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Light-driven CO2 assimilation by photosystem II and its relation to photosynthesis. CHINESE JOURNAL OF CATALYSIS 2023. [DOI: 10.1016/s1872-2067(22)64170-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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2
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Sample Preparation and Data Collection for Electron Crystallographic Studies on Membrane Protein Structures and Lipid-Protein Interaction. Methods Mol Biol 2020. [PMID: 33368007 DOI: 10.1007/978-1-0716-0966-8_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Electron crystallography is a unique tool to study membrane protein structures and lipid-protein interactions in their native-like environments. Two-dimensional (2D) protein crystallization enables the lipids immobilized by the proteins, and the generated high-resolution density map allows us to model the atomic coordinates of the surrounding lipids to study lipid-protein interaction. This protocol describes the sample preparation for electron crystallographic studies, including back-injection method and carbon sandwich method. The protocols of data collection for electron crystallography, including electron imaging and diffraction, of the 2D membrane crystal will be followed.
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Mackness BC, Jaworski JA, Boudanova E, Park A, Valente D, Mauriac C, Pasquier O, Schmidt T, Kabiri M, Kandira A, Radošević K, Qiu H. Antibody Fc engineering for enhanced neonatal Fc receptor binding and prolonged circulation half-life. MAbs 2019; 11:1276-1288. [PMID: 31216930 PMCID: PMC6748615 DOI: 10.1080/19420862.2019.1633883] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The neonatal Fc receptor (FcRn) promotes antibody recycling through rescue from normal lysosomal degradation. The binding interaction is pH-dependent with high affinity at low pH, but not under physiological pH conditions. Here, we combined rational design and saturation mutagenesis to generate novel antibody variants with prolonged half-life and acceptable development profiles. First, a panel of saturation point mutations was created at 11 key FcRn-interacting sites on the Fc region of an antibody. Multiple variants with slower FcRn dissociation kinetics than the wildtype (WT) antibody at pH 6.0 were successfully identified. The mutations were further combined and characterized for pH-dependent FcRn binding properties, thermal stability and the FcγRIIIa and rheumatoid factor binding. The most promising variants, YD (M252Y/T256D), DQ (T256D/T307Q) and DW (T256D/T307W), exhibited significantly improved binding to FcRn at pH 6.0 and retained similar binding properties as WT at pH 7.4. The pharmacokinetics in human FcRn transgenic mice and cynomolgus monkeys demonstrated that these properties translated to significantly prolonged plasma elimination half-life compared to the WT control. The novel variants exhibited thermal stability and binding to FcγRIIIa in the range comparable to clinically validated YTE and LS variants, and showed no enhanced binding to rheumatoid factor compared to the WT control. These engineered Fc mutants are promising new variants that are widely applicable to therapeutic antibodies, to extend their circulation half-life with obvious benefits of increased efficacy, and reduced dose and administration frequency.
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Affiliation(s)
| | | | | | - Anna Park
- Biologics Research, Sanofi , Framingham , MA , USA
| | | | | | | | | | | | | | | | - Huawei Qiu
- Biologics Research, Sanofi , Framingham , MA , USA
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Zhou Y, Wu Y, Yao M, Liu Z, Chen J, Chen J, Tian L, Han G, Shen JR, Wang F. Probing the Lysine Proximal Microenvironments within Membrane Protein Complexes by Active Dimethyl Labeling and Mass Spectrometry. Anal Chem 2016; 88:12060-12065. [DOI: 10.1021/acs.analchem.6b02502] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ye Zhou
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Wu
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Mingdong Yao
- State
Key Laboratory of Catalysis, Dalian National Laboratory for Clean
Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Zheyi Liu
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jin Chen
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Chen
- State
Key Laboratory of Catalysis, Dalian National Laboratory for Clean
Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Lirong Tian
- Key
Laboratory of Photobiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangye Han
- Key
Laboratory of Photobiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
| | - Jian-Ren Shen
- Key
Laboratory of Photobiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
- Photosynthesis
Research Center, Graduate School of Natural Science and Technology, Okayama University, 1-1, Naka 3-chome, Tsushima, Okayama 700-8530, Japan
| | - Fangjun Wang
- Key Laboratory of Separation Sciences for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
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Kern J, Renger G. Photosystem II: structure and mechanism of the water:plastoquinone oxidoreductase. PHOTOSYNTHESIS RESEARCH 2007; 94:183-202. [PMID: 17634752 DOI: 10.1007/s11120-007-9201-1] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 05/16/2007] [Indexed: 05/07/2023]
Abstract
This mini-review briefly summarizes our current knowledge on the reaction pattern of light-driven water splitting and the structure of Photosystem II that acts as a water:plastoquinone oxidoreductase. The overall process comprises three types of reaction sequences: (a) light-induced charge separation leading to formation of the radical ion pair P680+*QA(-*) ; (b) reduction of plastoquinone to plastoquinol at the QB site via a two-step reaction sequence with QA(-*) as reductant and (c) oxidative water splitting into O2 and four protons at a manganese-containing catalytic site via a four-step sequence driven by P680+* as oxidant and a redox active tyrosine YZ acting as mediator. Based on recent progress in X-ray diffraction crystallographic structure analysis the array of the cofactors within the protein matrix is discussed in relation to the functional pattern. Special emphasis is paid on the structure of the catalytic sites of PQH2 formation (QB-site) and oxidative water splitting (Mn4OxCa cluster). The energetics and kinetics of the reactions taking place at these sites are presented only in a very concise manner with reference to recent up-to-date reviews. It is illustrated that several questions on the mechanism of oxidative water splitting and the structure of the catalytic sites are far from being satisfactorily answered.
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Affiliation(s)
- Jan Kern
- Institut für Chemie, Max-Volmer-Laboratorium für Biophysikalische Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany.
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Kern J, Biesiadka J, Loll B, Saenger W, Zouni A. Structure of the Mn4-Ca cluster as derived from X-ray diffraction. PHOTOSYNTHESIS RESEARCH 2007; 92:389-405. [PMID: 17492491 DOI: 10.1007/s11120-007-9173-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 04/10/2007] [Indexed: 05/15/2023]
Abstract
The catalytic centre for light-induced water oxidation in photosystem II (PSII) is a multinuclear metal cluster containing four manganese and one calcium cations. Knowing the structure of this biological catalyst is of utmost importance for unravelling the mechanism of water oxidation in photosynthesis. In this review we describe the current state of the X-ray structure determination at 3.0 A resolution of the water oxidation complex (WOC) of PSII. The arrangement of metal cations in the cluster, their coordination and protein surroundings are discussed with regard to spectroscopic and mutagenesis studies. Limitations of the presently available structural data are pointed out and possible perspectives for the future are outlined, including the combination of X-ray diffraction and X-ray spectroscopy on single crystals.
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Affiliation(s)
- Jan Kern
- Institut für Chemie, Max Volmer Laboratorium für Biophysikalische Chemie, Sekr. PC 14, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
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Tohri A, Dohmae N, Suzuki T, Ohta H, Inoue Y, Enami I. Identification of domains on the extrinsic 23 kDa protein possibly involved in electrostatic interaction with the extrinsic 33 kDa protein in spinach photosystem II. ACTA ACUST UNITED AC 2004; 271:962-71. [PMID: 15009208 DOI: 10.1111/j.1432-1033.2004.03998.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To elucidate the domains on the extrinsic 23 kDa protein involved in electrostatic interaction with the extrinsic 33 kDa protein in spinach photosystem II, we modified amino or carboxyl groups of the 23 kDa protein to uncharged methyl ester groups with N-succinimidyl propionate or glycine methyl ester in the presence of a water-soluble carbodiimide, respectively. The N-succinimidyl propionate-modified 23 kDa protein did not bind to the 33 kDa protein associated with PSII membranes, whereas the glycine methyl ester-modified 23 kDa protein completely bound. This indicates that positive charges on the 23 kDa protein are important for electrostatic interaction with the 33 kDa protein associated with the PSII membranes. Mapping of the N-succinimidyl propionate-modified sites of the 23 kDa protein was performed using Staphylococcus V8 protease digestion of the modified protein followed by determination of the mass of the resultant peptide fragments with MALDI-TOF MS. The results showed that six domains (Lys11-Lys14, Lys27-Lys38, Lys40, Lys90-Lys96, Lys143-Lys152, Lys166-Lys174) were modified with N-succinimidyl propionate. In these domains, Lys11, Lys13, Lys33, Lys38, Lys143, Lys166, Lys170 and Lys174 were wholly conserved in the 23 kDa protein from 12 species of higher plants. These positively charged lysyl residues on the 23 kDa protein may be involved in electrostatic interactions with the negatively charged carboxyl groups on the 33 kDa protein, the latter has been suggested to be important for the 23 kDa binding [Bricker, T.M. & Frankel, L.K. (2003) Biochemistry42, 2056-2061].
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Affiliation(s)
- Akihiko Tohri
- Department of Biology, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo, Japan
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Rhee KH. Photosystem II: the solid structural era. ANNUAL REVIEW OF BIOPHYSICS AND BIOMOLECULAR STRUCTURE 2001; 30:307-28. [PMID: 11340062 DOI: 10.1146/annurev.biophys.30.1.307] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Understanding the precise role of photosystem II as an element of oxygenic photosynthesis requires knowledge of the molecular structure of this membrane protein complex. The past few years have been particularly exciting because the structural era of the plant photosystem II has begun. Although the atomic structure has yet to be determined, the map obtained at 6 A resolution by electron crystallography allows assignment of the key reaction center subunits with their associated pigment molecules. In the following, we first review the structural details that have recently emerged and then discuss the primary and secondary photochemical reaction pathways. Finally, in an attempt to establish the evolutionary link between the oxygenic and the anoxygenic photosynthesis, a framework structure common to all photosynthetic reaction centers has been defined, and the implications have been described.
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Affiliation(s)
- K H Rhee
- Laboratory of Molecular Biology, Medical Research Council, Hills Road, Cambridge, CB2 2QH, United Kingdom.
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Abstract
Two-dimensional crystallogenesis is a crucial step in the long road that leads to the determination of macromolecules structure via electron crystallography. The necessity of having large and highly ordered samples can hold back the resolution of structural works for a long time, and this, despite improvements made in electron microscopes or image processing. Today, finding good conditions for growing two-dimensional crystals still rely on either "biocrystallo-cooks" or on lucky ones. The present review presents the field by first describing the different crystals that one can encounter and the different crystallisation methods used. Then, the effects of different components (such as protein, lipids, detergent, buffer, and temperature) and the different methods (dialysis, hydrophobic adsorption) are discussed. This discussion is punctuated by correspondences made to the world of three-dimensional crystallogenesis. Finally, a guide for setting up 2D crystallogenesis experiments, built on the discussion mentioned before, is proposed to the reader. More than giving recipes, this review is meant to open up the discussions in this field.
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Affiliation(s)
- G Mosser
- LPCC, UMR168-CNRS, Institut Curie-Section de Recherche, 11 rue Pierre et Marie Curie, 75005 Paris, France.
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Shen JR, Kamiya N. Crystallization and the crystal properties of the oxygen-evolving photosystem II from Synechococcus vulcanus. Biochemistry 2000; 39:14739-44. [PMID: 11101288 DOI: 10.1021/bi001402m] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A photosystem II (PSII) complex highly active in oxygen evolution was purified and crystallized from a thermophilic cyanobacterium, Synechococcus vulcanus. The PSII complex in the crystals contained the D1/D2 reaction center subunits, CP47 and CP43 (two chlorophyll-binding core antenna proteins of photosystem II), cytochrome b-559 alpha- and beta-subunits, several low molecular weight subunits, and three extrinsic proteins, that is, 33 and 12 kDa proteins and cytochrome c-550. The PSII complex also retained a high rate of oxygen evolution. The apparent molecular mass of the PSII in the crystals was determined to be 580 kDa by gel filtration chromatography, indicating that the PSII crystallized is a dimer. The crystals diffracted to a maximum resolution of 3.5 A at a cryogenic temperature using X-rays from a synchrotron radiation source, SPring-8. The crystals belonged to an orthorhombic system, and the space group was P2(1)2(1)2(1) with unit cell dimensions of a = 129.7 A, b = 226.5 A, and c = 307.8 A. Each asymmetric unit contained one PSII dimer, which gave rise to a specific volume (V(M)) of 3.6 A(3)/Da based on the calculated molecular mass of 310 kDa for a PSII monomer and an estimated solvent content of 66%. Multiple data sets of native crystals have been collected and processed to 4.0 A, indicating that our crystals are suitable for structure analysis at this resolution.
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Affiliation(s)
- J R Shen
- Photosynthesis Research Laboratory and Division of Bio-Crystallography Technology, RIKEN Harima Institute, Koto 1-1-1, Mikazuki-cho, Sayo, Hyogo 679-5148, Japan.
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Rigaud J, Chami M, Lambert O, Levy D, Ranck J. Use of detergents in two-dimensional crystallization of membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1508:112-28. [PMID: 11090821 DOI: 10.1016/s0005-2736(00)00307-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Structure determination at high resolution is actually a difficult challenge for membrane proteins and the number of membrane proteins that have been crystallized is still small and far behind that of soluble proteins. Because of their amphiphilic character, membrane proteins need to be isolated, purified and crystallized in detergent solutions. This makes it difficult to grow the well-ordered three-dimensional crystals that are required for high resolution structure analysis by X-ray crystallography. In this difficult context, growing crystals confined to two dimensions (2D crystals) and their structural analysis by electron crystallography has opened a new way to solve the structure of membrane proteins. However, 2D crystallization is one of the major bottlenecks in the structural studies of membrane proteins. Advances in our understanding of the interaction between proteins, lipids and detergents as well as development and improvement of new strategies will facilitate the success rate of 2D crystallization. This review deals with the various available strategies for obtaining 2D crystals from detergent-solubilized intrinsic membrane proteins. It gives an overview of the methods that have been applied and gives details and suggestions of the physical processes leading to the formation of the ordered arrays which may be of help for getting more proteins crystallized in a form suitable for high resolution structural analysis by electron crystallography.
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Affiliation(s)
- J Rigaud
- Institut Curie, Section de Recherche, UMR-CNRS 168 and LRC-CEA 8, 11 rue Pierre et Marie Curie, 75231, Paris, France.
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Kuhl H, Kruip J, Seidler A, Krieger-Liszkay A, Bunker M, Bald D, Scheidig AJ, Rögner M. Towards structural determination of the water-splitting enzyme. Purification, crystallization, and preliminary crystallographic studies of photosystem II from a thermophilic cyanobacterium. J Biol Chem 2000; 275:20652-9. [PMID: 10748017 DOI: 10.1074/jbc.m001321200] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A photosystem II preparation from the thermophilic cyanobacterium Synechococcus elongatus, which is especially suitable for three-dimensional crystallization in a fully active form was developed. The efficient purification method applied here yielded 10 mg of protein of a homogenous dimeric complex of about 500 kDa within 2 days. Detailed characterization of the preparation demonstrated a fully active electron transport chain from the manganese cluster to plastoquinone in the Q(B) binding site. The oxygen-evolving activity, 5000-6000 micromol of O(2)/(h.mg of chlorophyll), was the highest so far reported and is maintained even at temperatures as high as 50 degrees C. The crystals obtained by the vapor diffusion method diffracted to a resolution of 4.3 A. The space group was determined to be P2(1)2(1)2(1) with four photosystem II dimers per unit cell. Analysis of the redissolved crystals revealed that activity, supramolecular organization, and subunit composition were maintained during crystallization.
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Affiliation(s)
- H Kuhl
- Department of Plant Biochemistry, Faculty of Biology, Ruhr-University Bochum, D-44780 Bochum, Germany
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Does photoinhibition and/or phosphorylation of photosystem II influence its in vivo oligomeric state? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1999. [DOI: 10.1016/s0005-2728(99)00075-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Gallant J, Desbat B, Vaknin D, Salesse C. Polarization-modulated infrared spectroscopy and x-ray reflectivity of photosystem II core complex at the gas-water interface. Biophys J 1998; 75:2888-99. [PMID: 9826610 PMCID: PMC1299961 DOI: 10.1016/s0006-3495(98)77731-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The state of photosystem II core complex (PS II CC) in monolayer at the gas-water interface was investigated using in situ polarization-modulated infrared reflection absorption spectroscopy and x-ray reflectivity techniques. Two approaches for preparing and manipulating the monolayers were examined and compared. In the first, PS II CC was compressed immediately after spreading at an initial surface pressure of 5.7 mN/m, whereas in the second, the monolayer was incubated for 30 min at an initial surface pressure of 0.6 mN/m before compression. In the first approach, the protein complex maintained its native alpha-helical conformation upon compression, and the secondary structure of PS II CC was found to be stable for 2 h. The second approach resulted in films showing stable surface pressure below 30 mN/m and the presence of large amounts of beta-sheets, which indicated denaturation of PS II CC. Above 30 mN/m, those films suffered surface pressure instability, which had to be compensated by continuous compression. This instability was correlated with the formation of new alpha-helices in the film. Measurements at 4 degreesC strongly reduced denaturation of PS II CC. The x-ray reflectivity studies indicated that the spread film consists of a single protein layer at the gas-water interface. Altogether, this study provides direct structural and molecular information on membrane proteins when spread in monolayers at the gas-water interface.
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Affiliation(s)
- J Gallant
- GREIB, Département de Chimie-Biologie, Université du Québec à Trois-Rivières, Trois-Rivières, Québec, Canada
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Lukins PB, Oates T. Single-molecule high-resolution structure and electron conduction of photosystem II from scanning tunneling microscopy and spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1409:1-11. [PMID: 9804863 DOI: 10.1016/s0005-2728(98)00137-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Scanning tunneling microscopy (STM) and spectroscopy (STS) were used to obtain the first direct high resolution ( approximately 0.3 nm) images of single isolated Photosystem II (PS II) molecules, and to determine the supramolecular organization of oxygen-evolving PS II core complexes and PS II membrane fragments including the identification, assignment, location and dimensions of the polypeptide units. Our results predict a unique structural model which we then compare with alternative models. We show that the combination of quasi-constant-height mode STM operation, STS and suitable choice of sample-substrate preparations can be used to enable investigation of the structure and function of single PS II particles under normal thermodynamic and hydration conditions without the requirement and complications of ordered PS II arrays or crystals. STS was also used to characterize single-molecule electron conduction and tunneling mechanisms in PS II including the semiconduction and photoconduction behavior of the reaction center and photoexcitation effects in the light-harvesting complex LHC II.
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Affiliation(s)
- P B Lukins
- School of Physics, A28, University of Sydney, Sydney, NSW 2006, Australia.
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Mayanagi K, Ishikawa T, Toyoshima C, Inoue Y, Nakazato K. Three-dimensional electron microscopy of the photosystem II core complex. J Struct Biol 1998; 123:211-24. [PMID: 9878576 DOI: 10.1006/jsbi.1998.4033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A three-dimensional image of the spinach photosystem II core complex composed of CP47, D1, D2, cytochrome b-559, and psbI gene product was reconstructed at 20-A resolution from the two-dimensional crystals negatively stained with phosphotungstate. Confirming the previous proposal, the crystal had a p22121 symmetry. One PSII core complex was measured to be 80 x 80 A in the membrane plane and 88 A normal to it. The mass distribution was asymmetric about the lipid bilayer, consistent with predictions from the amino acid sequences. The lumenal mass consisted of three domains forming a characteristic triangular platform with another domain on top of it. Three stromal domains were smaller and linearly arranged. Due to strong stain exclusion in the hydrophobic core part of the lipid bilayer, the transmembrane region appeared to be imaged with a reversed contrast. Inverting the contrast resulted in a reasonable density distribution for that part. Thus, though the information on the transmembrane region is limited, the domain structure of the PSII core complex was revealed and allowed us to propose a model for the arrangement of subunits in the PSII core complex.
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Affiliation(s)
- K Mayanagi
- Photosynthesis Research Laboratory, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama, 351-01, Japan
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Walz T, Grigorieff N. Electron Crystallography of Two-Dimensional Crystals of Membrane Proteins. J Struct Biol 1998; 121:142-61. [PMID: 9618341 DOI: 10.1006/jsbi.1998.3945] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Electron microscopy has become a powerful technique, along with X-ray crystallography and nuclear magnetic resonance spectroscopy, to study the three-dimensional structure of biological molecules. It has evolved into a number of methods dealing with a wide range of biological samples, with electron crystallography of two-dimensional crystals being so far the only method allowing data collection at near-atomic resolution. In this paper, we review the methodology of electron crystallography and its application to membrane proteins, starting with the pioneering work on bacteriorhodopsin, which led to the first visualization of the secondary structure of a membrane protein in 1975. Since then, improvements in instrumentation, sample preparation, and data analysis have led to atomic models for bacteriorhodopsin and light-harvesting complex II from higher plants. The structures of many more membrane proteins have been studied by electron crystallography and in this review examples are included where a resolution of better than 10 Å has been achieved. Indeed, in some of the given examples an atomic model can be expected in the near future. Finally, a brief outlook is given on current and future developments of electron crystallographic methods. Copyright 1998 Academic Press.
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Affiliation(s)
- T Walz
- Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, United Kingdom
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Lyon MK. Multiple crystal types reveal photosystem II to be a dimer. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1364:403-19. [PMID: 9630730 DOI: 10.1016/s0005-2728(98)00064-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three types of photosystem II (PS II) crystals have been produced using a variety of detergents. Intermediate stages of crystal formation were examined and it was determined that each crystal probably originates from a single grana membrane. Each crystal type was examined by electron microscopy and image processing, providing three different projection maps. The highest resolution results came from type 1 and type 2 crystals. Projection maps from these crystals were examined for two-fold symmetry via difference maps between the unsymmetrized averages and their 180 degrees rotation. A comparison of the final maps shows a high degree of two-fold symmetry, with only slight differences noted in the low density regions of the two halves of the structure. The interpretation is that PS II is a dimer, with the further suggestion that the two reaction center cores may have slightly different complements of antennae polypeptides.
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Affiliation(s)
- M K Lyon
- Department of Molecular, Cellular and Developmental Biology, Campus Box 347, University of Colorado, Boulder, CO 80307, USA.
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Okada T, Takeda K, Kouyama T. Highly Selective Separation of Rhodopsin from Bovine Rod Outer Segment Membranes Using Combination of Divalent Cation and Alkyl(thio)glucoside. Photochem Photobiol 1998. [DOI: 10.1111/j.1751-1097.1998.tb09084.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Okada T, Takeda K, Kouyama T. Highly Selective Separation of Rhodopsin from Bovine Rod Outer Segment Membranes Using Combination of Divalent Cation and Alkyl(thio)glucoside. Photochem Photobiol 1998. [DOI: 10.1111/j.1751-1097.1998.tb09445.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Stoylova SS, Flint TD, Ford RC, Holzenburg A. Projection structure of photosystem II In vivo determined by cryo-electron crystallography. Micron 1997. [DOI: 10.1016/s0968-4328(97)00045-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Hasler L, Ghanotakis D, Fedtke B, Spyridaki A, Miller M, Müller SA, Engel A, Tsiotis G. Structural Analysis of Photosystem II: Comparative Study of Cyanobacterial and Higher Plant Photosystem II Complexes. J Struct Biol 1997; 119:273-83. [PMID: 9245767 DOI: 10.1006/jsbi.1997.3889] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Oxygen evolving photosystem II (PSII-OEC) complexes and PSII core complexes were isolated from spinach and the thermophilic cyanobacterium Synechococcus sp. OD24 and characterized by gel electrophoresis, immunoblotting, and absorbance spectroscopy. The mass of the core complexes was determined by scanning transmission electron microscopy (STEM) and found to be 281 ± 65 kDa for spinach and 313 ± 52 kDa for Synechococcus sp. OD24. The mass of the spinach PSII-OEC complex was 327 ± 64 kDa. Digital images of negatively stained PSII-OEC and PSII core complexes were recorded by STEM and analyzed by single particle averaging. All monomeric complexes showed similar morphologies and were of comparable length (14 nm) and width (10 nm). The averages revealed a pseudo-twofold symmetry axis, which is a prominent structural element of the monomeric form. Difference maps between the averaged projections of the oxygen evolving complexes and the core complexes from both species indicated where the 33-kDa extrinsic manganese stabilizing protein is bound. A symmetric organization of the PSII complex, with the PsbA and the PsbD proteins in the center and symmetrically arranged PsbB and PsbC proteins at the periphery of the monomeric complex, is proposed.
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Affiliation(s)
- L Hasler
- Biozentrum, University of Basel, Klingelbergstrasse 70, Basel, CH-4056, Switzerland
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24
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Heymann JB, Müller DJ, Mitsuoka K, Engel A. Electron and atomic force microscopy of membrane proteins. Curr Opin Struct Biol 1997; 7:543-9. [PMID: 9266177 DOI: 10.1016/s0959-440x(97)80120-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Electron crystallography is becoming a powerful tool for the resolution of membrane protein structures. The past year has seen the production of a bacteriorhodopsin model at 3.5 A and the structure of aquaporin 1 approaching atomic resolution. Determination of surface topographies of 2D crystals using the atomic force microscope is similarly advancing to a level that reveals submolecular details. As the latter is operated in solution, membrane proteins can be observed at work.
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Affiliation(s)
- J B Heymann
- ME Müller-Institute for Microscopic Structural Biology at the Biozentrum, University of Basel, Switzerland
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25
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De Las Rivas J, Barber J. Structure and thermal stability of photosystem II reaction centers studied by infrared spectroscopy. Biochemistry 1997; 36:8897-903. [PMID: 9220977 DOI: 10.1021/bi970684w] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The secondary structure of photosystem II reaction centers isolated from pea has been deduced from quantitative analysis of the component bands of the infrared amide I spectral region, determined by FTIR spectroscopy. The analysis shows the isolated complex to consist of 40% alpha-helix, 10% beta-sheet, 14% beta-strands (or extended chains), 17% turns, 15% loops, and 3% nonordered segments. These structural protein elements were determined for samples in H2O, in D2O, and in dried films. The isolated reaction center, composed of proteins D1,D2,cytochrome b559, and PsbI, has been predicted to contain a total of 13 transmembrane alpha-helices, which conveys a percentage of this type of structure congruent with the structural determination deduced from FTIR spectra. The process of thermal destabilization of the reaction centers has also been studied by FTIR spectroscopy, showing a clear main conformational transition at 42 degrees C, which indicates a high thermal sensitivity of the secondary structure of this protein complex. Such thermal instability may correlate with the well-described high sensitivity of photosystem II to damage and may relate to the process of rapid protein degradation that photosystem II suffers during photoinhibition of plants.
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Affiliation(s)
- J De Las Rivas
- Department of Biochemistry and Molecular Biology, Faculty of Science, University of the Basque Country, P.O. Box 644, E48080 Bilbao, Spain.
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26
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Shao L, Tao N, Leblanc R. Probing the microelastic properties of nanobiological particles with tapping mode atomic force microscopy. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00585-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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27
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Characterization by electron microscopy of dimeric Photosystem II core complexes from spinach with and without CP43. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(97)00040-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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28
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Morris EP, Hankamer B, Zheleva D, Friso G, Barber J. The three-dimensional structure of a photosystem II core complex determined by electron crystallography. Structure 1997; 5:837-49. [PMID: 9261075 DOI: 10.1016/s0969-2126(97)00237-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Photosystem II (PSII) is a multisubunit protein complex which is embedded in the photosynthetic membranes of plants. It uses light energy to split water into molecular oxygen and reducing equivalents. PSII can be isolated with varying degrees of complexity in terms of its subunit composition and activity. To date, no three-dimensional (3-D) structure of the PSII complex has been determined which allows location of the proteins within the PSII complex and their orientation in relation to the thylakoid membrane. RESULTS Two-dimensional (2-D) PSII core complex crystals composed of the two reaction centre proteins, D1 and D2, two chlorophyll-binding proteins, CP47 and CP43, cytb559 and associated low molecular weight proteins were formed after reconstituting the isolated complex into purified thylakoid lipids. Electron micrographs of negatively stained crystals were used for 2-D and 3-D image analyses. In the resulting maps, the PSII complex is composed of two halves related by twofold rotational symmetry, thus, confirming the dimeric nature of the complex; each monomer appears to contain five domains. Comparison of the 3-D images with platinum shadowed images of the crystals allowed the likely lumenal and stromal surfaces of the complex to be identified and regions contained within the membrane to be inferred. The projection structure of 2-D crystals of a smaller CP47-D1-D2-cytb559 complex was used to identify the domains apparently associated with CP43. CONCLUSION The results indicate that PSII probably exists as a dimer in vivo. The extensive proteinaceous protrusions from the lumenal surface have been tentatively assigned to hydrophilic loops of CP47 and CP43; the positioning of these loops possibly implies their involvement in the water-splitting process.
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Affiliation(s)
- E P Morris
- Wolfson Laboratories, Department of Biochemistry, Imperial College of Science, Technology & Medicine, London, UK
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29
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Hankamer B, Barber J, Boekema EJ. STRUCTURE AND MEMBRANE ORGANIZATION OF PHOTOSYSTEM II IN GREEN PLANTS. ACTA ACUST UNITED AC 1997; 48:641-671. [PMID: 15012277 DOI: 10.1146/annurev.arplant.48.1.641] [Citation(s) in RCA: 276] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Photosystem II (PSII) is the pigment protein complex embedded in the thylakoid membrane of higher plants, algae, and cyanobacteria that uses solar energy to drive the photosynthetic water-splitting reaction. This chapter reviews the primary, secondary, tertiary, and quaternary structures of PSII as well as the function of its constituent subunits. The understanding of in vivo organization of PSII is based in part on freeze-etched and freeze-fracture images of thylakoid membranes. These images show a resolution of about 40-50 A and so provide information mainly on the localization, heterogeneity, dimensions, and shapes of membrane-embedded PSII complexes. Higher resolution of about 15-40 A has been obtained from single particle images of isolated PSII complexes of defined and differing subunit composition and from electron crystallography of 2-D crystals. Observations are discussed in terms of the oligomeric state and subunit organization of PSII and its antenna components.
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Affiliation(s)
- Ben Hankamer
- Wolfson Laboratories, Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AY, United Kingdom, Biophysical Chemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, Groningen, NL-9747 AG The Netherlands
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30
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Uphaus RA, Fang JY, Picorel R, Chumanov G, Wang JY, Cotton TM, Seibert M. Langmuir-Blodgett and X-ray diffraction studies of isolated photosystem II reaction centers in monolayers and multilayers: physical dimensions of the complex. Photochem Photobiol 1997; 65:673-9. [PMID: 9114743 DOI: 10.1111/j.1751-1097.1997.tb01910.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The photosystem II (PSII) reaction center (RC) is a hydrophobic intrinsic protein complex that drives the water-oxidation process of photosynthesis. Unlike the bacterial RC complex, an X-ray crystal structure of the PSII RC is not available. In order to determine the physical dimensions of the isolated PSII RC complex, we applied Langmuir techniques to determine the cross-sectional area of an isolated RC in a condensed monolayer film. Low-angle X-ray diffraction results obtained by examining Langmuir-Blodgett multilayer films of alternating PSII RC/Cd stearate monolayers were used to determine the length (or height; z-direction, perpendicular to the plane of the original membrane) of the complex. The values obtained for a PSII RC monomer were 26 nm2 and 4.8 nm, respectively, and the structural integrity of the RC in the multilayer film was confirmed by several approaches. Assuming a cylindrical-type RC structure, the above dimensions lead to a predicted volume of about 125 nm3. This value is very close to the expected volume of 118 nm3, calculated from the known molecular weight and partial specific volume of the PSII RC proteins. This same type of comparison was also made with the Rhodobacter sphaeroides RC based on published data, and we conclude that the PSII RC is much shorter in length and has a more regular solid geometric structure than the bacterial RC. Furthermore, the above dimensions of the PSII RC and those of PSII core (RC plus proximal antenna) proteins protruding outside the plane of the PSII membrane into the lumenal space as imaged by scanning tunneling microscopy (Seibert, Aust. J. Pl. Physiol. 22, 161-166, 1995) fit easily into the known dimensions of the PSII core complex visualized by others as electron-density projection maps. From this we conclude that the in situ PSII core complex is a dimeric structure containing two copies of the PSII RC.
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Affiliation(s)
- R A Uphaus
- Ames Laboratory, Iowa State University, USA
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31
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Rosenberg MF, Holzenburg A, Shepherd FH, Nicholson WV, Flint TD, Ford RC. Rebinding of the extrinsic proteins of Photosystem II studied by electron microscopy and single particle alignment: an assessment with small two-dimensional ordered arrays of Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1997. [DOI: 10.1016/s0005-2728(96)00124-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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32
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Tsiotis G, McDermott G, Ghanotakis D. Progress towards structural elucidation of Photosystem II. PHOTOSYNTHESIS RESEARCH 1996; 50:93-101. [PMID: 24271928 DOI: 10.1007/bf00014881] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/1996] [Accepted: 10/09/1996] [Indexed: 06/02/2023]
Abstract
In recent years Photosystem II, and in particular the oxygen evolving component of the enzyme, have been the subject of intense biochemical and biophysical analysis. To date no high resolution structural model of the complex has been produced. As a consequence unambiguous interpretation of much experimental data has proven difficult, leading to a lack of consensus over many basic questions regarding the mechanisms involved, the oligomerization state of the enzyme in vivo and even the exact biochemical composition.This review is a summary of the progress towards the production of a structural model of PS II-derived from either X-ray crystallography or electron microscopy based techniques-and the current opinions, which have arisen from these structural analyses, on the structural topology and assemblage of the various subunits that constitute the complex.
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Affiliation(s)
- G Tsiotis
- M. Müller Institute for Microscopical Structure Biology, Biozentrum, University of Basel, Klingelbergstr. 70, CH-4056, Basel, Switzerland
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33
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Bald D, Kruip J, Rögner M. Supramolecular architecture of cyanobacterial thylakoid membranes: How is the phycobilisome connected with the photosystems? PHOTOSYNTHESIS RESEARCH 1996; 49:103-18. [PMID: 24271608 DOI: 10.1007/bf00117661] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/1996] [Accepted: 06/25/1996] [Indexed: 05/06/2023]
Abstract
Cyanobacteria, as the most simple organisms to perform oxygenic photosynthesis differ from higher plants especially with respect to the thylakoid membrane structure and the antenna system used to capture light energy. Cyanobacterial antenna systems, the phycobilisomes (PBS), have been shown to be associated with Photosystem 2 (PS 2) at the cytoplasmic side, forming a PS 2-PBS-supercomplex, the structure of which is not well understood. Based on structural data of PBS and PS 2, a model for such a supercomplex is presented. Its key features are the PS 2 dimer as prerequisite for formation of the supercomplex and the antiparallel orientation of PBS-cores and the two PS 2 monomers which form the 'contact area' within the supercomplex. Possible consequences for the formation of 'superstructures' (PS 2-PBS rows) within the thylakoid membrane under so-called 'state 1' conditions are discussed. As there are also indications for specific functional connections of PBS with Photosystem 1 (PS 1) under so-called 'state 2' conditions, we show a model which reconciles the need for a structural interaction between PBS and PS 1 with the difference in structural symmetry (2-fold rotational symmetry of PBS-cores, 3-fold rotational symmetry of trimeric PS 1). Finally, the process of dynamic coupling and uncoupling of PBS to PS 1 and PS 2, based on the presented models, shows analogies to mechanisms for the regulation of photosynthetic electron flow in higher plants-despite the very different organization of their thylakoid membranes in comparison to cyanobacteria.
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Affiliation(s)
- D Bald
- Institute of Botany, University of Münster, Schlossgarten 3, D-48149, Münster, Germany
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