1
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Kaur D, Reiss K, Wang J, Batista VS, Brudvig GW, Gunner MR. Occupancy Analysis of Water Molecules inside Channels within 25 Å Radius of the Oxygen-Evolving Center of Photosystem II in Molecular Dynamics Simulations. J Phys Chem B 2024; 128:2236-2248. [PMID: 38377592 DOI: 10.1021/acs.jpcb.3c05367] [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: 02/22/2024]
Abstract
At room temperature and neutral pH, the oxygen-evolving center (OEC) of photosystem II (PSII) catalyzes water oxidation. During this process, oxygen is released from the OEC, while substrate waters are delivered to the OEC and protons are passed from the OEC to the lumen through water channels known as the narrow or the O4 channel, broad or the Cl1 channel, and large or the O1 channel. Protein residues lining the surfaces of these channels play a critical role in stabilizing the hydrogen-bonding networks that assist in the process. We carried out an occupancy analysis to better understand the structural and possible substrate water dynamics in full PSII monomer molecular dynamics (MD) trajectories in both the S1 and S2 states. We find that the equilibrated positions of water molecules derived from MD-derived electron density maps largely match the experimentally observed positions in crystallography. Furthermore, the occupancy reduction in MD simulations of some water molecules inside the single-filed narrow channel also correlates well with the crystallographic data during a structural transition when the S1 state of the OEC advances to the S2 state. The overall reduced occupancies of water molecules are the source of their "vacancy-hopping" dynamic nature inside these channels, unlike water molecules inside an ice lattice where all water molecules have a fixed unit occupancy. We propose on the basis of findings in our structural and molecular dynamics analysis that the water molecule occupying a pocket formed by D1-D61, D1-S169, and O4 of the OEC could be the last steppingstone to enter into the OEC and that the broad channel may be favored for proton transfer.
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Affiliation(s)
- Divya Kaur
- Department of Chemistry, Brock University, 500 Glenridge Avenue, St. Catharines L2S 3A1, Ontario, Canada
| | - Krystle Reiss
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520-8114, United States
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - M R Gunner
- Department of Physics, City College of New York New York, New York 10031, United States
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2
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Saito M, Saito K, Ishikita H. Structural and energetic insights into Mn-to-Fe substitution in the oxygen-evolving complex. iScience 2023; 26:107352. [PMID: 37520740 PMCID: PMC10382916 DOI: 10.1016/j.isci.2023.107352] [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: 03/01/2023] [Revised: 06/21/2023] [Accepted: 07/07/2023] [Indexed: 08/01/2023] Open
Abstract
Manganese (Mn) serves as the catalytic center for water splitting in photosystem II (PSII), despite the abundance of iron (Fe) on earth. As a first step toward why Mn and not Fe is employed by Nature in the water oxidation catalyst, we investigated the Fe4CaO5 cluster in the PSII protein environment using a quantum mechanical/molecular mechanical (QM/MM) approach, assuming an equivalence between Mn(III/IV) and Fe(II/III). Substituting Mn with Fe resulted in the protonation of μ-oxo bridges at sites O2 and O3 by Arg357 and D1-His337, respectively. While the Mn4CaO5 cluster exhibits distinct open- and closed-cubane S2 conformations, the Fe4CaO5 cluster lacks this variability due to an equal spin distribution over sites Fe1 and Fe4. The absence of a low-barrier H-bond between a ligand water molecule (W1) and D1-Asp61 in the Fe4CaO5 cluster may underlie its incapability for ligand water deprotonation, highlighting the relevance of Mn in natural water splitting.
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Affiliation(s)
- Masahiro Saito
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Keisuke Saito
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Hiroshi Ishikita
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
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3
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Saito K, Mino H, Nishio S, Ishikita H. Protonation structure of the closed-cubane conformation of the O 2-evolving complex in photosystem II. PNAS NEXUS 2022; 1:pgac221. [PMID: 36712340 PMCID: PMC9802176 DOI: 10.1093/pnasnexus/pgac221] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 09/27/2022] [Indexed: 11/17/2022]
Abstract
In photosystem II (PSII), one-electron oxidation of the most stable state of the oxygen-evolving Mn4CaO5 cluster (S1) leads to the S2 state formation, Mn1(III)Mn2(IV)Mn3(IV)Mn4(IV) (open-cubane S2) or Mn1(IV)Mn2(IV)Mn3(IV)Mn4(III) (closed-cubane S2). In electron paramagnetic resonance (EPR) spectroscopy, the g = 4.1 signal is not observed in cyanobacterial PSII but in plant PSII, whereas the g = 4.8 signal is observed in cyanobacterial PSII and extrinsic-subunit-depleted plant PSII. Here, we investigated the closed-cubane S2 conformation, a candidate for a higher spin configuration that accounts for g > 4.1 EPR signal, considering all pairwise exchange couplings in the PSII protein environment (i.e. instead of considering only a single exchange coupling between the [Mn3(CaO4)] cubane region and the dangling Mn4 site). Only when a ligand water molecule that forms an H-bond with D1-Asp61 (W1) is deprotonated at dangling Mn4(IV), the g = 4.1 EPR spectra can be reproduced using the cyanobacterial PSII crystal structure. The closed-cubane S2 is less stable than the open-cubane S2 in cyanobacterial PSII, which may explain why the g = 4.1 EPR signal is absent in cyanobacterial PSII.
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Affiliation(s)
| | - Hiroyuki Mino
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Shunya Nishio
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
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4
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Bigness A, Vaddypally S, Zdilla MJ, Mendoza-Cortes JL. Ubiquity of cubanes in bioinorganic relevant compounds. Coord Chem Rev 2022. [DOI: 10.1016/j.ccr.2021.214168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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5
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Mandal M, Saito K, Ishikita H. Requirement of Chloride for the Downhill Electron Transfer Pathway from the Water-Splitting Center in Natural Photosynthesis. J Phys Chem B 2021; 126:123-131. [PMID: 34955014 DOI: 10.1021/acs.jpcb.1c09176] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In photosystem II (PSII), Cl- is a prerequisite for the second flash-induced oxidation of the Mn4CaO5 cluster (the S2 to S3 transition). We report proton transfer from the substrate water molecule via D1-Asp61 and electron transfer via redox-active D1-Tyr161 (TyrZ) to the chlorophyll pair in Cl--depleted PSII using a quantum mechanical/molecular mechanical approach. The low-barrier H-bond formation between the substrate water molecule and D1-Asp61 remained unaffected upon the depletion of Cl-. However, the binding site, D2-Lys317, formed a salt bridge with D1-Asp61, leading to the inhibition of the subsequent proton transfer. Remarkably, the redox potential (Em) of S2/S3 increased significantly, making electron transfer from S2 to TyrZ energetically uphill, as observed in Ca2+-depleted PSII. The uphill electron transfer pathway was induced by the significant increase in Em(S2/S3) caused by the loss of charge compensation for D2-Lys317 upon the depletion of Cl-, whereas it was induced by the significant decrease in Em(TyrZ) caused by the rearrangement of the water molecules at the Ca2+ binding moiety upon the depletion of Ca2+.
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Affiliation(s)
- Manoj Mandal
- Department of Chemical, Biological & Macro-Molecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata, West Bengal 700106, India
| | - Keisuke Saito
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.,Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi Ishikita
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.,Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
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6
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Kuroda H, Kawashima K, Ueda K, Ikeda T, Saito K, Ninomiya R, Hida C, Takahashi Y, Ishikita H. Proton transfer pathway from the oxygen-evolving complex in photosystem II substantiated by extensive mutagenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148329. [PMID: 33069681 DOI: 10.1016/j.bbabio.2020.148329] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/07/2020] [Accepted: 10/13/2020] [Indexed: 12/11/2022]
Abstract
We report a structure-based biological approach to identify the proton-transfer pathway in photosystem II. First, molecular dynamics (MD) simulations were conducted to analyze the H-bond network that may serve as a Grotthuss-like proton conduit. MD simulations show that D1-Asp61, the H-bond acceptor of H2O at the Mn4CaO5 cluster (W1), forms an H-bond via one water molecule with D1-Glu65 but not with D2-Glu312. Then, D1-Asp61, D1-Glu65, D2-Glu312, and the adjacent residues, D1-Arg334, D2-Glu302, and D2-Glu323, were thoroughly mutated to the other 19 residues, i.e., 114 Chlamydomonas chloroplast mutant cells were generated. Mutation of D1-Asp61 was most crucial. Only the D61E and D61C cells grew photoautotrophically and exhibit O2-evolving activity. Mutations of D2-Glu312 were less crucial to photosynthetic growth than mutations of D1-Glu65. Quantum mechanical/molecular mechanical calculations indicated that in the PSII crystal structure, the proton is predominantly localized at D1-Glu65 along the H-bond with D2-Glu312, i.e., pKa(D1-Glu65) > pKa(D2-Glu312). The potential-energy profile shows that the release of the proton from D1-Glu65 leads to the formation of the two short H-bonds between D1-Asp61 and D1-Glu65, which facilitates downhill proton transfer along the Grotthuss-like proton conduit in the S2 to S3 transition. It seems possible that D1-Glu65 is involved in the dominant pathway that proceeds from W1 via D1-Asp61 toward the thylakoid lumen, whereas D2-Glu312 and D1-Arg334 may be involved in alternative pathways in some mutants.
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Affiliation(s)
- Hiroshi Kuroda
- Research Institute for Interdisciplinary Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Keisuke Kawashima
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan
| | - Kazuyo Ueda
- Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Takuya Ikeda
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan
| | - Keisuke Saito
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan; Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Ryo Ninomiya
- Department of Biology, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Chisato Hida
- Department of Biology, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Yuichiro Takahashi
- Research Institute for Interdisciplinary Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.
| | - Hiroshi Ishikita
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan; Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
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7
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Saito K, Mandal M, Ishikita H. Energetics of Ionized Water Molecules in the H-Bond Network near the Ca2+ and Cl– Binding Sites in Photosystem II. Biochemistry 2020; 59:3216-3224. [DOI: 10.1021/acs.biochem.0c00177] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Keisuke Saito
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Manoj Mandal
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Hiroshi Ishikita
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
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8
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Mandal M, Kawashima K, Saito K, Ishikita H. Redox Potential of the Oxygen-Evolving Complex in the Electron Transfer Cascade of Photosystem II. J Phys Chem Lett 2020; 11:249-255. [PMID: 31729876 DOI: 10.1021/acs.jpclett.9b02831] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In photosystem II (PSII), water oxidation occurs in the Mn4CaO5 cluster with the release of electrons via the redox-active tyrosine (TyrZ) to the reaction-center chlorophylls (PD1/PD2). Using a quantum mechanical/molecular mechanical approach, we report the redox potentials (Em) of these cofactors in the PSII protein environment. The Em values suggest that the Mn4CaO5 cluster, TyrZ, and PD1/PD2 form a downhill electron transfer pathway. Em for the first oxidation step, Em(S0/S1), is uniquely low (730 mV) and is ∼100 mV lower than that for the second oxidation step, Em(S1/S2) (830 mV) only when the O4 site of the Mn4CaO5 cluster is protonated in S0. The O4-water chain, which directly forms a low-barrier H-bond with the Mn4CaO5 cluster and mediates proton-coupled electron transfer in the S0 to S1 transition, explains why the second lowest oxidation state, S1, is the most stable and S0 is converted to S1 even in the dark.
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Affiliation(s)
- Manoj Mandal
- Research Center for Advanced Science and Technology , The University of Tokyo , 4-6-1 Komaba , Meguro-ku, Tokyo 153-8904 , Japan
| | - Keisuke Kawashima
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-8654 , Japan
| | - Keisuke Saito
- Research Center for Advanced Science and Technology , The University of Tokyo , 4-6-1 Komaba , Meguro-ku, Tokyo 153-8904 , Japan
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-8654 , Japan
| | - Hiroshi Ishikita
- Research Center for Advanced Science and Technology , The University of Tokyo , 4-6-1 Komaba , Meguro-ku, Tokyo 153-8904 , Japan
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-8654 , Japan
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9
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Shamsipur M, Pashabadi A. Latest advances in PSII features and mechanism of water oxidation. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Chu J, Zhu F, Chen X, Liang H, Wang R, Wang X, Huang X. Effects of cadmium on photosynthesis of Schima superba young plant detected by chlorophyll fluorescence. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:10679-10687. [PMID: 29392606 DOI: 10.1007/s11356-018-1294-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
Contamination by heavy metals has become a serious environmental pollution issue today due to its potential threat to plant, wildlife, and human health. Photosynthesis, a process in which light energy is used to produce sugar and other organic compounds, is sensitive to heavy metals. In the present study, the response of photosynthetic process and carbon assimilation of Schima superba was investigated under cadmium (Cd) stress. Three Cd concentrations (0, 300, and 600 mg kg-1) were used designated as control (CK), low Cd (L1), and high Cd treatment (L2) of plants. Results showed that photosystem II (PSII) acceptor and donor side electron transport were more easily blocked in treatment compared to control, and L2 have more significant changes than L1. A substantial decrease of 820 nm reflection curve absorption was observed both in L1 and L2 treatments. Special energy fluxes showed significant difference between the control group and the treated group, which indicated that low concentration Cd stress can cause decrease in quantum yield of PSII in plants studied. Non-stomatal factors resulted in a decrease in net photosynthetic rate and a decrease in photosystem activity. Our results suggested that Cd can damage structure and function of the photosynthesis of S. superba young plants.
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Affiliation(s)
- Jingjing Chu
- National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, People's Republic of China
| | - Fan Zhu
- National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, People's Republic of China.
| | - Xiaoyong Chen
- National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, People's Republic of China
- College of Arts and Sciences, Governors State University, Chicago, IL, 60466, USA
| | - Huizi Liang
- National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, People's Republic of China
| | - Renjie Wang
- National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, People's Republic of China
| | - Xuxu Wang
- National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, People's Republic of China
| | - Xinhao Huang
- National Engineering Laboratory for Applied Forest Ecological Technology in Southern China, College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, 410004, People's Republic of China
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11
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Sakashita N, Watanabe HC, Ikeda T, Saito K, Ishikita H. Origins of Water Molecules in the Photosystem II Crystal Structure. Biochemistry 2017; 56:3049-3057. [DOI: 10.1021/acs.biochem.7b00220] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Naoki Sakashita
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi C. Watanabe
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Takuya Ikeda
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Keisuke Saito
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Hiroshi Ishikita
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
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12
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Kim CJ, Debus RJ. Evidence from FTIR Difference Spectroscopy That a Substrate H2O Molecule for O2 Formation in Photosystem II Is Provided by the Ca Ion of the Catalytic Mn4CaO5 Cluster. Biochemistry 2017; 56:2558-2570. [DOI: 10.1021/acs.biochem.6b01278] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Christopher J. Kim
- Department of Biochemistry, University of California, Riverside, California 92521, United States
| | - Richard J. Debus
- Department of Biochemistry, University of California, Riverside, California 92521, United States
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13
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Zhang Z, Coats KL, Chen Z, Hubin TJ, Yin G. Influence of Calcium(II) and Chloride on the Oxidative Reactivity of a Manganese(II) Complex of a Cross-Bridged Cyclen Ligand. Inorg Chem 2014; 53:11937-47. [DOI: 10.1021/ic501342c] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Zhan Zhang
- Key
Laboratory for Large-Format Battery Materials and System, Ministry
of Education, School of Chemistry and Chemical Engineering, Hubei
Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Katherine L. Coats
- Department
of Chemistry and Physics, Southwestern Oklahoma State University, 100
Campus Drive, Weatherford, Oklahoma 73096, United States
| | - Zhuqi Chen
- Key
Laboratory for Large-Format Battery Materials and System, Ministry
of Education, School of Chemistry and Chemical Engineering, Hubei
Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Timothy J. Hubin
- Department
of Chemistry and Physics, Southwestern Oklahoma State University, 100
Campus Drive, Weatherford, Oklahoma 73096, United States
| | - Guochuan Yin
- Key
Laboratory for Large-Format Battery Materials and System, Ministry
of Education, School of Chemistry and Chemical Engineering, Hubei
Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
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14
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Wang L, Zhang C, Zhao J. Location and function of the high-affinity chloride in the oxygen-evolving complex – Implications from comparing studies on Cl−/Br−/I−-substituted photosystem II prepared using two different methods. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2014; 138:249-55. [DOI: 10.1016/j.jphotobiol.2014.05.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 05/22/2014] [Accepted: 05/26/2014] [Indexed: 11/17/2022]
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15
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Barber J. Photosystem II: Its function, structure, and implications for artificial photosynthesis. BIOCHEMISTRY (MOSCOW) 2014; 79:185-96. [DOI: 10.1134/s0006297914030031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Saito K, Ishikita H. Influence of the Ca 2+ ion on the Mn 4 Ca conformation and the H-bond network arrangement in Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:159-66. [DOI: 10.1016/j.bbabio.2013.09.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 09/19/2013] [Accepted: 09/24/2013] [Indexed: 01/06/2023]
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17
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Suzuki H, Yu J, Kobayashi T, Nakanishi H, Nixon PJ, Noguchi T. Functional roles of D2-Lys317 and the interacting chloride ion in the water oxidation reaction of photosystem II as revealed by fourier transform infrared analysis. Biochemistry 2013; 52:4748-57. [PMID: 23786399 PMCID: PMC3777104 DOI: 10.1021/bi301699h] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photosynthetic water oxidation in plants and cyanobacteria is catalyzed by a Mn4CaO5 cluster within the photosystem II (PSII) protein complex. Two Cl(-) ions bound near the Mn4CaO5 cluster act as indispensable cofactors, but their functional roles remain to be clarified. We have investigated the role of the Cl(-) ion interacting with D2-K317 (designated Cl-1) by Fourier transform infrared spectroscopy (FTIR) analysis of the D2-K317R mutant of Synechocystis sp. PCC 6803 in combination with Cl(-)/NO3(-) replacement. The D2-K317R mutation perturbed the bands in the regions of the COO(-) stretching and backbone amide vibrations in the FTIR difference spectrum upon the S1 → S2 transition. In addition, this mutation altered the (15)N isotope-edited NO3(-) bands in the spectrum of NO3(-)-treated PSII. These results provide the first experimental evidence that the Cl-1 site is coupled with the Mn4CaO5 cluster and its interaction is affected by the S1 → S2 transition. It was also shown that a negative band at 1748 cm(-1) arising from COOH group(s) was altered to a positive intensity by the D2-K317R mutation as well as by NO3(-) treatment, suggesting that the Cl-1 site affects the pKa of COOH/COO(-) group(s) near the Mn4CaO5 cluster in a common hydrogen bond network. Together with the observation that the efficiency of the S3 → S0 transition significantly decreased in the core complexes of D2-K317R upon moderate dehydration, it is suggested that D2-K317 and Cl-1 are involved in a proton transfer pathway from the Mn4CaO5 cluster to the lumen, which functions in the S3 → S0 transition.
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Affiliation(s)
- Hiroyuki Suzuki
- Division of Material Science, Graduate School of Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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Abstract
Using quantum mechanics/molecular mechanics calculations and the 1.9-Å crystal structure of Photosystem II [Umena Y, Kawakami K, Shen J-R, Kamiya N (2011) Nature 473(7345):55-60], we investigated the H-bonding environment of the redox-active tyrosine D (TyrD) and obtained insights that help explain its slow redox kinetics and the stability of TyrD(•). The water molecule distal to TyrD, located ~4 Å away from the phenolic O of TyrD, corresponds to the presence of the tyrosyl radical state. The water molecule proximal to TyrD, in H-bonding distance to the phenolic O of TyrD, corresponds to the presence of the unoxidized tyrosine. The H(+) released on oxidation of TyrD is transferred to the proximal water, which shifts to the distal position, triggering a concerted proton transfer pathway involving D2-Arg180 and a series of waters, through which the proton reaches the aqueous phase at D2-His61. The water movement linked to the ejection of the proton from the hydrophobic environment near TyrD makes oxidation slow and quasiirreversible, explaining the great stability of the TyrD(•). A symmetry-related proton pathway associated with tyrosine Z is pointed out, and this is associated with one of the Cl(-) sites. This may represent a proton pathway functional in the water oxidation cycle.
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Boussac A, Ishida N, Sugiura M, Rappaport F. Probing the role of chloride in Photosystem II from Thermosynechococcus elongatus by exchanging chloride for iodide. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:802-10. [DOI: 10.1016/j.bbabio.2012.02.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 02/21/2012] [Accepted: 02/24/2012] [Indexed: 11/29/2022]
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20
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Ren Y, Zhang C, Zhao J. Substitution of chloride by bromide modifies the low-temperature tyrosine Z oxidation in active photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1421-7. [PMID: 20206122 DOI: 10.1016/j.bbabio.2010.02.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2009] [Revised: 01/29/2010] [Accepted: 02/23/2010] [Indexed: 11/19/2022]
Abstract
Chloride is an essential cofactor for photosynthetic water oxidation. However, its location and functional roles in active photosystem II are still a matter of debate. We have investigated this issue by studying the effects of Cl- replacement by Br- in active PSII. In Br- substituted samples, Cl- is effectively replaced by Br- in the presence of 1.2 M NaBr under room light with protection of anaerobic atmosphere followed by dialysis. The following results have been obtained. i) The oxygen-evolving activities of the Br--PSII samples are significantly lower than that of the Cl--PSII samples; ii) The same S2 multiline EPR signals are observed in both Br- and Cl--PSII samples; iii) The amplitudes of the visible light induced S1TyrZ* and S2TyrZ* EPR signals are significantly decreased after Br- substitution; the S1TyrZ* EPR signal is up-shifted about 8G, whereas the S2TyrZ* signal is down-shifted about 12 G after Br- substitution. These results imply that the redox properties of TyrZ and spin interactions between TyrZ* and Mn-cluster could be significantly modified due to Br- substitution. It is suggested that Cl-/Br- probably coordinates to the Ca2+ ion of the Mn-cluster in active photosystem II.
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Affiliation(s)
- Yanan Ren
- Laboratory of Photochemistry, Beijing National Laboratory of Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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21
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Gauthier A, Carpentier R. Disorganization of the Mn4Ca complex of photosystem II by ruthenium red: a thermoluminescence study. LUMINESCENCE 2009; 24:108-14. [DOI: 10.1002/bio.1082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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22
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Semin BK, Davletshina LN, Ivanov II, Rubin AB, Seibert M. Decoupling of the processes of molecular oxygen synthesis and electron transport in Ca2+-depleted PSII membranes. PHOTOSYNTHESIS RESEARCH 2008; 98:235-249. [PMID: 18814052 DOI: 10.1007/s11120-008-9347-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Accepted: 07/30/2008] [Indexed: 05/26/2023]
Abstract
Extraction of Ca(2+) from the O(2)-evolving complex (OEC) of photosystem II (PSII) membranes with 2 M NaCl in the light (PSII(-Ca/NaCl)) results in 90% inhibition of the O(2)-evolution reaction. However, electron transfer from the donor to acceptor side of PSII, measured as the reduction of the exogenous acceptor 2,6-dichlorophenolindophenol (DCIP) under continuous light, is inhibited by only 30%. Thus, calcium extraction from the OEC inhibits the synthesis of molecular O(2) but not the oxidation of a substrate we term X, the source of electrons for DCIP reduction. The presence of electron transfer across PSII(-Ca/NaCl) membranes was demonstrated using fluorescence induction kinetics, a method that does not require an artificial acceptor. The calcium chelator, EGTA (5 mM), when added to PSII(-Ca/NaCl) membranes, does not affect the inhibition of O(2) evolution by NaCl but does inhibit DCIP reduction up to 92% (the reason why electron transport in Ca(2+)-depleted materials has not been noticed before). Another chelator, sodium citrate (citrate/low pH method of calcium extraction), also inhibits both O(2) evolution and DCIP reduction. The role of all buffer components (including bicarbonate and sucrose) as possible sources of electrons for PSII(-Ca/NaCl) membranes was investigated, but only the absence of chloride anions strongly inhibited the rate of DCIP reduction. Substitution of other anions for chloride indicates that Cl(-) serves its well-known role as an OEC cofactor, but it is not substrate X. Multiple turnover flash experiments have shown a period of four oscillations of the fluorescence yield (both the maximum level, F(max), and the fluorescence level measured 50 s after an actinic flash in the presence of DCMU) in native PSII membranes, reflecting the normal function of the OEC, but the absence of oscillations in PSII(-Ca/NaCl) samples. Thus, PSII(-Ca/NaCl) samples do not evolve O(2) but do transfer electrons from the donor to acceptor sides and exhibit a disrupted S-state cycle. We explain these results as follows. In Ca(2+)-depleted PSII membranes, obtained without chelators, the oxidation of the OEC stops after the absorption of three quanta of light (from the S1 state), which should convert the native OEC to the S4 state. An one-electron oxidation of the water molecule bound to the Mn cluster then occurs (the second substrate water molecule is absent due to the absence of calcium), and the OEC returns to the S3 state. The appearance of a sub-cycle within the S-state cycle between S3-like and S4-like states supplies electrons (substrate X is postulated to be OH(-)), explains the absence of O(2) production, and results in the absence of a period of four oscillation of the normal functional parameters, such as the fluorescence yield or the EPR signal from S2. Chloride anions probably keep the redox potential of the Mn cluster low enough for its oxidation by Y(Z)(*).
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Affiliation(s)
- Boris K Semin
- Department of Biophysics, Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
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23
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Ishida N, Sugiura M, Rappaport F, Lai TL, Rutherford AW, Boussac A. Biosynthetic Exchange of Bromide for Chloride and Strontium for Calcium in the Photosystem II Oxygen-evolving Enzymes. J Biol Chem 2008; 283:13330-40. [DOI: 10.1074/jbc.m710583200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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24
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Abstract
Photosynthetic water oxidation is catalyzed by a unique Mn(4)Ca cluster in Photosystem II. The ligation environment of the Mn(4)Ca cluster optimizes the cluster's reactivity at each step in the catalytic cycle and minimizes the release of toxic, partly oxidized intermediates. However, our understanding of the cluster's ligation environment remains incomplete. Although the recent X-ray crystallographic structural models have provided great insight and are consistent with most conclusions of earlier site-directed mutagenesis studies, the ligation environments of the Mn(4)Ca cluster in the two available structural models differ in important respects. Furthermore, while these structural models and the earlier mutagenesis studies agree on the identity of most of the Mn(4)Ca cluster's amino acid ligands, they disagree on the identity of others. This review describes mutant characterizations that have been undertaken to probe the ligation environment of the Mn(4)Ca cluster, some of which have been inspired by the recent X-ray crystallographic structural models. Many of these characterizations have involved Fourier Transform Infrared (FTIR) difference spectroscopy because of the extreme sensitivity of this form of spectroscopy to the dynamic structural changes that occur during an enzyme's catalytic cycle.
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Affiliation(s)
- Richard J. Debus
- Department of Biochemistry, University of California at Riverside, Riverside, CA 92521-0129
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25
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Semin BK, Davletshina LN, Bulychev AA, Ivanov II, Seibert M, Rubin AB. Effect of calcium chelators on the formation and oxidation of the slowly relaxing reduced plastoquinone pool in calcium-depleted PSII membranes. Investigation of the F0 yield. BIOCHEMISTRY (MOSCOW) 2007; 72:1205-15. [DOI: 10.1134/s0006297907110065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Lu YK, Stemler AJ. Differing responses of the two forms of photosystem II carbonic anhydrase to chloride, cations, and pH. BIOCHIMICA ET BIOPHYSICA ACTA 2007; 1767:633-8. [PMID: 17320812 DOI: 10.1016/j.bbabio.2006.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 11/25/2006] [Accepted: 12/14/2006] [Indexed: 10/23/2022]
Abstract
The effects of Cl(-), Mn(2+), Ca(2+), and pH on extrinsic and intrinsic photosystem II carbonic anhydrase activity were compared. Under the conditions of our in vitro experiments, extrinsic CA activity, located on the OEC33 protein, was optimum at about 30 mM Cl(-), and strongly inhibited above this concentration. This enzyme is activated by Mn(2+) and stimulated somewhat by Ca(2+). The OEC33 showed dehydration activity that is optimum at pH 6 or below. In contrast, intrinsic CA activity found in the PSII complex after removal of extrinsic proteins was stimulated by Cl(-) up to 0.4 M. Ca(2+) appears to be the required cofactor, which implies that the location of the intrinsic CA activity is in the immediate vicinity of the CaMn(4) complex. Up to now, intrinsic CA has shown only hydration activity that is nearly pH independent.
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Affiliation(s)
- Yih-Kuang Lu
- Section of Plant Biology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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27
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Affiliation(s)
- James P McEvoy
- Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, USA
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28
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Kargul J, Maghlaoui K, Murray JW, Deak Z, Boussac A, Rutherford AW, Vass I, Barber J. Purification, crystallization and X-ray diffraction analyses of the T. elongatus PSII core dimer with strontium replacing calcium in the oxygen-evolving complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:404-13. [PMID: 17321490 DOI: 10.1016/j.bbabio.2007.01.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2006] [Revised: 01/05/2007] [Accepted: 01/09/2007] [Indexed: 11/17/2022]
Abstract
The core complex of photosystem II (PSII) was purified from thermophilic cyanobacterium Thermosynechococcus elongatus grown in Sr(2+)-containing and Ca(2+)-free medium. Functional in vivo incorporation of Sr(2+) into the oxygen-evolving complex (OEC) was confirmed by EPR analysis of the isolated and highly purified SrPSII complex in agreement with the previous study of Boussac et al. [J. Biol. Chem. 279 (2004) 22809-22819]. Three-dimensional crystals of SrPSII complex were obtained which diffracted to 3.9 A and belonged to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions of a=133.6 A, b=236.6 A, c=307.8 A. Anomalous diffraction data collected at the Sr K-X-ray absorption edge identified a novel Sr(2+)-binding site which, within the resolution of these data (6.5 A), is consistent with the positioning of Ca(2+) in the recent crystallographic models of PSII [Ferreira et al. Science 303 (2004) 1831-1838, Loll et al. Nature 438 (2005) 1040-1044]. Fluorescence measurements on SrPSII crystals confirmed that crystallized SrPSII was active in transferring electrons from the OEC to the acceptor site of the reaction centre. However, SrPSII showed altered functional properties of its modified OEC in comparison with that of the CaPSII counterpart: slowdown of the Q(A)-to-Q(B) electron transfer and stabilized S(2)Q(A)(-) charge recombination.
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Affiliation(s)
- Joanna Kargul
- Wolfson Laboratories, Division of Molecular Biosciences, Faculty of Natural Sciences, Imperial College London, London, UK
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29
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Du JT, Li YM, Wei W, Wu GS, Zhao YF, Kanazawa K, Nemoto T, Nakanishi H. Low-barrier hydrogen bond between phosphate and the amide group in phosphopeptide. J Am Chem Soc 2006; 127:16350-1. [PMID: 16305194 DOI: 10.1021/ja054568p] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As the conversion between the monoionic (1) and diionic (2) form of the phosphate occurs, the phosphorylated peptides or proteins can not only cause the formation of a hydrogen bond between the phosphate group and the amide group but also change the strength of the hydrogen bond to form low-barrier hydrogen bonds (LBHBs). This reversible protonation of the phosphate group, which changes both the electrostatic properties of the phosphate group and the strength of the hydrogen bond, provides a possible mechanism in regulating protein function.
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Affiliation(s)
- Jin-Tang Du
- Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, PR China
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30
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Barry BA, Hicks C, De Riso A, Jenson DL. Calcium ligation in photosystem II under inhibiting conditions. Biophys J 2005; 89:393-401. [PMID: 15985425 PMCID: PMC1366539 DOI: 10.1529/biophysj.105.059667] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In oxygenic photosynthesis, PSII carries out the oxidation of water and reduction of plastoquinone. The product of water oxidation is molecular oxygen. The water splitting complex is located on the lumenal side of the PSII reaction center and contains manganese, calcium, and chloride. Four sequential photooxidation reactions are required to generate oxygen from water; the five sequentially oxidized forms of the water splitting complex are known as the Sn states, where n refers to the number of oxidizing equivalents stored. Calcium plays a role in water oxidation; removal of calcium is associated with an inhibition of the S state cycle. Although calcium can be replaced by other cations in vitro, only strontium maintains activity, and the steady-state rate of oxygen evolution is decreased in strontium-reconstituted PSII. In this article, we study the role of calcium in PSII that is limited in water content. We report that strontium substitution or 18OH2 exchange causes conformational changes in the calcium ligation shell. The conformational change is detected because of a perturbation to calcium ligation during the S1 to S2 and S2 to S3 transition under water-limited conditions.
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Affiliation(s)
- Bridgette A Barry
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
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31
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Jajoo A, Bharti S, Kawamori A. EPR characteristics of chloride-depleted photosystem II membranes in the presence of other anions. Photochem Photobiol Sci 2005; 4:459-62. [PMID: 15920629 DOI: 10.1039/b414849e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chloride is an essential cofactor for the oxidation of water to oxygen. Anion substitution (Br(-), I(-), NO(2)(-), F(-)) in Cl(-)-depleted PS II membranes brings out significant changes in the EPR signals arising from the S(2) state and from the iron-quinone complex of PS II. On the basis of the changes observed in the S(2) state multiline signal and the Q(A)Fe(3+) EPR signal in Cl(-)-depleted PS II membranes after substituting with various anions, we report a possible binding site of anions such as chloride and bromide at the PS II donor side as well as at the acceptor side.
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Affiliation(s)
- Anjana Jajoo
- School of Life Sciences, Vigyan Bhawan Khandwa Road, Devi Ahilya Vishwavidyalaya, Indore 452 017, M.P., India.
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32
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Sigfridsson KGV, Bernát G, Mamedov F, Styring S. Molecular interference of Cd2+ with Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2004; 1659:19-31. [PMID: 15511524 DOI: 10.1016/j.bbabio.2004.07.003] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2004] [Revised: 06/23/2004] [Accepted: 07/07/2004] [Indexed: 12/31/2022]
Abstract
Many heavy metals inhibit electron transfer reactions in Photosystem II (PSII). Cd(2+) is known to exchange, with high affinity in a slow reaction, for the Ca(2+) cofactor in the Ca/Mn cluster that constitutes the oxygen-evolving center. This results in inhibition of photosynthetic oxygen evolution. There are also indications that Cd(2+) binds to other sites in PSII, potentially to proton channels in analogy to heavy metal binding in photosynthetic reaction centers from purple bacteria. In search for the effects of Cd(2+)-binding to those sites, we have studied how Cd(2+) affects electron transfer reactions in PSII after short incubation times and in sites, which interact with Cd(2+) with low affinity. Overall electron transfer and partial electron transfer were studied by a combination of EPR spectroscopy of individual redox components, flash-induced variable fluorescence and steady state oxygen evolution measurements. Several effects of Cd(2+) were observed: (i) the amplitude of the flash-induced variable fluorescence was lost indicating that electron transfer from Y(Z) to P(680)(+) was inhibited; (ii) Q(A)(-) to Q(B) electron transfer was slowed down; (iii) the S(2) state multiline EPR signal was not observable; (iv) steady state oxygen evolution was inhibited in both a high-affinity and a low-affinity site; (v) the spectral shape of the EPR signal from Q(A)(-)Fe(2+) was modified but its amplitude was not sensitive to the presence of Cd(2+). In addition, the presence of both Ca(2+) and DCMU abolished Cd(2+)-induced effects partially and in different sites. The number of sites for Cd(2+) binding and the possible nature of these sites are discussed.
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Affiliation(s)
- Kajsa G V Sigfridsson
- Department of Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00 Lund, Sweden
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33
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Boussac A, Rappaport F, Carrier P, Verbavatz JM, Gobin R, Kirilovsky D, Rutherford AW, Sugiura M. Biosynthetic Ca2+/Sr2+ Exchange in the Photosystem II Oxygen-evolving Enzyme of Thermosynechococcus elongatus. J Biol Chem 2004; 279:22809-19. [PMID: 14990562 DOI: 10.1074/jbc.m401677200] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The thermophilic cyanobacterium, Thermosynechococcus elongatus, has been grown in the presence of Sr2+ instead of Ca2+ with the aim of biosynthetically replacing the Ca2+ of the oxygen-evolving enzyme with Sr2+. Not only were the cells able to grow normally with Sr2+, they actively accumulated the ion to levels higher than those of Ca2+ in the normal cultures. A protocol was developed to purify a fully active Sr(2+)-containing photosystem II (PSII). The modified enzyme contained a normal polypeptide profile and 1 strontium/4 manganese, indicating that the normal enzyme contains 1 calcium/4 manganese. The Sr(2+)- and Ca(2+)-containing enzymes were compared using EPR spectroscopy, UV-visible absorption spectroscopy, and O2 polarography. The Ca2+/Sr2+ exchange resulted in the modification of the EPR spectrum of the manganese cluster and a slower turnover of the redox cycle (the so-called S-state cycle), resulting in diminished O2 evolution activity under continuous saturating light: all features reported previously by biochemical Ca2+/Sr2+ exchange in plant PSII. This allays doubts that these changes could be because of secondary effects induced by the biochemical treatments themselves. In addition, the Sr(2+)-containing PSII has other kinetics modifications: 1) it has an increased stability of the S3 redox state; 2) it shows an increase in the rate of electron donation from TyrD, the redox-active tyrosine of the D2 protein, to the oxygen-evolving complex in the S3-state forming S2; 3) the rate of oxidation of the S0-state to the S1-state by TyrD* is increased; and 4) the release of O2 is slowed down to an extent similar to that seen for the slowdown of the S3TyrZ* to S0TyrZ transition, consistent with the latter constituting the limiting step of the water oxidation mechanism in Sr(2+)-substituted enzyme as well as in the normal enzyme. The replacement of Ca2+ by Sr2+ appears to have multiple effects on kinetics properties of the enzyme that may be explained by S-state-dependent shifts in the redox properties of both the manganese complex and TyrZ as well as structural effects.
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Affiliation(s)
- Alain Boussac
- Service de Bioénergétique, DBJC, URA CNRS 2096, CEA Saclay, 91191 Gif sur Yvette, France.
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Stevens GB, Lukins PB. Effects of Ca2+ and EGTA on P680*+ reduction kinetics and O2 evolution of Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1605:21-34. [PMID: 12907298 DOI: 10.1016/s0005-2728(03)00061-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We report for the first time significant changes in the P680*+ reduction kinetics of Photosystem II (PS II) in which the 17 and 23 kDa extrinsic polypeptides are intact, in the presence of Ca(2+) or ethylene glycol bis (beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) which were added to vary the Ca(2+) concentration from 5 microM to 30 mM. The decrease in the extent of normal P680*+ reduction decay with lifetimes of 40-370 ns and a corresponding increase in the extent of kinetics with lifetimes of 20-220 micros was interpreted as being due to electron transfer from Y(Z) to P680*+ being replaced by slow forward conduction and by processes including P680*+/Q(A)(-) recombination. The question of whether changes in P680*+ reduction kinetics were caused by loss of Ca(2+) from PS II or by direct interaction of EGTA with PS II was addressed by lowering the free-Ca(2+) concentration of suspensions of PS II core complexes by serial dilution in the absence of EGTA. Despite a significant decrease in the rate of O(2) evolution after this treatment, only small changes in the P680*+ reduction kinetics were observed. Loss of Ca(2+) did not affect P680*+ reduction associated with electron transfer from Y(Z). Since much larger changes in the P680*+ reduction kinetics of intact PS II occurred at comparable free-Ca(2+) concentrations in the presence of EGTA, we conclude that EGTA influenced the P680*+ reduction kinetics by directly interacting with PS II rather than by lowering the free Ca(2+) concentration of the surrounding media. Notwithstanding these effects, we show that useful information about Ca(2+) binding to PS II can be obtained when direct interaction of EGTA is taken into account.
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Affiliation(s)
- Gregory B Stevens
- CSIRO Telecommunications and Industrial Physics, Bradfield Road, Lindfield, NSW 2070, Australia.
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35
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Goussias C, Boussac A, Rutherford AW. Photosystem II and photosynthetic oxidation of water: an overview. Philos Trans R Soc Lond B Biol Sci 2002; 357:1369-81; discussion 1419-20. [PMID: 12437876 PMCID: PMC1693055 DOI: 10.1098/rstb.2002.1134] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Conceptually, photosystem II, the oxygen-evolving enzyme, can be divided into two parts: the photochemical part and the catalytic part. The photochemical part contains the ultra-fast and ultra-efficient light-induced charge separation and stabilization steps that occur when light is absorbed by chlorophyll. The catalytic part, where water is oxidized, involves a cluster of Mn ions close to a redox-active tyrosine residue. Our current understanding of the catalytic mechanism is mainly based on spectroscopic studies. Here, we present an overview of the current state of knowledge of photosystem II, attempting to delineate the open questions and the directions of current research.
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Affiliation(s)
- Charilaos Goussias
- Service de Bioénergétique, URA CNRS 2096, Bat 532, CEA Saclay, 91191 Gif-sur-Yvette, France
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36
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Westphal KL, Lydakis-Simantiris N, Cukier RI, Babcock GT. Effects of Sr2+-substitution on the reduction rates of Yz* in PSII membranes--evidence for concerted hydrogen-atom transfer in oxygen evolution. Biochemistry 2000; 39:16220-9. [PMID: 11123952 DOI: 10.1021/bi0018077] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several groups have recently investigated the kinetic effects of biochemical treatments, site-directed mutagenesis, or substitution of essential cofactors on the stepwise, water-oxidizing chemistry catalyzed by Photosystem II. Consistently, these studies show evidence for a slowing of the final, oxygen-releasing step, S(3) --> S(0), of the catalytic cycle. To a degree, some of this work also shows a slowing of the earlier S-state transitions. To study these processes in more detail, we have investigated the effect of replacing Ca(2+) with Sr(2+)on the rates of the S-state transitions by using time-resolved electron paramagnetic resonance. The results show a slowdown of the last transition in the cycle, consistent with a report from Boussac et al. [Boussac, A., Sétif, P., and Rutherford, A. W. (1992) Biochemistry 31, 1224-1234], and of the earlier S-state transitions as well, which suggests that a common molecular mechanism is at work and that Sr(2+) is less effective than Ca(2+) in supporting it. While the oxidation of Y(z) by P(680)(+) has been extensively studied and can be understood within the context of nonadiabatic electron tunneling combined with rapid, non-rate-limiting proton transfer in the holo-system [Tommos, C., and Babcock, G. T. (2000) Biochim. Biophys. Acta 1458, 199], the reduction of Y(z*) by the Mn cluster cannot be described effectively by a nonadiabatic electron-transfer formalism. This indicates that this reaction is rate limited by processes other than electron tunneling. We discuss our results for Y(z*) reduction and those of others for the activation parameters (E(a), A, KIE, and rates) associated with this process, in terms of both sequential and concerted proton-coupled, electron transfer. Our analysis indicates that concerted hydrogen-atom transfer processes best explain the observed characteristics of the S-state advances.
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Affiliation(s)
- K L Westphal
- Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA
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37
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Löhr F, Mayhew SG, Rüterjans H. Detection of Scalar Couplings Across NH···OP and OH···OP Hydrogen Bonds in a Flavoprotein. J Am Chem Soc 2000. [DOI: 10.1021/ja001345k] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Frank Löhr
- Contribution from the Institut für Biophysikalische Chemie, Johann Wolfgang Goethe-Universität, Biozentrum N230, Marie Curie-Strasse 9, 60439 Frankfurt am Main, Germany, and Department of Biochemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Stephen G. Mayhew
- Contribution from the Institut für Biophysikalische Chemie, Johann Wolfgang Goethe-Universität, Biozentrum N230, Marie Curie-Strasse 9, 60439 Frankfurt am Main, Germany, and Department of Biochemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Heinz Rüterjans
- Contribution from the Institut für Biophysikalische Chemie, Johann Wolfgang Goethe-Universität, Biozentrum N230, Marie Curie-Strasse 9, 60439 Frankfurt am Main, Germany, and Department of Biochemistry, University College Dublin, Belfield, Dublin 4, Ireland
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38
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Tommos C, Babcock GT. Proton and hydrogen currents in photosynthetic water oxidation. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1458:199-219. [PMID: 10812034 DOI: 10.1016/s0005-2728(00)00069-4] [Citation(s) in RCA: 266] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The photosynthetic processes that lead to water oxidation involve an evolution in time from photon dynamics to photochemically-driven electron transfer to coupled electron/proton chemistry. The redox-active tyrosine, Y(Z), is the component at which the proton currents necessary for water oxidation are switched on. The thermodynamic and kinetic implications of this function for Y(Z) are discussed. These considerations also provide insight into the related roles of Y(Z) in preserving the high photochemical quantum efficiency in Photosystem II (PSII) and of conserving the highly oxidizing conditions generated by the photochemistry in the PSII reaction center. The oxidation of Y(Z) by P(680)(+) can be described well by a treatment that invokes proton coupling within the context of non-adiabatic electron transfer. The reduction of Y(.)(Z), however, appears to proceed by an adiabatic process that may have hydrogen-atom transfer character.
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Affiliation(s)
- C Tommos
- Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
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Dorlet P, Boussac A, Rutherford AW, Un S. Multifrequency High-Field EPR Study of the Interaction between the Tyrosyl Z Radical and the Manganese Cluster in Plant Photosystem II. J Phys Chem B 1999. [DOI: 10.1021/jp992420k] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Pierre Dorlet
- Section de Bioénergétique, Département de Biologie Cellulaire et Moléculaire, CNRS URA 2096, Bât. 532, CEA Saclay, F-91191 Gif-sur-Yvette Cedex, France
| | - Alain Boussac
- Section de Bioénergétique, Département de Biologie Cellulaire et Moléculaire, CNRS URA 2096, Bât. 532, CEA Saclay, F-91191 Gif-sur-Yvette Cedex, France
| | - A. William Rutherford
- Section de Bioénergétique, Département de Biologie Cellulaire et Moléculaire, CNRS URA 2096, Bât. 532, CEA Saclay, F-91191 Gif-sur-Yvette Cedex, France
| | - Sun Un
- Section de Bioénergétique, Département de Biologie Cellulaire et Moléculaire, CNRS URA 2096, Bât. 532, CEA Saclay, F-91191 Gif-sur-Yvette Cedex, France
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40
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Photosynthetic water oxidation: a simplex-scheme of its partial reactions. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1411:86-91. [PMID: 10216154 DOI: 10.1016/s0005-2728(99)00042-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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41
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Evidence for impaired hydrogen-bonding of tyrosine YZ in calcium-depleted photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1411:121-33. [PMID: 10216158 DOI: 10.1016/s0005-2728(99)00045-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Photosystem II (PS II) evolves oxygen from two bound water molecules in a four-stepped reaction that is driven by four quanta of light, each oxidizing the chlorophyll moiety P680 to yield P+680. When starting from its dark equilibrium (mainly state S1), the catalytic center can be clocked through its redox states (S0ellipsisS4) by a series of short flashes of light. The center involves at least a Mn4-cluster and a special tyrosine residue, named YZ, as redox cofactors plus two essential ionic cofactors, Cl- and Ca2+. Centers which have lost Ca2+ do not evolve oxygen. We investigated the stepped progression in dark-adapted PS II core particles after the removal of Ca2+. YZ was oxidized from the first flash on. The difference spectrum of YZ-->YoxZ differed from the one in competent centers, where it has been ascribed to a hydrogen-bonded tyrosinate. The rate of the electron transfer from YZ to P+680 was slowed down by three orders of magnitude and its kinetic isotope effect rose up from 1.1 to 2.5. Proton release into the bulk was now a prerequisite for the electron transfer from YZ to P+680. On the basis of these results and similar effects in Mn-(plus Ca2+-)depleted PS II (M. Haumann et al., Biochemistry, 38 (1999) 1258-1267) we conclude that the presence of Ca2+ in the catalytic center is required to tune the apparent pK of a base cluster, B, to which YZ is linked by hydrogen bonds. The deposition of a proton on B within close proximity of YZ (not its release into the bulk!) is a necessary condition for the reduction in nanoseconds of P+680 and for the functioning of water oxidation. The removal of Ca2+ rises the pK of B, thereby disturbing the hydrogen bonded structure of YZB.
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Semin BK, Ivanov LI, Rubin AB, Carpentier R. pH-Dependent Extraction of Ca 2+ from Photosystem II Membranes and Thylakoid Membranes: Indication of a Ca 2+-Sensitive Site on the Acceptor Side of Photosystem II. Photochem Photobiol 1998. [DOI: 10.1111/j.1751-1097.1998.tb02511.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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43
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Tommos C, Hoganson CW, Valentin MD, Lydakis-Simantiris N, Dorlet P, Westphal K, Chu HA, McCracken J, Babcock GT. Manganese and tyrosyl radical function in photosynthetic oxygen evolution. Curr Opin Chem Biol 1998; 2:244-52. [PMID: 9667938 DOI: 10.1016/s1367-5931(98)80066-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Photosystem II catalyzes the photosynthetic oxidation of water to O2. The structural and functional basis for this remarkable process is emerging. The catalytic site contains a tetramanganese cluster, calcium, chloride and a redox-active tyrosine organized so as to promote electroneutral hydrogen atom abstraction from manganese-bound substrate water by the tyrosyl radical. Recent work is assessed within the framework of this model for the water oxidizing process.
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Affiliation(s)
- C Tommos
- Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
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44
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Hoganson CW, Babcock GT. A metalloradical mechanism for the generation of oxygen from water in photosynthesis. Science 1997; 277:1953-6. [PMID: 9302282 DOI: 10.1126/science.277.5334.1953] [Citation(s) in RCA: 467] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In plants and algae, photosystem II uses light energy to oxidize water to oxygen at a metalloradical site that comprises a tetranuclear manganese cluster and a tyrosyl radical. A model is proposed whereby the tyrosyl radical functions by abstracting hydrogen atoms from substrate water bound as terminal ligands to two of the four manganese ions. Molecular oxygen is produced in the final step in which hydrogen atom transfer and oxygen-oxygen bond formation occur together in a concerted reaction. This mechanism establishes clear analogies between photosynthetic water oxidation and amino acid radical function in other enzymatic reactions.
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Affiliation(s)
- C W Hoganson
- Department of Chemistry, Michigan State University, East Lansing, MI 48824-1322, USA
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Krieger A, Rutherford A. Comparison of chloride-depleted and calcium-depleted PSII: the midpoint potential of QA and susceptibility to photodamage. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(96)00117-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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46
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Boussac A. Quantification of the number of spins in the S2- and S3-states of Ca2+-depleted photosystem II by pulsed-EPR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1996. [DOI: 10.1016/s0005-2728(96)00107-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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47
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Booth P, Rutherford A, Boussac A. Location of the calcium binding site in Photosystem II: A Mn2+ substitution study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1996. [DOI: 10.1016/s0005-2728(96)00094-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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48
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Haumann M, Drevenstedt W, Hundelt M, Junge W. Photosystem II of green plants. Oxidation and deprotonation of the same component (histidine?) on S1∗ ⇒ S2∗ in chloride-depleted centers as on S2 ⇒ S3 in controls. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1996. [DOI: 10.1016/0005-2728(95)00152-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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49
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Bumann D, Oesterhelt D. Destruction of a single chlorophyll is correlated with the photoinhibition of photosystem II with a transiently inactive donor side. Proc Natl Acad Sci U S A 1995; 92:12195-9. [PMID: 11607621 PMCID: PMC40323 DOI: 10.1073/pnas.92.26.12195] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pigments destroyed during photoinhibition of water-splitting photosystem II core complexes from the green alga Chlamydomonas reinhardtii were studied. Under conditions of a transiently inactivated donor side, illumination leads to an irreversible inhibition of the electron transfer at the donor side that is paralleled by the destruction of chlorophylls a absorbing maximally around 674 and 682 nm. The observed stochiometry of 1 +/- 0.1 destroyed chlorophyll per inhibited photosystem II suggests that chlorophyll destruction could be the primary photodamage causing the inhibition of photosystem II under these conditions.
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Affiliation(s)
- D Bumann
- Department of Membrane Biochemistry, Max Planck Institute for Biochemistry, Martinsried, Germany
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50
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Gilchrist ML, Ball JA, Randall DW, Britt RD. Proximity of the manganese cluster of photosystem II to the redox-active tyrosine YZ. Proc Natl Acad Sci U S A 1995; 92:9545-9. [PMID: 7568170 PMCID: PMC40838 DOI: 10.1073/pnas.92.21.9545] [Citation(s) in RCA: 180] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Electron spin echo electron-nuclear double resonance (ESE-ENDOR) experiments performed on a broad radical electron paramagnetic resonance (EPR) signal observed in photosystem II particles depleted of Ca2+ indicate that this signal arises from the redox-active tyrosine YZ. The tyrosine EPR signal width is increased relative to that observed in a manganese-depleted preparation due to a magnetic interaction between the photosystem II manganese cluster and the tyrosine radical. The manganese cluster is located asymmetrically with respect to the symmetry-related tyrosines YZ and YD. The distance between the YZ tyrosine and the manganese cluster is estimated to be approximately 4.5 A. Due to this close proximity of the Mn cluster and the redox-active tyrosine YZ, we propose that this tyrosine abstracts protons from substrate water bound to the Mn cluster.
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Affiliation(s)
- M L Gilchrist
- Department of Chemistry, University of California, Davis 95616, USA
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