulphur, helio- and cyanobacteria. Striking similarities between RCI- and RCII-type photosystems recently became apparent in the three-dimensional structures of photosystem I (PSI), PSII and RCII. The phylogenetic relationship between all presently known photosystems is analysed suggesting (a) RCI as the ancestral photosystem and (b) the descendence of PSII from RCI via gene duplication and gene splitting. An evolutionary model trying to rationalise available data is presented.
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Affiliation(s)
- F Baymann
- Laboratoire de Bioénergétique et Ingénierie des Protéines, Institut de Biologie Structurale et Microbiologie, Marseille, France
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26
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Abstract
In plants and cyanobacteria, the primary step in oxygenic photosynthesis, the light induced charge separation, is driven by two large membrane intrinsic protein complexes, the photosystems I and II. Photosystem I catalyses the light driven electron transfer from plastocyanin/cytochrome c(6) on the lumenal side of the membrane to ferredoxin/flavodoxin at the stromal side by a chain of electron carriers. Photosystem I of Synechococcus elongatus consists of 12 protein subunits, 96 chlorophyll a molecules, 22 carotenoids, three [4Fe4S] clusters and two phylloquinones. Furthermore, it has been discovered that four lipids are intrinsic components of photosystem I. Photosystem I exists as a trimer in the native membrane with a molecular mass of 1068 kDa for the whole complex. The X-ray structure of photosystem I at a resolution of 2.5 A shows the location of the individual subunits and cofactors and provides new information on the protein-cofactor interactions. [P. Jordan, P. Fromme, H.T. Witt, O. Klukas, W. Saenger, N. Krauss, Nature 411 (2001) 909-917]. In this review, biochemical data and results of biophysical investigations are discussed with respect to the X-ray crystallographic structure in order to give an overview of the structure and function of this large membrane protein.
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Affiliation(s)
- P Fromme
- Max Volmer Laboratorium für Biophysikalische Chemie Institut für Chemie, Technische Universität Berlin, Germany.
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27
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Bottin H, Hanley J, Lagoutte B. Role of acidic amino acid residues of PsaD subunit on limiting the affinity of photosystem I for ferredoxin. Biochem Biophys Res Commun 2001; 287:833-6. [PMID: 11573938 DOI: 10.1006/bbrc.2001.5658] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The PsaD subunit of photosystem I is one of the central polypeptides for the interaction with ferredoxin, its acidic electron acceptor. In the cyanobacterium Synechocystis 6803, this role is partly performed by a sequence extending approximately from histidine 97 to arginine 119, close to the C-terminus. In the present work, acidic amino acids D100, E105, and E109 are shown to moderate the affinity of Photosystem I for ferredoxin. Most single replacements of these residues by neutral amino acids increased the affinity for ferredoxin, resulting in a dissociation constant as low as 0.015 microM for the E105Q mutant (wild-type K(D) = 0.4 microM). This is the first report on the limitation of photosystem I affinity for ferredoxin due to acidic amino acids from PsaD subunit. It highlights the occurrence of a negative control on the binding during the formation of transient complexes between electron carriers.
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Affiliation(s)
- H Bottin
- Département de Biologie Cellulaire et Moléculaire, Service de Bioénergétique, CEA, CNRS URA 2096, CE de Saclay, 91191 Gif sur Yvette Cedex, France.
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28
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Chitnis PR. PHOTOSYSTEM I: Function and Physiology. ANNUAL REVIEW OF PLANT PHYSIOLOGY AND PLANT MOLECULAR BIOLOGY 2001; 52:593-626. [PMID: 11337410 DOI: 10.1146/annurev.arplant.52.1.593] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Photosystem I is the light-driven plastocyanin-ferredoxin oxidoreductase in the thylakoid membranes of cyanobacteria and chloroplasts. In recent years, sophisticated spectroscopy, molecular genetics, and biochemistry have been used to understand the light conversion and electron transport functions of photosystem I. The light-harvesting complexes and internal antenna of photosystem I absorb photons and transfer the excitation energy to P700, the primary electron donor. The subsequent charge separation and electron transport leads to the reduction of ferredoxin. The photosystem I proteins are responsible for the precise arrangement of cofactors and determine redox properties of the electron transfer centers. With the availability of genomic information and the structure of photosystem I, one can now probe the functions of photosystem I proteins and cofactors. The strong reductant produced by photosystem I has a central role in chloroplast metabolism, and thus photosystem I has a critical role in the metabolic networks and physiological responses in plants.
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Affiliation(s)
- Parag R Chitnis
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011; e-mail:
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29
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Lagoutte B, Hanley J, Bottin H. Multiple functions for the C terminus of the PsaD subunit in the cyanobacterial photosystem I complex. PLANT PHYSIOLOGY 2001; 126:307-316. [PMID: 11351094 PMCID: PMC102305 DOI: 10.1104/pp.126.1.307] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2001] [Revised: 01/16/2001] [Accepted: 02/13/2001] [Indexed: 05/23/2023]
Abstract
PsaD subunit of Synechocystis sp PCC 6803 photosystem I (PSI) plays a critical role in the stability of the complex and is part of the docking site for ferredoxin (Fd). In the present study we describe major physiological and biochemical effects resulting from mutations in the accessible C-terminal end of the protein. Four basic residues were mutated: R111, K117, K131, and K135, and a large 36-amino acid deletion was generated at the C terminus. PSI from R111C mutant has a 5-fold decreased affinity for Fd, comparable with the effect of the C terminus deletion, and NADP+ is photoreduced with a 2-fold decreased rate, without consequence on cell growth. The K117A mutation has no effect on the affinity for Fd, but decreases the stability of PsaE subunit, a loss of stability also observed in R111C and the deletion mutants. The double mutation K131A/K135A does not change Fd binding and reduction, but decreases the overall stability of PSI and impairs the cell growth at temperatures above 30 degrees C. Three mutants, R111C, K117A, and the C-terminal deleted exhibit a higher content of the trimeric form of PSI, in apparent relation to the removal of solvent accessible positive charges. Various regions in the C terminus of cyanobacterial PsaD thus are involved in Fd strong binding, PSI stability, and accumulation of trimeric PSI.
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Affiliation(s)
- B Lagoutte
- Département de Biologie Cellulaire et Moléculaire, Service de Bioénergétique, and Centre National de la Recherche Scientifique Unité de Recherche Associée 2096, CE de Saclay, 91191 Gif sur Yvette cedex, France.
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30
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Metzler DE, Metzler CM, Sauke DJ. Light and Life. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50026-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Morales R, Charon MH, Kachalova G, Serre L, Medina M, Gómez-Moreno C, Frey M. A redox-dependent interaction between two electron-transfer partners involved in photosynthesis. EMBO Rep 2000; 1:271-6. [PMID: 11256611 PMCID: PMC1083731 DOI: 10.1093/embo-reports/kvd057] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ferredoxin:NADP+:reductase (FNR) catalyzes one terminal step of the conversion of light energy into chemical energy during photosynthesis. FNR uses two high energy electrons photoproduced by photosystem I (PSI) and conveyed, one by one, by a ferredoxin (Fd), to reduce NADP+ to NADPH. The reducing power of NADPH is finally involved in carbon assimilation. The interaction between oxidized FNR and Fd was studied by crystallography at 2.4 A resolution leading to a three-dimensional picture of an Fd-FNR biologically relevant complex. This complex suggests that FNR and Fd specifically interact prior to each electron transfer and disassemble upon a redox-linked conformational change of the Fd.
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Affiliation(s)
- R Morales
- LCCP, Institut de Biologie Structurale J.P. Ebel, CEA-CNRS, Grenoble, France
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32
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Guillouard I, Lagoutte B, Moal G, Bottin H. Importance of the region including aspartates 57 and 60 of ferredoxin on the electron transfer complex with photosystem I in the cyanobacterium Synechocystis sp. PCC 6803. Biochem Biophys Res Commun 2000; 271:647-53. [PMID: 10814516 DOI: 10.1006/bbrc.2000.2687] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ferredoxin reduction by photosystem I has been studied by flash-absorption spectroscopy. Aspartate residues 20, 57, and 60 of ferredoxin were changed to alanine, cysteine, arginine, or lysine. On the one hand, electron transfer from photosystem I to all mutated ferredoxins still occurs on a microsecond time scale, with half-times of ferredoxin reduction mostly conserved compared to wild-type ferredoxin. On the other hand, the total amplitude of the fast first-order reduction varies largely when residues 57 or 60 are modified, in apparent relation to the charge modification (neutralized or inverted). Substituting these two residues for lysine or arginine induce strong effects on ferredoxin binding (up to sixfold increase in K(D)), whereas the same substitution on aspartate 20, a spatially related residue, results in moderate effects (maximum twofold increase in K(D)). In addition, double mutations to arginine or lysine were performed on both aspartates 57 and 60. The mutated proteins have a 15- to 20-fold increased K(D) and show strong modifications in the amplitudes of the fast reduction kinetics. These results indicate that the acidic area of ferredoxin including aspartates 57 and 60, located opposite to the C-terminus, is crucial for high affinity interactions with photosystem I.
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Affiliation(s)
- I Guillouard
- CEA, Département de Biologie Cellulaire et Moléculaire, Section de Bioénergétique, CNRS URA 2096, CE de Saclay, Gif sur Yvette Cedex, 91191, France
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Barth P, Guillouard I, Sétif P, Lagoutte B. Essential role of a single arginine of photosystem I in stabilizing the electron transfer complex with ferredoxin. J Biol Chem 2000; 275:7030-6. [PMID: 10702267 DOI: 10.1074/jbc.275.10.7030] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PsaE is one of the photosystem I subunits involved in ferredoxin binding. The central role of arginine 39 of this 8-kDa peripheral polypeptide has been established by a series of mutations. The neutral substitution R39Q leads to a 250-fold increase of the dissociation constant K(d) of the photosystem I-ferredoxin complex, as large as the increase induced by PsaE deletion. At pH 8.0, this K(d) value strongly depends on the charge of the residue substituting Arg-39: 0.22 microM for wild type, 1.5 microM for R39K, 56 microM for R39Q, and more than 100 microM for R39D. The consequences of arginine 39 substitution for the titratable histidine were analyzed as a function of pH. The K(d) value of R39H is increased 140 times at pH 8.0 but only 5 times at pH 5.8, which is assigned to the protonation of histidine at low pH. In the mutant R39Q, the association rate of ferredoxin was decreased 3-fold compared with wild type, whereas an 80-fold increase is calculated for the dissociation rate. We propose that a major contribution of PsaE is to provide a prominent positive charge at position 39 for controlling the electrostatic interaction and lifetime of the complex with ferredoxin.
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Affiliation(s)
- P Barth
- CEA, Département de Biologie Cellulaire et Moléculaire, Section de Bioénergétique and CNRS URA 2096, C.E. Saclay, 91191 Gif sur Yvette, France
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Fischer N, Sétif P, Rochaix JD. Site-directed mutagenesis of the PsaC subunit of photosystem I. F(b) is the cluster interacting with soluble ferredoxin. J Biol Chem 1999; 274:23333-40. [PMID: 10438510 DOI: 10.1074/jbc.274.33.23333] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The two [4Fe-4S] clusters F(A) and F(B) are the terminal electron acceptors of photosystem I (PSI) that are bound by the stromal subunit PsaC. Soluble ferredoxin (Fd) binds to PSI via electrostatic interactions and is reduced by the outermost iron-sulfur cluster of PsaC. We have generated six site-directed mutants of the green alga Chlamydomonas reinhardtii in which residues located close to the iron-sulfur clusters of PsaC are changed. The acidic residues Asp(9) and Glu(46), which are located one residue upstream of the first cysteine liganding cluster F(B) and F(A), respectively, were changed to a neutral or a basic amino acid. Although Fd reduction is not affected by the E46Q and E46K mutations, a slight increase of Fd affinity (from 1.3- to 2-fold) was observed by flash absorption spectroscopy for the D9N and D9K mutant PSI complexes. In the FA(2) triple mutant (V49I/K52T/R53Q), modification of residues located next to the F(A) cluster leads to partial destabilization of the PSI complex. The electron paramagnetic resonance properties of cluster F(A) are affected, and a 3-fold decrease of Fd affinity is observed. The introduction of positively charged residues close to the F(B) cluster in the FB(1) triple mutant (I12V/T15K/Q16R) results in a 60-fold increase of Fd affinity as measured by flash absorption spectroscopy and a larger amount of PsaC-Fd cross-linking product. The first-order kinetics are similar to wild type kinetics (two phases with t((1)/(2)) of <1 and approximately 4.5 microseconds) for all mutants except FB(1), where Fd reduction is almost monophasic with t((1)/(2)) < 1 microseconds. These data indicate that F(B) is the cluster interacting with Fd and therefore the outermost iron-sulfur cluster of PSI.
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Affiliation(s)
- N Fischer
- Departments of Molecular Biology and Plant Biology, University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva, Switzerland
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