1
|
Masuda T, Mareš J, Shiozaki T, Inomura K, Fujiwara A, Prášil O. Crocosphaera watsonii - A widespread nitrogen-fixing unicellular marine cyanobacterium. JOURNAL OF PHYCOLOGY 2024; 60:604-620. [PMID: 38551849 DOI: 10.1111/jpy.13450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 12/14/2023] [Accepted: 02/08/2024] [Indexed: 06/12/2024]
Abstract
Crocosphaera watsonii is a unicellular N2-fixing (diazotrophic) cyanobacterium observed in tropical and subtropical oligotrophic oceans. As a diazotroph, it can be a source of bioavailable nitrogen (N) to the microbial community in N-limited environments, and this may fuel primary production in the regions where it occurs. Crocosphaera watsonii has been the subject of intense study, both in culture and in field populations. Here, we summarize the current understanding of the phylogenetic and physiological diversity of C. watsonii, its distribution, and its ecological niche. Analysis of the relationships among the individual Crocosphaera species and related free-living and symbiotic lineages of diazotrophs based on the nifH gene have shown that the C. watsonii group holds a basal position and that its sequence is more similar to Rippkaea and Zehria than to other Crocosphaera species. This finding warrants further scrutiny to determine if the placement is related to a horizontal gene transfer event. Here, the nifH UCYN-B gene copy number from a recent synthesis effort was used as a proxy for relative C. watsonii abundance to examine patterns of C. watsonii distribution as a function of environmental factors, like iron and phosphorus concentration, and complimented with a synthesis of C. watsonii physiology. Furthermore, we have summarized the current knowledge of C. watsonii with regards to N2 fixation, photosynthesis, and quantitative modeling of physiology. Because N availability can limit primary production, C. watsonii is widely recognized for its importance to carbon and N cycling in ocean ecosystems, and we conclude this review by highlighting important topics for further research on this important species.
Collapse
Affiliation(s)
- Takako Masuda
- Institute of Microbiology, The Czech Academy of Sciences, Třeboň, Czech Republic
- Japan Fisheries Research and Education Agency, Shiogama, Miyagi, Japan
| | - Jan Mareš
- Institute of Microbiology, The Czech Academy of Sciences, Třeboň, Czech Republic
- Institute of Hydrobiology, Biology Centre, The Czech Academy of Sciences, České Budejovice, Czech Republic
| | - Takuhei Shiozaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Keisuke Inomura
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA
| | - Amane Fujiwara
- Research Institute for Global Change, JAMSTEC, Yokosuka, Japan
| | - Ondřej Prášil
- Institute of Microbiology, The Czech Academy of Sciences, Třeboň, Czech Republic
| |
Collapse
|
2
|
Akhtar P, Jana S, Lambrev PH, Tan HS. Inhomogeneous energy transfer dynamics from iron-stress-induced protein A to photosystem I. FRONTIERS IN PLANT SCIENCE 2024; 15:1393886. [PMID: 38817933 PMCID: PMC11137255 DOI: 10.3389/fpls.2024.1393886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 04/30/2024] [Indexed: 06/01/2024]
Abstract
Cyanobacteria respond to iron limitation by producing the pigment-protein complex IsiA, forming rings associated with photosystem I (PSI). Initially considered a chlorophyll-storage protein, IsiA is known to act as an auxiliary light-harvesting antenna of PSI, increasing its absorption cross-section and reducing the need for iron-rich PSI core complexes. Spectroscopic studies have demonstrated efficient energy transfer from IsiA to PSI. Here we investigate the room-temperature excitation dynamics in isolated PSI-IsiA, PSI, IsiA monomer complexes and IsiA aggregates using two-dimensional electronic spectroscopy. Cross analyses of the data from these three samples allow us to resolve components of energy transfer between IsiA and PSI with lifetimes of 2-3 ps and around 20 ps. Structure-based Förster theory calculations predict a single major timescale of IsiA-PSI equilibration, that depends on multiple energy transfer routes between different IsiA subunits in the ring. Despite the experimentally observed lifetime heterogeneity, which is attributed to structural heterogeneity of the supercomplexes, IsiA is found to be a unique, highly efficient, membrane antenna complex in cyanobacteria.
Collapse
Affiliation(s)
- Parveen Akhtar
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Sanjib Jana
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore
| | - Petar H. Lambrev
- Institute of Plant Biology, HUN-REN Biological Research Centre, Szeged, Hungary
| | - Howe-Siang Tan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore
| |
Collapse
|
3
|
Akhtar P, Balog-Vig F, Kuntam S, Tóth SZ, Lambrev PH. Function of iron-stress-induced protein A in cyanobacterial cells with monomeric and trimeric photosystem I. PLANT PHYSIOLOGY 2024; 194:1397-1410. [PMID: 37850879 DOI: 10.1093/plphys/kiad562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/12/2023] [Accepted: 09/24/2023] [Indexed: 10/19/2023]
Abstract
The acclimation of cyanobacteria to iron deficiency is crucial for their survival in natural environments. In response to iron deficiency, many cyanobacterial species induce the production of a pigment-protein complex called iron-stress-induced protein A (IsiA). IsiA proteins associate with photosystem I (PSI) and can function as light-harvesting antennas or dissipate excess energy. They may also serve as chlorophyll storage during iron limitation. In this study, we examined the functional role of IsiA in cells of Synechocystis sp. PCC 6803 grown under iron limitation conditions by measuring the cellular IsiA content and its capability to transfer energy to PSI. We specifically tested the effect of the oligomeric state of PSI by comparing wild-type (WT) Synechocystis sp. PCC 6803 with mutants lacking specific subunits of PSI, namely PsaL/PsaI (PSI subunits XI/VIII) and PsaF/PsaJ (PSI subunits III/IX). Time-resolved fluorescence spectroscopy revealed that IsiA formed functional PSI3-IsiA18 supercomplexes, wherein IsiA effectively transfers energy to PSI on a timescale of 10 ps at room temperature-measured in isolated complexes and in vivo-confirming the primary role of IsiA as an accessory light-harvesting antenna to PSI. However, a notable fraction (40%) remained unconnected to PSI, supporting the notion of a dual functional role of IsiA. Cells with monomeric PSI under iron deficiency contained, on average, only 3 to 4 IsiA complexes bound to PSI. These results show that IsiA can transfer energy to trimeric and monomeric PSI but to varying degrees and that the acclimatory production of IsiA under iron stress is controlled by its ability to perform its light-harvesting function.
Collapse
Affiliation(s)
- Parveen Akhtar
- HUN-REN Biological Research Centre, Szeged, Institute of Plant Biology, Temesvári krt. 62, Szeged 6726, Hungary
| | - Fanny Balog-Vig
- HUN-REN Biological Research Centre, Szeged, Institute of Plant Biology, Temesvári krt. 62, Szeged 6726, Hungary
| | - Soujanya Kuntam
- HUN-REN Biological Research Centre, Szeged, Institute of Plant Biology, Temesvári krt. 62, Szeged 6726, Hungary
| | - Szilvia Z Tóth
- HUN-REN Biological Research Centre, Szeged, Institute of Plant Biology, Temesvári krt. 62, Szeged 6726, Hungary
| | - Petar H Lambrev
- HUN-REN Biological Research Centre, Szeged, Institute of Plant Biology, Temesvári krt. 62, Szeged 6726, Hungary
| |
Collapse
|
4
|
Biswas S, Niedzwiedzki DM, Liberton M, Pakrasi HB. Phylogenetic and spectroscopic insights on the evolution of core antenna proteins in cyanobacteria. PHOTOSYNTHESIS RESEARCH 2023:10.1007/s11120-023-01046-6. [PMID: 37737529 DOI: 10.1007/s11120-023-01046-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 08/31/2023] [Indexed: 09/23/2023]
Abstract
Light harvesting by antenna systems is the initial step in a series of electron-transfer reactions in all photosynthetic organisms, leading to energy trapping by reaction center proteins. Cyanobacteria are an ecologically diverse group and are the simplest organisms capable of oxygenic photosynthesis. The primary light-harvesting antenna in cyanobacteria is the large membrane extrinsic pigment-protein complex called the phycobilisome. In addition, cyanobacteria have also evolved specialized membrane-intrinsic chlorophyll-binding antenna proteins that transfer excitation energy to the reaction centers of photosystems I and II (PSI and PSII) and dissipate excess energy through nonphotochemical quenching. Primary among these are the CP43 and CP47 proteins of PSII, but in addition, some cyanobacteria also use IsiA and the prochlorophyte chlorophyll a/b binding (Pcb) family of proteins. Together, these proteins comprise the CP43 family of proteins owing to their sequence similarity with CP43. In this article, we have revisited the evolution of these chlorophyll-binding antenna proteins by examining their protein sequences in parallel with their spectral properties. Our phylogenetic and spectroscopic analyses support the idea of a common ancestor for CP43, IsiA, and Pcb proteins, and suggest that PcbC might be a distant ancestor of IsiA. The similar spectral properties of CP47 and IsiA suggest a closer evolutionary relationship between these proteins compared to CP43.
Collapse
Affiliation(s)
- Sandeep Biswas
- Department of Biology, Washington University, St. Louis, MO, 63130, USA
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University, St. Louis, MO, 63130, USA
- Department of Energy, Environmental and Chemical Engineering, Washington University, St. Louis, MO, 63130, USA
| | - Michelle Liberton
- Department of Biology, Washington University, St. Louis, MO, 63130, USA
| | - Himadri B Pakrasi
- Department of Biology, Washington University, St. Louis, MO, 63130, USA.
| |
Collapse
|
5
|
Harris D, Toporik H, Schlau-Cohen GS, Mazor Y. Energetic robustness to large scale structural fluctuations in a photosynthetic supercomplex. Nat Commun 2023; 14:4650. [PMID: 37532717 PMCID: PMC10397321 DOI: 10.1038/s41467-023-40146-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 07/14/2023] [Indexed: 08/04/2023] Open
Abstract
Photosynthetic organisms transport and convert solar energy with near-unity quantum efficiency using large protein supercomplexes held in flexible membranes. The individual proteins position chlorophylls to tight tolerances considered critical for fast and efficient energy transfer. The variability in protein organization within the supercomplexes, and how efficiency is maintained despite variability, had been unresolved. Here, we report on structural heterogeneity in the 2-MDa cyanobacterial PSI-IsiA photosynthetic supercomplex observed using Cryo-EM, revealing large-scale variances in the positions of IsiA relative to PSI. Single-molecule measurements found efficient IsiA-to-PSI energy transfer across all conformations, along with signatures of transiently decoupled IsiA. Structure based calculations showed that rapid IsiA-to-PSI energy transfer is always maintained, and even increases by three-fold in rare conformations via IsiA-specific chls. We postulate that antennae design mitigates structural fluctuations, providing a mechanism for robust energy transfer in the flexible membrane.
Collapse
Affiliation(s)
- Dvir Harris
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Hila Toporik
- Biodesign Institute, School of Molecular Sciences, Arizona State University, Tempe, AZ, 85801, USA
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Gabriela S Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA.
| | - Yuval Mazor
- Biodesign Institute, School of Molecular Sciences, Arizona State University, Tempe, AZ, 85801, USA.
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.
| |
Collapse
|
6
|
Nagao R, Kato K, Hamaguchi T, Ueno Y, Tsuboshita N, Shimizu S, Furutani M, Ehira S, Nakajima Y, Kawakami K, Suzuki T, Dohmae N, Akimoto S, Yonekura K, Shen JR. Structure of a monomeric photosystem I core associated with iron-stress-induced-A proteins from Anabaena sp. PCC 7120. Nat Commun 2023; 14:920. [PMID: 36805598 PMCID: PMC9938196 DOI: 10.1038/s41467-023-36504-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 02/03/2023] [Indexed: 02/19/2023] Open
Abstract
Iron-stress-induced-A proteins (IsiAs) are expressed in cyanobacteria under iron-deficient conditions. The cyanobacterium Anabaena sp. PCC 7120 has four isiA genes; however, their binding property and functional roles in PSI are still missing. We analyzed a cryo-electron microscopy structure of a PSI-IsiA supercomplex isolated from Anabaena grown under an iron-deficient condition. The PSI-IsiA structure contains six IsiA subunits associated with the PsaA side of a PSI core monomer. Three of the six IsiA subunits were identified as IsiA1 and IsiA2. The PSI-IsiA structure lacks a PsaL subunit; instead, a C-terminal domain of IsiA2 occupies the position of PsaL, which inhibits the oligomerization of PSI, leading to the formation of a PSI monomer. Furthermore, excitation-energy transfer from IsiAs to PSI appeared with a time constant of 55 ps. These findings provide insights into both the molecular assembly of the Anabaena IsiA family and the functional roles of IsiAs.
Collapse
Affiliation(s)
- Ryo Nagao
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan. .,Faculty of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan.
| | - Koji Kato
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.,Structural Biology Division, Japan Synchrotron Radiation Research Institute (JASRI), Hyogo, 679-5198, Japan
| | - Tasuku Hamaguchi
- Biostructural Mechanism Laboratory, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan.,Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Miyagi, 980-8577, Japan
| | - Yoshifumi Ueno
- Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan.,Institute of Arts and Science, Tokyo University of Science, Tokyo, 162-8601, Japan
| | - Naoki Tsuboshita
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Shota Shimizu
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Miyu Furutani
- Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan
| | - Shigeki Ehira
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo, 192-0397, Japan
| | - Yoshiki Nakajima
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan
| | - Keisuke Kawakami
- Biostructural Mechanism Laboratory, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama, 351-0198, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama, 351-0198, Japan
| | - Seiji Akimoto
- Graduate School of Science, Kobe University, Hyogo, 657-8501, Japan.
| | - Koji Yonekura
- Biostructural Mechanism Laboratory, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan. .,Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Miyagi, 980-8577, Japan. .,Advanced Electron Microscope Development Unit, RIKEN-JEOL Collaboration Center, RIKEN Baton Zone Program, Hyogo, 679-5148, Japan.
| | - Jian-Ren Shen
- Research Institute for Interdisciplinary Science and Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
| |
Collapse
|
7
|
Photosynthesis tunes quantum-mechanical mixing of electronic and vibrational states to steer exciton energy transfer. Proc Natl Acad Sci U S A 2021; 118:2018240118. [PMID: 33688046 DOI: 10.1073/pnas.2018240118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Photosynthetic species evolved to protect their light-harvesting apparatus from photoxidative damage driven by intracellular redox conditions or environmental conditions. The Fenna-Matthews-Olson (FMO) pigment-protein complex from green sulfur bacteria exhibits redox-dependent quenching behavior partially due to two internal cysteine residues. Here, we show evidence that a photosynthetic complex exploits the quantum mechanics of vibronic mixing to activate an oxidative photoprotective mechanism. We use two-dimensional electronic spectroscopy (2DES) to capture energy transfer dynamics in wild-type and cysteine-deficient FMO mutant proteins under both reducing and oxidizing conditions. Under reducing conditions, we find equal energy transfer through the exciton 4-1 and 4-2-1 pathways because the exciton 4-1 energy gap is vibronically coupled with a bacteriochlorophyll-a vibrational mode. Under oxidizing conditions, however, the resonance of the exciton 4-1 energy gap is detuned from the vibrational mode, causing excitons to preferentially steer through the indirect 4-2-1 pathway to increase the likelihood of exciton quenching. We use a Redfield model to show that the complex achieves this effect by tuning the site III energy via the redox state of its internal cysteine residues. This result shows how pigment-protein complexes exploit the quantum mechanics of vibronic coupling to steer energy transfer.
Collapse
|
8
|
do Nascimento EL, Koschek PR, Dos Santos MEV, Pacheco ABF, Gomes AMDA, de Souza CMM, Bastos WR, de Oliveira Azevedo SMF. Influence of Iron on Physiological Parameters and Intracellular Microcystin in Microcystis Panniformis Strain Isolated from a Reservoir in the Amazon. Curr Microbiol 2021; 78:2345-2354. [PMID: 33913000 DOI: 10.1007/s00284-021-02499-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 04/16/2021] [Indexed: 11/28/2022]
Abstract
In the Amazon, the leaching from soil left unprotected by deforestation increases the entry of iron, among other elements, in aquatic ecosystems, which can cause cyanobacterial blooms. This study aimed to investigate the physiological response of a strain of Microcystis panniformis to iron variation. The strain was isolated from a reservoir located in the Western Amazon and produces microcystin-LR. After a period of iron deprivation, the cultures were submitted to three conditions: control (223 μgFe.L-1), treatment with 23 μgFe.L-1, and absence of iron. At regular intervals for eight days, the cell density, levels of chlorophyll a and microcystins were determined. On the second and fourth day, transcription of genes responsive to iron limitation was quantified. Starting on the fourth day of the experiment, the different iron concentrations affected growth, and on the eighth day in the iron-free condition cell density was 90% lower than in control. Chlorophyll cell quota in 23 μgFe.L-1 and control presented similar values, while without iron the cells became chlorotic as of the fourth day Toxin concentration in cells grow in 0 μgFe.L-1 in relation to the control. Higher transcription levels of the feo and fut genes were observed in the 0 μgFe.L-1 and 23 μgFe.L-1 treatments, indicating that the cells were activating high-affinity capture systems to reestablish an adequate concentration of intracellular iron. The increasing deforestation in the Jamari River Basin (Amazon region), can contribute to the occurrence of toxic cyanobacterial blooms due to the greater entrance of iron in water bodies.
Collapse
Affiliation(s)
- Elisabete Lourdes do Nascimento
- Grupo de Pesquisa em Águas Superficiais e Subterrâneas, Laboratório de Limnologia e Microbiologia, Fundação Universidade Federal de Rondônia, Ji-Paraná, CEP: 76900-726, Brazil.
| | - Priscila Rodrigues Koschek
- Laboratório de Toxicologia e Ecofisiologia de Cianobactérias, Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro, CEP: 21949-902, Brazil
| | - Maria Elisângela Venâncio Dos Santos
- Laboratório de Toxicologia e Ecofisiologia de Cianobactérias, Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro, CEP: 21949-902, Brazil
| | - Ana Beatriz Furlanetto Pacheco
- Laboratório de Física Biológica, Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro, CEP: 21949-902, Brazil
| | - Andreia Maria da Anunciação Gomes
- Instituto Federal de Educação, Ciência e Tecnologia do Rio de Janeiro. Avenida Professor Plínio Leite, Niterói, CEP: 2402-001, Brazil
| | | | - Wanderley Rodrigues Bastos
- Laboratório de Biogeoquímica Ambiental Wolfgang C. Pfeiffer, Fundação Universidade Federal de Rondônia, Porto Velho, CEP: 76801-016, Brazil
| | - Sandra Maria Feliciano de Oliveira Azevedo
- Laboratório de Toxicologia e Ecofisiologia de Cianobactérias, Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro, CEP: 21949-902, Brazil
| |
Collapse
|
9
|
Abstract
Oxygenic photosynthetic organisms have evolved a multitude of mechanisms for protection against high-light stress. IsiA, a chlorophyll a-binding cyanobacterial protein, serves as an accessory antenna complex for photosystem I. Intriguingly, IsiA can also function as an independent pigment protein complex in the thylakoid membrane and facilitate the dissipation of excess energy, providing photoprotection. The molecular basis of the IsiA-mediated excitation quenching mechanism remains poorly understood. In this study, we demonstrate that IsiA uses a novel cysteine-mediated process to quench excitation energy. The single cysteine in IsiA in the cyanobacterium Synechocystis sp. strain PCC 6803 was converted to a valine. Ultrafast fluorescence spectroscopic analysis showed that this single change abolishes the excitation energy quenching ability of IsiA, thus providing direct evidence of the crucial role of this cysteine residue in energy dissipation from excited chlorophylls. Under stress conditions, the mutant cells exhibited enhanced light sensitivity, indicating that the cysteine-mediated quenching process is critically important for photoprotection.
Collapse
|
10
|
Molecular organizations and function of iron-stress-induced-A protein family in Anabaena sp. PCC 7120. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148327. [PMID: 33069682 DOI: 10.1016/j.bbabio.2020.148327] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/29/2020] [Accepted: 10/13/2020] [Indexed: 11/22/2022]
Abstract
Iron-stress-induced-A proteins (IsiAs) are expressed in cyanobacteria under iron-deficient conditions, and surround photosystem I (PSI) trimer with a ring formation. A cyanobacterium Anabaena sp. PCC 7120 has four isiA genes; however, it is unknown how the IsiAs are associated with PSI. Here we report on molecular organizations and function of the IsiAs in this cyanobacterium. A deletion mutant of the isiA1 gene was constructed, and the four types of thylakoids were prepared from the wild-type (WT) and ΔisiA1 cells under iron-replete (+Fe) and iron-deficient (-Fe) conditions. Immunoblotting analysis exhibits a clear expression of the IsiA1 in the WT-Fe. The PSI-IsiA1 supercomplex is found in the WT-Fe, and excitation-energy transfer from IsiA1 to PSI is verified by time-resolved fluorescence analyses. Instead of the IsiA1, both IsiA2 and IsiA3 are bound to PSI monomer in the ΔisiA1-Fe. These findings provide insights into multiple-expression system of the IsiA family in this cyanobacterium.
Collapse
|
11
|
Schoffman H, Brown WM, Paltiel Y, Keren N, Gauger EM. Structure-based Hamiltonian model for IsiA uncovers a highly robust pigment-protein complex. J R Soc Interface 2020; 17:20200399. [PMID: 32842892 PMCID: PMC7482578 DOI: 10.1098/rsif.2020.0399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/04/2020] [Indexed: 11/12/2022] Open
Abstract
The iron stress-induced protein A (IsiA) is a source of interest and debate in biological research. The IsiA supercomplex, binding over 200 chlorophylls, assembles in multimeric rings around photosystem I (PSI). Recently, the IsiA-PSI structure from Synechocystis sp. PCC 6803 was resolved to 3.48 Å. Based on this structure, we created a model simulating a single excitation event in an IsiA monomer. This model enabled us to calculate the fluorescence and the localization of the excitation in the IsiA structure. To further examine this system, noise was introduced to the model in two forms-thermal and positional. Introducing noise highlights the functional differences in the system between cryogenic temperatures and biologically relevant temperatures. Our results show that the energetics of the IsiA pigment-protein complex are very robust at room temperature. Nevertheless, shifts in the position of specific chlorophylls lead to large changes in their optical and fluorescence properties. Based on these results, we discuss the implication of highly robust structures, with potential for serving different roles in a context-dependent manner, on our understanding of the function and evolution of photosynthetic processes.
Collapse
Affiliation(s)
- Hanan Schoffman
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - William M. Brown
- SUPA, Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
| | - Yossi Paltiel
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Erik M. Gauger
- SUPA, Institute of Photonics and Quantum Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK
| |
Collapse
|
12
|
Structure of a cyanobacterial photosystem I surrounded by octadecameric IsiA antenna proteins. Commun Biol 2020; 3:232. [PMID: 32393811 PMCID: PMC7214436 DOI: 10.1038/s42003-020-0949-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 04/17/2020] [Indexed: 11/13/2022] Open
Abstract
Iron-stress induced protein A (IsiA) is a chlorophyll-binding membrane-spanning protein in photosynthetic prokaryote cyanobacteria, and is associated with photosystem I (PSI) trimer cores, but its structural and functional significance in light harvesting remains unclear. Here we report a 2.7-Å resolution cryo-electron microscopic structure of a supercomplex between PSI core trimer and IsiA from a thermophilic cyanobacterium Thermosynechococcus vulcanus. The structure showed that 18 IsiA subunits form a closed ring surrounding a PSI trimer core. Detailed arrangement of pigments within the supercomplex, as well as molecular interactions between PSI and IsiA and among IsiAs, were resolved. Time-resolved fluorescence spectra of the PSI–IsiA supercomplex showed clear excitation-energy transfer from IsiA to PSI, strongly indicating that IsiA functions as an energy donor, but not an energy quencher, in the supercomplex. These structural and spectroscopic findings provide important insights into the excitation-energy-transfer and subunit assembly mechanisms in the PSI–IsiA supercomplex. Akita et al. present the latest approach to solve IsiA–PSI supercomplex molecular structure with increased resolution using cryo-EM and time-resolved fluorescence studies. With 2.7 Å resolution, they reveal molecular interactions between PSI and IsiA subunits and that IsiA functions as an energy donor in the supercomplex.
Collapse
|
13
|
Schoffman H, Keren N. Function of the IsiA pigment-protein complex in vivo. PHOTOSYNTHESIS RESEARCH 2019; 141:343-353. [PMID: 30929163 DOI: 10.1007/s11120-019-00638-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 03/18/2019] [Indexed: 06/09/2023]
Abstract
The acclimation of cyanobacterial photosynthetic apparatus to iron deficiency is crucial for their performance under limiting conditions. In many cyanobacterial species, one of the major responses to iron deficiency is the induction of isiA. The function of the IsiA pigment-protein complex has been the subject of intensive research. In this study of the model Synechocystis sp. PCC 6803 strain, we probe the accumulation of the pigment-protein complex and its effects on in vivo photosynthetic performance. We provide evidence that in this organism the dominant factor controlling IsiA accumulation is the intracellular iron concentration and not photo-oxidative stress or redox poise. These findings support the use of IsiA as a tool for assessing iron bioavailability in environmental studies. We also present evidence demonstrating that the IsiA pigment-protein complex exerts only small effects on the performance of the reaction centers. We propose that its major function is as a storage depot able to hold up to 50% of the cellular chlorophyll content during transition into iron limitation. During recovery from iron limitation, chlorophyll is released from the complex and used for the reconstruction of photosystems. Therefore, the IsiA pigment-protein complex can play a critical role not only when cells transition into iron limitation, but also in supporting efficient recovery of the photosynthetic apparatus in the transition back out of the iron-limited state.
Collapse
Affiliation(s)
- Hanan Schoffman
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel
| | - Nir Keren
- Department of Plant and Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, Israel.
| |
Collapse
|
14
|
Toporik H, Li J, Williams D, Chiu PL, Mazor Y. The structure of the stress-induced photosystem I-IsiA antenna supercomplex. Nat Struct Mol Biol 2019; 26:443-449. [PMID: 31133699 DOI: 10.1038/s41594-019-0228-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 04/11/2019] [Indexed: 01/20/2023]
Abstract
Photochemical conversion in oxygenic photosynthesis takes place in two large protein-pigment complexes named photosystem II and photosystem I (PSII and PSI, respectively). Photosystems associate with antennae in vivo to increase the size of photosynthetic units to hundreds or thousands of pigments. Regulation of the interactions between antennae and photosystems allows photosynthetic organisms to adapt to their environment. In low-iron environments, cyanobacteria express IsiA, a PSI antenna, critical to their survival. Here we describe the structure of the PSI-IsiA complex isolated from the mesophilic cyanobacterium Synechocystis sp. PCC 6803. This 2-MDa photosystem-antenna supercomplex structure reveals more than 700 pigments coordinated by 51 subunits, as well as the mechanisms facilitating the self-assembly and association of IsiA with multiple PSI assemblies.
Collapse
Affiliation(s)
- Hila Toporik
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - Jin Li
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - Dewight Williams
- John M. Cowley Center for High Resolution Electron Microscopy, Arizona State University, Tempe, AZ, USA
| | - Po-Lin Chiu
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - Yuval Mazor
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA. .,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA.
| |
Collapse
|
15
|
Bar-Zvi S, Lahav A, Harris D, Niedzwiedzki DM, Blankenship RE, Adir N. Structural heterogeneity leads to functional homogeneity in A. marina phycocyanin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:544-553. [DOI: 10.1016/j.bbabio.2018.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/18/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022]
|
16
|
Li ZK, Yin YC, Zhang LD, Zhang ZC, Dai GZ, Chen M, Qiu BS. The identification of IsiA proteins binding chlorophyll d in the cyanobacterium Acaryochloris marina. PHOTOSYNTHESIS RESEARCH 2018; 135:165-175. [PMID: 28378245 DOI: 10.1007/s11120-017-0379-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 03/30/2017] [Indexed: 06/07/2023]
Abstract
The bioavailable iron in many aquatic ecosystems is extremely low, and limits the growth and photosynthetic activity of phytoplankton. In response to iron limitation, a group of chlorophyll-binding proteins known as iron stress-induced proteins are induced and serve as accessory light-harvesting components for photosystems under iron limitation. In the present study, we investigated physiological features of Acaryochloris marina in response to iron-deficient conditions. The growth doubling time under iron-deficient conditions was prolonged to ~3.4 days compared with 1.9 days under normal culture conditions, accompanied with dramatically decreased chlorophyll content. The isolation of chlorophyll-binding protein complexes using sucrose density gradient centrifugation shows six main green bands and three main fluorescence components of 712, 728, and 748 nm from the iron-deficient culture. The fluorescence components of 712 and 728 nm co-exist in the samples collected from iron-deficient and iron-replete cultures and are attributed to Chl d-binding accessory chlorophyll-binding antenna proteins and also from photosystem II. A new chlorophyll-binding protein complex with its main fluorescence peak at 748 nm was observed and enriched in the heaviest fraction from the samples collected from the iron-deficient culture only. Combining western blotting analysis using antibodies of CP47 (PSII), PsaC (PSI) and IsiA and proteomic analysis on an excised protein band at ~37 kDa, the heaviest fraction (-F6) isolated from iron-deficient culture contained Chl d-bound PSI-IsiA supercomplexes. The PSII-antenna supercomplexes isolated from iron-replete conditions showed two fluorescence peaks of 712 and 728 nm, which can be assigned as 6-transmembrane helix chlorophyll-binding antenna and photosystem II fluorescence, respectively, which is supported by protein analysis of the fractions (F5 and F6).
Collapse
Affiliation(s)
- Zheng-Ke Li
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, Hubei, People's Republic of China
| | - Yan-Chao Yin
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, Hubei, People's Republic of China
| | - Lu-Dan Zhang
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, Hubei, People's Republic of China
| | - Zhong-Chun Zhang
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, Hubei, People's Republic of China
| | - Guo-Zheng Dai
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, Hubei, People's Republic of China
| | - Min Chen
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, 2006, Australia.
| | - Bao-Sheng Qiu
- School of Life Sciences, and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, Hubei, People's Republic of China.
| |
Collapse
|
17
|
Magdaong NCM, Blankenship RE. Photoprotective, excited-state quenching mechanisms in diverse photosynthetic organisms. J Biol Chem 2018; 293:5018-5025. [PMID: 29298897 DOI: 10.1074/jbc.tm117.000233] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Light-harvesting complexes (LHCs) serve a dual role in photosynthesis, depending on the prevailing light conditions. In low light, they ensure photosynthetic efficiency by maximizing the light absorption cross-section and subsequent energy storage. Under excess light conditions, LHCs perform photoprotective quenching functions to prevent harmful chemical species such as triplet chlorophyll and singlet oxygen from forming and damaging the photosynthetic apparatus. In this Minireview, various photoprotective quenching mechanisms that have been identified in different photosynthetic organisms are surveyed and summarized, and implications for improving photosynthetic productivity are briefly discussed.
Collapse
Affiliation(s)
- Nikki Cecil M Magdaong
- From the Departments of Biology and Chemistry and.,the Photosynthetic Antenna Research Center, Washington University in Saint Louis, St. Louis, Missouri 63130
| | - Robert E Blankenship
- From the Departments of Biology and Chemistry and .,the Photosynthetic Antenna Research Center, Washington University in Saint Louis, St. Louis, Missouri 63130
| |
Collapse
|
18
|
Hernández-Prieto MA, Li Y, Postier BL, Blankenship RE, Chen M. Far-red light promotes biofilm formation in the cyanobacteriumAcaryochloris marina. Environ Microbiol 2017; 20:535-545. [DOI: 10.1111/1462-2920.13961] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 01/07/2023]
Affiliation(s)
- Miguel A. Hernández-Prieto
- ARC Centre of Excellence for Translational Photosynthesis and School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
| | - Yaqiong Li
- ARC Centre of Excellence for Translational Photosynthesis and School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
| | - Bradley L. Postier
- Departments of Biology and Chemistry; Washington University in St. Louis; St. Louis MO 63130 USA
| | - Robert E. Blankenship
- Departments of Biology and Chemistry; Washington University in St. Louis; St. Louis MO 63130 USA
| | - Min Chen
- ARC Centre of Excellence for Translational Photosynthesis and School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
| |
Collapse
|
19
|
Bar Eyal L, Ranjbar Choubeh R, Cohen E, Eisenberg I, Tamburu C, Dorogi M, Ünnep R, Appavou MS, Nevo R, Raviv U, Reich Z, Garab G, van Amerongen H, Paltiel Y, Keren N. Changes in aggregation states of light-harvesting complexes as a mechanism for modulating energy transfer in desert crust cyanobacteria. Proc Natl Acad Sci U S A 2017; 114:9481-9486. [PMID: 28808031 PMCID: PMC5584450 DOI: 10.1073/pnas.1708206114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
In this paper we propose an energy dissipation mechanism that is completely reliant on changes in the aggregation state of the phycobilisome light-harvesting antenna components. All photosynthetic organisms regulate the efficiency of excitation energy transfer (EET) to fit light energy supply to biochemical demands. Not many do this to the extent required of desert crust cyanobacteria. Following predawn dew deposition, they harvest light energy with maximum efficiency until desiccating in the early morning hours. In the desiccated state, absorbed energy is completely quenched. Time and spectrally resolved fluorescence emission measurements of the desiccated desert crust Leptolyngbya ohadii strain identified (i) reduced EET between phycobilisome components, (ii) shorter fluorescence lifetimes, and (iii) red shift in the emission spectra, compared with the hydrated state. These changes coincide with a loss of the ordered phycobilisome structure, evident from small-angle neutron and X-ray scattering and cryo-transmission electron microscopy data. Based on these observations we propose a model where in the hydrated state the organized rod structure of the phycobilisome supports directional EET to reaction centers with minimal losses due to thermal dissipation. In the desiccated state this structure is lost, giving way to more random aggregates. The resulting EET path will exhibit increased coupling to the environment and enhanced quenching.
Collapse
Affiliation(s)
- Leeat Bar Eyal
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Reza Ranjbar Choubeh
- Laboratory of Biophysics, Wageningen University, 6700 ET Wageningen, The Netherlands
| | - Eyal Cohen
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ido Eisenberg
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Carmen Tamburu
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Márta Dorogi
- Biological Research Centre, Hungarian Academy of Sciences, Szeged 6726, Hungary
| | - Renata Ünnep
- Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest 114, Hungary
| | - Marie-Sousai Appavou
- Jülich Centre for Neutron Science at Heinz Maier-Leibnitz Zentrum, Forschungszentrum Jülich GmbH, 85748 Garching, Germany
| | - Reinat Nevo
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600, Israel
| | - Uri Raviv
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Ziv Reich
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7600, Israel
| | - Győző Garab
- Biological Research Centre, Hungarian Academy of Sciences, Szeged 6726, Hungary
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, 6700 ET Wageningen, The Netherlands
| | - Yossi Paltiel
- Applied Physics Department, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Nir Keren
- Department of Plant & Environmental Sciences, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel;
| |
Collapse
|
20
|
Light harvesting in phototrophic bacteria: structure and function. Biochem J 2017; 474:2107-2131. [DOI: 10.1042/bcj20160753] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 12/23/2022]
Abstract
This review serves as an introduction to the variety of light-harvesting (LH) structures present in phototrophic prokaryotes. It provides an overview of the LH complexes of purple bacteria, green sulfur bacteria (GSB), acidobacteria, filamentous anoxygenic phototrophs (FAP), and cyanobacteria. Bacteria have adapted their LH systems for efficient operation under a multitude of different habitats and light qualities, performing both oxygenic (oxygen-evolving) and anoxygenic (non-oxygen-evolving) photosynthesis. For each LH system, emphasis is placed on the overall architecture of the pigment–protein complex, as well as any relevant information on energy transfer rates and pathways. This review addresses also some of the more recent findings in the field, such as the structure of the CsmA chlorosome baseplate and the whole-cell kinetics of energy transfer in GSB, while also pointing out some areas in need of further investigation.
Collapse
|