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Hussein R, Graça A, Forsman J, Aydin AO, Hall M, Gaetcke J, Chernev P, Wendler P, Dobbek H, Messinger J, Zouni A, Schröder WP. Cryo-electron microscopy reveals hydrogen positions and water networks in photosystem II. Science 2024; 384:1349-1355. [PMID: 38900892 DOI: 10.1126/science.adn6541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/16/2024] [Indexed: 06/22/2024]
Abstract
Photosystem II starts the photosynthetic electron transport chain that converts solar energy into chemical energy and thus sustains life on Earth. It catalyzes two chemical reactions: water oxidation to molecular oxygen and plastoquinone reduction. Coupling of electron and proton transfer is crucial for efficiency; however, the molecular basis of these processes remains speculative owing to uncertain water binding sites and the lack of experimentally determined hydrogen positions. We thus collected high-resolution cryo-electron microscopy data of fully hydrated photosystem II from the thermophilic cyanobacterium Thermosynechococcus vestitus to a final resolution of 1.71 angstroms. The structure reveals several previously undetected partially occupied water binding sites and more than half of the hydrogen and proton positions. This clarifies the pathways of substrate water binding and plastoquinone B protonation.
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Affiliation(s)
- Rana Hussein
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - André Graça
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
| | - Jack Forsman
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
| | - A Orkun Aydin
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
| | - Michael Hall
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
| | - Julia Gaetcke
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - Petko Chernev
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
| | - Petra Wendler
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, Karl-Liebknecht Strasse 24-25, D 14476, Potsdam-Golm, Germany
| | - Holger Dobbek
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - Johannes Messinger
- Molecular Biomimetics, Department of Chemistry- Ångström Laboratory, Uppsala University, SE 75120 Uppsala, Sweden
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Sweden
| | - Athina Zouni
- Humboldt-Universität zu Berlin, Department of Biology, D 10099 Berlin, Germany
| | - Wolfgang P Schröder
- Department of Chemistry, Umeå University, SE 90187 Umeå, Sweden
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Sweden
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2
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Shevela D, Kern JF, Govindjee G, Messinger J. Solar energy conversion by photosystem II: principles and structures. PHOTOSYNTHESIS RESEARCH 2023; 156:279-307. [PMID: 36826741 PMCID: PMC10203033 DOI: 10.1007/s11120-022-00991-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/01/2022] [Indexed: 05/23/2023]
Abstract
Photosynthetic water oxidation by Photosystem II (PSII) is a fascinating process because it sustains life on Earth and serves as a blue print for scalable synthetic catalysts required for renewable energy applications. The biophysical, computational, and structural description of this process, which started more than 50 years ago, has made tremendous progress over the past two decades, with its high-resolution crystal structures being available not only of the dark-stable state of PSII, but of all the semi-stable reaction intermediates and even some transient states. Here, we summarize the current knowledge on PSII with emphasis on the basic principles that govern the conversion of light energy to chemical energy in PSII, as well as on the illustration of the molecular structures that enable these reactions. The important remaining questions regarding the mechanism of biological water oxidation are highlighted, and one possible pathway for this fundamental reaction is described at a molecular level.
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Affiliation(s)
- Dmitry Shevela
- Department of Chemistry, Chemical Biological Centre, Umeå University, 90187, Umeå, Sweden.
| | - Jan F Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Govindjee Govindjee
- Department of Plant Biology, Department of Biochemistry and Center of Biophysics & Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Johannes Messinger
- Department of Chemistry, Chemical Biological Centre, Umeå University, 90187, Umeå, Sweden.
- Molecular Biomimetics, Department of Chemistry - Ångström, Uppsala University, 75120, Uppsala, Sweden.
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3
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Zhang C, Zhang G, Jin J, Zheng H, Zhou Z, Zhang S. Selenite-Catalyzed Reaction between Benzoquinone and Acetylacetone Deciphered the Enhanced Inhibition on Microcystis aeruginosa Growth. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:6188-6195. [PMID: 37011377 DOI: 10.1021/acs.est.2c09682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The coexistence of selenite (Se(IV)) and acetylacetone (AA) generated a synergistic effect on the growth inhibition of a bloom-forming cyanobacterium, Microcystis aeruginosa. The mechanism behind this phenomenon is of great significance in the control of harmful algal blooms. To elucidate the role of Se(IV) in this effect, the reactions in ternary solutions composed of Se(IV), AA (or two other similar hydrogen donors), and quinones, especially benzoquinone (BQ), were investigated. The transformation kinetic results demonstrate that Se(IV) played a catalytic role in the reactions between AA (or ascorbic acid) and quinones. By comparison with five other oxyanions (sulfite, sulfate, nitrite, nitrate, and phosphate) and two AA derivatives, the formation of an AA-Se(IV) complexation intermediate was confirmed as a key step in the accelerated reactions between BQ and AA. To our knowledge, this is the first report on Se(IV) as a catalyst for quinone-involved reactions. Since both quinones and Se are essential in cells and there are many other chemicals of similar electron-donating properties to that of AA, the finding here shed light on the regulation of electron transport chains in a variety of processes, especially the redox balances that are tuned by quinones and glutathione.
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Affiliation(s)
- Chengyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Guoyang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Jiyuan Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Hongcen Zheng
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Zhiwei Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing 210023, China
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Yilimulati M, Zhou L, Shevela D, Zhang S. Acetylacetone Interferes with Carbon and Nitrogen Metabolism of Microcystis aeruginosa by Cutting Off the Electron Flow to Ferredoxin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:9683-9692. [PMID: 35696645 DOI: 10.1021/acs.est.2c00776] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The regulation of photosynthetic machinery with a nonoxidative approach is a powerful but challenging strategy for the selective inhibition of bloom-forming cyanobacteria. Acetylacetone (AA) was recently found to be a target-selective cyanocide for Microcystis aeruginosa, but the cause and effect in the studied system are still unclear. By recording of the chemical fingerprints of the cells at two treatment intervals (12 and 72 h with 0.1 mM AA) with omics assays, the molecular mechanism of AA in inactivating Microcystis aeruginosa was elucidated. The results clearly reveal the effect of AA on ferredoxin and the consequent effects on the physiological and biochemical processes of Microcystis aeruginosa. In addition to its role as an electron acceptor of photosystem I, ferredoxin plays pivotal roles in the assimilation of nitrogen in cyanobacterial cells. The effect of AA on ferredoxin and on nonheme iron of photosystem II first cut off the photosynthetic electron transfer flow and then interrupted the synthesis of adenosine triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH), which ultimately might affect carbon fixation and nitrogen assimilation metabolisms. The results here provide missing pieces in the current knowledge on the selective inhibition of cyanobacteria, which should shed light on the better control of harmful blooms.
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Affiliation(s)
- Mihebai Yilimulati
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China
| | - Lang Zhou
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China
| | - Dmitry Shevela
- Department of Chemistry, Chemical Biological Centre, Umeå University, 90187 Umeå, Sweden
| | - Shujuan Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China
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5
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Robson TM, Aphalo PJ, Banaś AK, Barnes PW, Brelsford CC, Jenkins GI, Kotilainen TK, Łabuz J, Martínez-Abaigar J, Morales LO, Neugart S, Pieristè M, Rai N, Vandenbussche F, Jansen MAK. A perspective on ecologically relevant plant-UV research and its practical application. Photochem Photobiol Sci 2019; 18:970-988. [PMID: 30720036 DOI: 10.1039/c8pp00526e] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Plants perceive ultraviolet-B (UV-B) radiation through the UV-B photoreceptor UV RESISTANCE LOCUS 8 (UVR8), and initiate regulatory responses via associated signalling networks, gene expression and metabolic pathways. Various regulatory adaptations to UV-B radiation enable plants to harvest information about fluctuations in UV-B irradiance and spectral composition in natural environments, and to defend themselves against UV-B exposure. Given that UVR8 is present across plant organs and tissues, knowledge of the systemic signalling involved in its activation and function throughout the plant is important for understanding the context of specific responses. Fine-scale understanding of both UV-B irradiance and perception within tissues and cells requires improved application of knowledge about UV-attenuation in leaves and canopies, warranting greater consideration when designing experiments. In this context, reciprocal crosstalk among photoreceptor-induced pathways also needs to be considered, as this appears to produce particularly complex patterns of physiological and morphological response. Through crosstalk, plant responses to UV-B radiation go beyond simply UV-protection or amelioration of damage, but may give cross-protection over a suite of environmental stressors. Overall, there is emerging knowledge showing how information captured by UVR8 is used to regulate molecular and physiological processes, although understanding of upscaling to higher levels of organisation, i.e. organisms, canopies and communities remains poor. Achieving this will require further studies using model plant species beyond Arabidopsis, and that represent a broad range of functional types. More attention should also be given to plants in natural environments in all their complexity, as such studies are needed to acquire an improved understanding of the impact of climate change in the context of plant-UV responses. Furthermore, broadening the scope of experiments into the regulation of plant-UV responses will facilitate the application of UV radiation in commercial plant production. By considering the progress made in plant-UV research, this perspective highlights prescient topics in plant-UV photobiology where future research efforts can profitably be focussed. This perspective also emphasises burgeoning interdisciplinary links that will assist in understanding of UV-B effects across organisational scales and gaps in knowledge that need to be filled so as to achieve an integrated vision of plant responses to UV-radiation.
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Affiliation(s)
- T Matthew Robson
- Organismal and Evolutionary Biology, Viikki Plant Science Centre (ViPS), University of Helsinki, Finland.
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Herrmann AJ, Gehringer MM. An investigation into the effects of increasing salinity on photosynthesis in freshwater unicellular cyanobacteria during the late Archaean. GEOBIOLOGY 2019; 17:343-359. [PMID: 30874335 DOI: 10.1111/gbi.12339] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 02/04/2019] [Accepted: 02/10/2019] [Indexed: 06/09/2023]
Abstract
The oldest species of bacteria capable of oxygenic photosynthesis today are the freshwater Cyanobacteria Gloeobacter spp., belonging to the class Oxyphotobacteria. Several modern molecular evolutionary studies support the freshwater origin of cyanobacteria during the Archaean and their subsequent acquisition of salt tolerance mechanisms necessary for their expansion into the marine environment. This study investigated the effect of a sudden washout event from a freshwater location into either a brackish or marine environment on the photosynthetic efficiency of two unicellular freshwater cyanobacteria: the salt-tolerant Chroococcidiopsis thermalis PCC7203 and the cyanobacterial phylogenetic root species, Gloeobacter violaceus PCC7421. Strains were cultured under present atmospheric levels (PAL) of CO2 or an atmosphere containing elevated levels of CO2 and reduced O2 (eCO2 rO2 ) in simulated shallow water or terrestrial environmental conditions. Both strains exhibited a reduction in growth rates and gross photosynthesis, accompanied by significant reductions in chlorophyll a content, in brackish water, with only C. thermalis able to grow at marine salinity levels. While the experimental atmosphere caused a significant increase in gross photosynthesis rates in both strains, it did not increase their growth rates, nor the amount of O2 released. The differences in growth responses to increasing salinities could be attributed to genetic differences, with C. thermalis carrying additional genes for trehalose synthesis. This study demonstrates that, if cyanobacteria did evolve in a freshwater environment, they would have been capable of withstanding a sudden washout into increasingly saline environments. Both C. thermalis and G. violaceus continued to grow and photosynthesise, albeit at diminished rates, in brackish water, thereby providing a route for the evolution of open ocean-dwelling strains, necessary for the oxygenation of the Earth's atmosphere.
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Affiliation(s)
- Achim J Herrmann
- Department of Microbiology, Technical University of Kaiserslautern, Kaiserslautern, Germany
| | - Michelle M Gehringer
- Department of Microbiology, Technical University of Kaiserslautern, Kaiserslautern, Germany
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8
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Schirrmeister BE, Gugger M, Donoghue PCJ. Cyanobacteria and the Great Oxidation Event: evidence from genes and fossils. PALAEONTOLOGY 2015; 58:769-785. [PMID: 26924853 PMCID: PMC4755140 DOI: 10.1111/pala.12178] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 05/26/2015] [Indexed: 05/22/2023]
Abstract
Cyanobacteria are among the most ancient of evolutionary lineages, oxygenic photosynthesizers that may have originated before 3.0 Ga, as evidenced by free oxygen levels. Throughout the Precambrian, cyanobacteria were one of the most important drivers of biological innovations, strongly impacting early Earth's environments. At the end of the Archean Eon, they were responsible for the rapid oxygenation of Earth's atmosphere during an episode referred to as the Great Oxidation Event (GOE). However, little is known about the origin and diversity of early cyanobacterial taxa, due to: (1) the scarceness of Precambrian fossil deposits; (2) limited characteristics for the identification of taxa; and (3) the poor preservation of ancient microfossils. Previous studies based on 16S rRNA have suggested that the origin of multicellularity within cyanobacteria might have been associated with the GOE. However, single-gene analyses have limitations, particularly for deep branches. We reconstructed the evolutionary history of cyanobacteria using genome scale data and re-evaluated the Precambrian fossil record to get more precise calibrations for a relaxed clock analysis. For the phylogenomic reconstructions, we identified 756 conserved gene sequences in 65 cyanobacterial taxa, of which eight genomes have been sequenced in this study. Character state reconstructions based on maximum likelihood and Bayesian phylogenetic inference confirm previous findings, of an ancient multicellular cyanobacterial lineage ancestral to the majority of modern cyanobacteria. Relaxed clock analyses provide firm support for an origin of cyanobacteria in the Archean and a transition to multicellularity before the GOE. It is likely that multicellularity had a greater impact on cyanobacterial fitness and thus abundance, than previously assumed. Multicellularity, as a major evolutionary innovation, forming a novel unit for selection to act upon, may have served to overcome evolutionary constraints and enabled diversification of the variety of morphotypes seen in cyanobacteria today.
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Affiliation(s)
- Bettina E. Schirrmeister
- School of Earth SciencesUniversity of BristolLife Science Building24 Tyndall AvenueBristolBS8 1TQUK
| | - Muriel Gugger
- Institut PasteurCollection des Cyanobactéries75724Paris Cedex 15France
| | - Philip C. J. Donoghue
- School of Earth SciencesUniversity of BristolLife Science Building24 Tyndall AvenueBristolBS8 1TQUK
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Huang ZD, Masese T, Orikasa Y, Mori T, Yamamoto K. Vanadium phosphate as a promising high-voltage magnesium ion (de)-intercalation cathode host. RSC Adv 2015. [DOI: 10.1039/c4ra14416c] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electrochemically de-lithiated Li3V2(PO4)3, are investigated as high-voltage (∼3.0 V vs. Mg/Mg2+) cathode hosts for Mg2+ (de)-intercalation. The exceptional high voltage surpasses the hitherto reported values of cathodes for magnesium batteries.
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Affiliation(s)
- Zhen-Dong Huang
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM)
- National Synergistic Innovation Center for Advanced Materials (SICAM)
- Nanjing University of Posts & Telecommunications
- Nanjing 210023
- China
| | - Titus Masese
- Graduate School of Human and Environmental Studies
- Kyoto University
- Kyoto 606-8501
- Japan
| | - Yuki Orikasa
- Graduate School of Human and Environmental Studies
- Kyoto University
- Kyoto 606-8501
- Japan
| | - Takuya Mori
- Graduate School of Human and Environmental Studies
- Kyoto University
- Kyoto 606-8501
- Japan
| | - kentarou Yamamoto
- Graduate School of Human and Environmental Studies
- Kyoto University
- Kyoto 606-8501
- Japan
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Rajan ST, Nanda Kumar AK, Subramanian B. Nanocrystallization in magnetron sputtered Zr–Cu–Al–Ag thin film metallic glasses. CrystEngComm 2014. [DOI: 10.1039/c3ce42294a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Zr-based thin film metallic glasses (TFMG) were fabricated from a polycrystalline Zr48Cu36Al8Ag8 (at.%) target by DC magnetron sputtering. A series of characterization techniques were employed to study the structure, composition and thermal stability of the glassy coating. Annealing studies show nanocrystallites of CuZr2 in an amorphous matrix.
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Affiliation(s)
- S. Thanka Rajan
- Electrochemical Materials Science Division
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006, India
| | - A. K. Nanda Kumar
- Electrochemical Materials Science Division
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006, India
| | - B. Subramanian
- Electrochemical Materials Science Division
- CSIR-Central Electrochemical Research Institute
- Karaikudi 630 006, India
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