1
|
Kumazawa M, Ifuku K. Unraveling the evolutionary trajectory of LHCI in red-lineage algae: Conservation, diversification, and neolocalization. iScience 2024; 27:110897. [PMID: 39386759 PMCID: PMC11462038 DOI: 10.1016/j.isci.2024.110897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 07/21/2024] [Accepted: 09/04/2024] [Indexed: 10/12/2024] Open
Abstract
Red algae and the secondary symbiotic algae that engulfed a red alga as an endosymbiont are called red-lineage algae. Several photosystem (PS) I-light-harvesting complex I (LHCI) structures have been reported from red-lineage algae-two red algae Cyanidioschyzon merolae (Cyanidiophyceae) and Porphyridium purpureum (Rhodophytina), a diatom, and a Cryptophyte. Here, we clarified the orthologous relation of LHCIs by combining a detailed phylogenetic analysis and the structural information of PSI-LHCI. We found that the seven Lhcr groups in LHCI are conserved in Rhodophytina; furthermore, during both genome reduction in Cyanidioschyzonales and endosymbiosis leading to Cryptophyta, some LHCIs were lost and replaced by existing or differentiated LHCIs. We denominate "neolocalization" to these examples of flexible reorganization of LHCIs. This study provides insights into the evolutionary process of LHCIs in red-lineage algae and clarifies the need for both molecular phylogeny and structural information to elucidate the plausible evolutionary history of LHCI.
Collapse
Affiliation(s)
- Minoru Kumazawa
- Graduate School of Agriculture, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| | - Kentaro Ifuku
- Graduate School of Agriculture, Kyoto University, Kyoto, Kyoto 606-8502, Japan
| |
Collapse
|
2
|
Eckardt NA, Allahverdiyeva Y, Alvarez CE, Büchel C, Burlacot A, Cardona T, Chaloner E, Engel BD, Grossman AR, Harris D, Herrmann N, Hodges M, Kern J, Kim TD, Maurino VG, Mullineaux CW, Mustila H, Nikkanen L, Schlau-Cohen G, Tronconi MA, Wietrzynski W, Yachandra VK, Yano J. Lighting the way: Compelling open questions in photosynthesis research. THE PLANT CELL 2024; 36:3914-3943. [PMID: 39038210 PMCID: PMC11449116 DOI: 10.1093/plcell/koae203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 05/29/2024] [Accepted: 07/15/2024] [Indexed: 07/24/2024]
Abstract
Photosynthesis-the conversion of energy from sunlight into chemical energy-is essential for life on Earth. Yet there is much we do not understand about photosynthetic energy conversion on a fundamental level: how it evolved and the extent of its diversity, its dynamics, and all the components and connections involved in its regulation. In this commentary, researchers working on fundamental aspects of photosynthesis including the light-dependent reactions, photorespiration, and C4 photosynthetic metabolism pose and discuss what they view as the most compelling open questions in their areas of research.
Collapse
Affiliation(s)
| | - Yagut Allahverdiyeva
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, 20014 Turku, Finland
| | - Clarisa E Alvarez
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Facultad de Ciencias Bioquímicas y Farmacuticas, University of Rosario, Suipacha 570, 2000 Rosario, Argentina
| | - Claudia Büchel
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt, Germany
| | - Adrien Burlacot
- Division of Bioscience and Engineering, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Tanai Cardona
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Emma Chaloner
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Benjamin D Engel
- Biozentrum, University of Basel, Sptialstrasse 41, 4056 Basel, Switzerland
| | - Arthur R Grossman
- Division of Bioscience and Engineering, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Dvir Harris
- Department of Chemistry, Massachusetts Institute of Technology, Massachusetts Ave, Cambridge, MA 02139, USA
| | - Nicolas Herrmann
- Institute of Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt, Germany
| | - Michael Hodges
- Université Paris-Saclay, CNRS, INRAE, Université d’Evry, Université de Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Tom Dongmin Kim
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Veronica G Maurino
- Molecular Plant Physiology, Institute for Cellular and Molecular Botany (IZMB), University of Bonn, Kirschallee 1, 53115 Bonn, Germany
| | - Conrad W Mullineaux
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Henna Mustila
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, 20014 Turku, Finland
| | - Lauri Nikkanen
- Molecular Plant Biology Unit, Department of Life Technologies, University of Turku, 20014 Turku, Finland
| | - Gabriela Schlau-Cohen
- Department of Chemistry, Massachusetts Institute of Technology, Massachusetts Ave, Cambridge, MA 02139, USA
| | - Marcos A Tronconi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Facultad de Ciencias Bioquímicas y Farmacuticas, University of Rosario, Suipacha 570, 2000 Rosario, Argentina
| | | | - Vittal K Yachandra
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| |
Collapse
|
3
|
Zarif M, Rousselot E, Jesus B, Tirichine L, Duc C. H3K27me3 and EZH Are Involved in the Control of the Heat-Stress-Elicited Morphological Changes in Diatoms. Int J Mol Sci 2024; 25:8373. [PMID: 39125941 PMCID: PMC11313476 DOI: 10.3390/ijms25158373] [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: 06/28/2024] [Revised: 07/23/2024] [Accepted: 07/27/2024] [Indexed: 08/12/2024] Open
Abstract
Marine water temperatures are increasing due to anthropogenic climate change, constituting a major threat to marine ecosystems. Diatoms are major marine primary producers, and as such, they are subjected to marine heat waves and rising ocean temperatures. Additionally, under low tide, diatoms are regularly exposed to high temperatures. However, physiological and epigenetic responses to long-term exposure to heat stress remain largely unknown in the diatom Phaeodactylum tricornutum. In this study, we investigated changes in cell morphology, photosynthesis, and H3K27me3 abundance (an epigenetic mark consisting of the tri-methylation of lysine 27 on histone H3) after moderate and elevated heat stresses. Mutants impaired in PtEZH-the enzyme depositing H3K27me3-presented reduced growth and moderate changes in their PSII quantum capacities. We observed shape changes for the three morphotypes of P. tricornutum (fusiform, oval, and triradiate) in response to heat stress. These changes were found to be under the control of PtEZH. Additionally, both moderate and elevated heat stresses modulated the expression of genes encoding proteins involved in photosynthesis. Finally, heat stress elicited a reduction of genome-wide H3K27me3 levels in the various morphotypes. Hence, we provided direct evidence of epigenetic control of the H3K27me3 mark in the responses of Phaeodactylum tricornutum to heat stress.
Collapse
Affiliation(s)
- Mhammad Zarif
- Nantes Université, CNRS, US2B, UMR 6286, F-44000 Nantes, France; (M.Z.); (L.T.)
| | - Ellyn Rousselot
- Nantes Université, CNRS, US2B, UMR 6286, F-44000 Nantes, France; (M.Z.); (L.T.)
| | - Bruno Jesus
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, F-44000 Nantes, France;
| | - Leïla Tirichine
- Nantes Université, CNRS, US2B, UMR 6286, F-44000 Nantes, France; (M.Z.); (L.T.)
- Institute for Marine and Antarctic Studies (IMAS), Ecology and Biodiversity Centre, University of Tasmania, Hobart, TAS 7004, Australia
| | - Céline Duc
- Nantes Université, CNRS, US2B, UMR 6286, F-44000 Nantes, France; (M.Z.); (L.T.)
| |
Collapse
|
4
|
Zhou C, Feng Y, Li Z, Shen L, Li X, Wang Y, Han G, Kuang T, Liu C, Shen JR, Wang W. Structural and spectroscopic insights into fucoxanthin chlorophyll a/c-binding proteins of diatoms in diverse oligomeric states. PLANT COMMUNICATIONS 2024:101041. [PMID: 39030906 DOI: 10.1016/j.xplc.2024.101041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 06/20/2024] [Accepted: 07/15/2024] [Indexed: 07/22/2024]
Abstract
Diatoms, a group of prevalent marine algae, contribute significantly to global primary productivity. Their substantial biomass is linked to enhanced absorption of blue-green light underwater, facilitated by fucoxanthin chlorophyll (Chl) a/c-binding proteins (FCPs), which exhibit oligomeric diversity across diatom species. Using mild clear native PAGE analysis of solubilized thylakoid membranes, we displayed monomeric, dimeric, trimeric, tetrameric, and pentameric FCPs in diatoms. Mass spectrometry analysis revealed that each oligomeric FCP has a specific protein composition, and together they constitute a large Lhcf family of FCP antennas. In addition, we resolved the structures of the Thalassiosira pseudonana FCP (Tp-FCP) homotrimer and the Chaetoceros gracilis FCP (Cg-FCP) pentamer by cryoelectron microscopy at 2.73-Å and 2.65-Å resolution, respectively. The distinct pigment compositions and organizations of various oligomeric FCPs affect their blue-green light-harvesting, excitation energy transfer pathways. Compared with dimeric and trimeric FCPs, the Cg-FCP tetramer and Cg-FCP pentamer exhibit stronger absorption by Chl c, redshifted and broader Chl a fluorescence emission, and more robust circular dichroism signals originating from Chl a-carotenoid dimers. These spectroscopic characteristics indicate that Chl a molecules in the Cg-FCP tetramer and Cg-FCP pentamer are more heterogeneous than in both dimers and the Tp-FCP trimer. The structural and spectroscopic insights provided by this study contribute to a better understanding of the mechanisms that empower diatoms to adapt to fluctuating light environments.
Collapse
Affiliation(s)
- Cuicui Zhou
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; University of the Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Yue Feng
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; University of the Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Zhenhua Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; University of the Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Lili Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; University of the Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Xiaoyi Li
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; China National Botanical Garden, Beijing 100093, P.R. China; Academician Workstation of the Agricultural High-Tech Industrial Area of the Yellow River Delta, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying 257300, P.R. China
| | - Yumei Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190, P.R. China
| | - Guangye Han
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; China National Botanical Garden, Beijing 100093, P.R. China; Academician Workstation of the Agricultural High-Tech Industrial Area of the Yellow River Delta, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying 257300, P.R. China
| | - Tingyun Kuang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; China National Botanical Garden, Beijing 100093, P.R. China; Academician Workstation of the Agricultural High-Tech Industrial Area of the Yellow River Delta, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying 257300, P.R. China
| | - Cheng Liu
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; China National Botanical Garden, Beijing 100093, P.R. China; Academician Workstation of the Agricultural High-Tech Industrial Area of the Yellow River Delta, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying 257300, P.R. China.
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; Research Institute for Interdisciplinary Science, Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan.
| | - Wenda Wang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China; China National Botanical Garden, Beijing 100093, P.R. China; Academician Workstation of the Agricultural High-Tech Industrial Area of the Yellow River Delta, National Center of Technology Innovation for Comprehensive Utilization of Saline-Alkali Land, Dongying 257300, P.R. China.
| |
Collapse
|
5
|
Zhang YZ, Li K, Qin BY, Guo JP, Zhang QB, Zhao DL, Chen XL, Gao J, Liu LN, Zhao LS. Structure of cryptophyte photosystem II-light-harvesting antennae supercomplex. Nat Commun 2024; 15:4999. [PMID: 38866834 PMCID: PMC11169493 DOI: 10.1038/s41467-024-49453-0] [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: 01/16/2024] [Accepted: 06/06/2024] [Indexed: 06/14/2024] Open
Abstract
Cryptophytes are ancestral photosynthetic organisms evolved from red algae through secondary endosymbiosis. They have developed alloxanthin-chlorophyll a/c2-binding proteins (ACPs) as light-harvesting complexes (LHCs). The distinctive properties of cryptophytes contribute to efficient oxygenic photosynthesis and underscore the evolutionary relationships of red-lineage plastids. Here we present the cryo-electron microscopy structure of the Photosystem II (PSII)-ACPII supercomplex from the cryptophyte Chroomonas placoidea. The structure includes a PSII dimer and twelve ACPII monomers forming four linear trimers. These trimers structurally resemble red algae LHCs and cryptophyte ACPI trimers that associate with Photosystem I (PSI), suggesting their close evolutionary links. We also determine a Chl a-binding subunit, Psb-γ, essential for stabilizing PSII-ACPII association. Furthermore, computational calculation provides insights into the excitation energy transfer pathways. Our study lays a solid structural foundation for understanding the light-energy capture and transfer in cryptophyte PSII-ACPII, evolutionary variations in PSII-LHCII, and the origin of red-lineage LHCIIs.
Collapse
Affiliation(s)
- Yu-Zhong Zhang
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China.
| | - Kang Li
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
| | - Bing-Yue Qin
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jian-Ping Guo
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China
| | - Quan-Bao Zhang
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Dian-Li Zhao
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
| | - Xiu-Lan Chen
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China
| | - Jun Gao
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, China.
| | - Lu-Ning Liu
- MOE Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science Center for Deep Ocean Multispheres and Earth System & College of Marine Life Sciences, Ocean University of China, Qingdao, China.
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK.
| | - Long-Sheng Zhao
- Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China.
| |
Collapse
|
6
|
Akhtar P, Feng Y, Jana S, Wang W, Shen JR, Tan HS, Lambrev PH. Ultrafast Energy Transfer in a Diatom Photosystem II Supercomplex. J Phys Chem Lett 2024; 15:5838-5847. [PMID: 38788163 DOI: 10.1021/acs.jpclett.4c01029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
The light-harvesting complexes (LHCs) of diatoms, specifically fucoxanthin-Chl a/c binding proteins (FCPs), exhibit structural and functional diversity, as highlighted by recent structural studies of photosystem II-FCP (PSII-FCPII) supercomplexes from different diatom species. The excitation dynamics of PSII-FCPII supercomplexes isolated from the diatom Thalassiosira pseudonana was explored using time-resolved fluorescence spectroscopy and two-dimensional electronic spectroscopy at room temperature and 77 K. Energy transfer between FCPII and PSII occurred remarkably fast (<5 ps), emphasizing the efficiency of FCPII as a light-harvesting antenna. The presence of long-wavelength chlorophylls may further help concentrate excitations in the core complex and increase the efficiency of light harvesting. Structure-based calculations reveal remarkably strong excitonic couplings between chlorophylls in the FCP antenna and between FCP and the PSII core antenna that are the basis for the rapid energy transfer.
Collapse
Affiliation(s)
- Parveen Akhtar
- HUN-REN Biological Research Centre, Szeged, Temesvári körút 62, Szeged 6726, Hungary
| | - Yue Feng
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
| | - Sanjib Jana
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Wenda Wang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
| | - Jian-Ren Shen
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, People's Republic of China
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Howe-Siang Tan
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Petar H Lambrev
- HUN-REN Biological Research Centre, Szeged, Temesvári körút 62, Szeged 6726, Hungary
| |
Collapse
|
7
|
Debus RJ, Oyala PH. Independent Mutation of Two Bridging Carboxylate Ligands Stabilizes Alternate Conformers of the Photosynthetic O 2-Evolving Mn 4CaO 5 Cluster in Photosystem II. J Phys Chem B 2024; 128:3870-3884. [PMID: 38602496 DOI: 10.1021/acs.jpcb.4c00829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
The O2-evolving Mn4CaO5 cluster in photosystem II is ligated by six carboxylate residues. One of these is D170 of the D1 subunit. This carboxylate bridges between one Mn ion (Mn4) and the Ca ion. A second carboxylate ligand is D342 of the D1 subunit. This carboxylate bridges between two Mn ions (Mn1 and Mn2). D170 and D342 are located on opposite sides of the Mn4CaO5 cluster. Recently, it was shown that the D170E mutation perturbs both the intricate networks of H-bonds that surround the Mn4CaO5 cluster and the equilibrium between different conformers of the cluster in two of its lower oxidation states, S1 and S2, while still supporting O2 evolution at approximately 50% the rate of the wild type. In this study, we show that the D342E mutation produces much the same alterations to the cluster's FTIR and EPR spectra as D170E, while still supporting O2 evolution at approximately 20% the rate of the wild type. Furthermore, the double mutation, D170E + D342E, behaves similarly to the two single mutations. We conclude that D342E alters the equilibrium between different conformers of the cluster in its S1 and S2 states in the same manner as D170E and perturbs the H-bond networks in a similar fashion. This is the second identification of a Mn4CaO5 metal ligand whose mutation influences the equilibrium between the different conformers of the S1 and S2 states without eliminating O2 evolution. This finding has implications for our understanding of the mechanism of O2 formation in terms of catalytically active/inactive conformations of the Mn4CaO5 cluster in its lower oxidation states.
Collapse
Affiliation(s)
- Richard J Debus
- Department of Biochemistry, University of California at Riverside, Riverside, California 92521, United States
| | - Paul H Oyala
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91106, United States
| |
Collapse
|
8
|
Marcolin G, Tumbarello F, Fresch E, Agostini A, Büchel C, Carbonera D, Collini E. Two-Dimensional Electronic Spectroscopy Characterization of Fucoxanthin-Chlorophyll Protein Reveals Excitonic Carotenoid-Chlorophyll Interactions. J Phys Chem Lett 2024; 15:2392-2399. [PMID: 38394035 DOI: 10.1021/acs.jpclett.3c03609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
Fucoxanthin Chlorophyll Protein (FCP) is a Light Harvesting Complex found in diatoms and brown algae. It is particularly interesting for its efficiency in capturing the blue-green part of the light spectrum due to the presence of specific chromophores (fucoxanthin, chlorophyll a, and chlorophyll c). Recently, the crystallographic structure of FCP was solved, revealing the 3D arrangement of the pigments in the protein scaffold. While this information is helpful for interpreting the spectroscopic features of FCP, it has also raised new questions about the potential interactions between fucoxanthin and chlorophyll c. These interactions were suggested by their spatial closeness but have never been experimentally observed. To investigate this possible interaction mechanism, in this work, two-dimensional electronic spectroscopy (2DES) has been applied to study the ultrafast relaxation dynamics of FCP. The experiments captured an instantaneous delocalization of the excitation among fucoxanthin and chlorophyll c, suggesting the presence of a non-negligible coupling between the chromophores.
Collapse
Affiliation(s)
- Giampaolo Marcolin
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
| | - Francesco Tumbarello
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
| | - Elisa Fresch
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
| | - Alessandro Agostini
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
| | - Claudia Büchel
- Institut für Molekulare Biowissenschaften, Goethe Universität Frankfurt, Max-von-Laue-Straβe 9, 60438 Frankfurt, Germany
| | - Donatella Carbonera
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
| | - Elisabetta Collini
- Department of Chemical Sciences, University of Padova, Via Marzolo 1, I-35131 Padova, Italy
| |
Collapse
|
9
|
Maity S, Daskalakis V, Jansen TLC, Kleinekathöfer U. Electric Field Susceptibility of Chlorophyll c Leads to Unexpected Excitation Dynamics in the Major Light-Harvesting Complex of Diatoms. J Phys Chem Lett 2024; 15:2499-2510. [PMID: 38410961 PMCID: PMC10926154 DOI: 10.1021/acs.jpclett.3c03241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 02/04/2024] [Accepted: 02/12/2024] [Indexed: 02/28/2024]
Abstract
Diatoms are one of the most abundant photosynthetic organisms on earth and contribute largely to atmospheric oxygen production. They contain fucoxanthin and chlorophyll-a/c binding proteins (FCPs) as light-harvesting complexes with a remarkable adaptation to the fluctuating light on ocean surfaces. To understand the basis of the photosynthetic process in diatoms, the excitation energy funneling within FCPs must be probed. A state-of-the-art multiscale analysis within a quantum mechanics/molecular mechanics framework has been employed. To this end, the chlorophyll (Chl) excitation energies within the FCP complex from the diatom Phaeodactylum tricornutum have been determined. The Chl-c excitation energies were found to be 5-fold more susceptible to electric fields than those of Chl-a pigments and thus are significantly lower in FCP than in organic solvents. This finding challenges the general belief that the excitation energy of Chl-c is always higher than that of Chl-a in FCP proteins and reveals that Chl-c molecules are much more sensitive to electric fields within protein scaffolds than in Chl-a pigments. The analysis of the linear absorption spectrum and the two-dimensional electronic spectra of the FCP complex strongly supports these findings and allows us to study the excitation transfer within the FCP complex.
Collapse
Affiliation(s)
- Sayan Maity
- School
of Science, Constructor University, Campus Ring 1, 28759 Bremen, Germany
| | - Vangelis Daskalakis
- Department
of Chemical Engineering, School of Engineering,
University of Patras, Patras 26504, Greece
| | - Thomas L. C. Jansen
- Zernike
Institute for Advanced Materials, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands
| | | |
Collapse
|