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Abstract
From the earliest work on regular arrays in negative stain, electron crystallography has contributed greatly to our understanding of the structure and function of biological macromolecules. The development of electron cryo-microscopy (cryo-EM) then lead to the first groundbreaking atomic models of the membrane proteins bacteriorhodopsin and light harvesting complex II within lipid bilayers. Key contributions towards cryo-EM and electron crystallography methods included specimen preparation and vitrification, liquid-helium cooling, data collection, and image processing. These methods are now applied almost routinely to both membrane and soluble proteins. Here we outline the advances and the breakthroughs that paved the way towards high-resolution structures by electron crystallography, both in terms of methods development and biological milestones.
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Dockter C, Müller AH, Dietz C, Volkov A, Polyhach Y, Jeschke G, Paulsen H. Rigid core and flexible terminus: structure of solubilized light-harvesting chlorophyll a/b complex (LHCII) measured by EPR. J Biol Chem 2012; 287:2915-25. [PMID: 22147706 PMCID: PMC3268448 DOI: 10.1074/jbc.m111.307728] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 11/24/2011] [Indexed: 11/06/2022] Open
Abstract
The structure of the major light-harvesting chlorophyll a/b complex (LHCII) was analyzed by pulsed EPR measurements and compared with the crystal structure. Site-specific spin labeling of the recombinant protein allowed the measurement of distance distributions over several intra- and intermolecular distances in monomeric and trimeric LHCII, yielding information on the protein structure and its local flexibility. A spin label rotamer library based on a molecular dynamics simulation was used to take the local mobility of spin labels into account. The core of LHCII in solution adopts a structure very similar or identical to the one seen in crystallized LHCII trimers with little motional freedom as indicated by narrow distance distributions along and between α helices. However, distances comprising the lumenal loop domain show broader distance distributions, indicating some mobility of this loop structure. Positions in the hydrophilic N-terminal domain, upstream of the first trans-membrane α helix, exhibit more and more mobility the closer they are to the N terminus. The nine amino acids at the very N terminus that have not been resolved in any of the crystal structure analyses give rise to very broad and possibly bimodal distance distributions, which may represent two families of preferred conformations.
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Affiliation(s)
- Christoph Dockter
- From the Institut für Allgemeine Botanik der Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - André H. Müller
- From the Institut für Allgemeine Botanik der Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Carsten Dietz
- From the Institut für Allgemeine Botanik der Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Aleksei Volkov
- the Max-Planck-Institut für Polymerforschung, 55021 Mainz, Germany, and
| | - Yevhen Polyhach
- the Laboratorium für Physikalische Chemie, Eidgenössische Technische Hochschule, 8093 Zürich, Switzerland
| | - Gunnar Jeschke
- the Laboratorium für Physikalische Chemie, Eidgenössische Technische Hochschule, 8093 Zürich, Switzerland
| | - Harald Paulsen
- From the Institut für Allgemeine Botanik der Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
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3
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Butler PJ, Kühlbrandt W. Determination of the aggregate size in detergent solution of the light-harvesting chlorophyll a/b-protein complex from chloroplast membranes. Proc Natl Acad Sci U S A 2010; 85:3797-801. [PMID: 16593931 PMCID: PMC280306 DOI: 10.1073/pnas.85.11.3797] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The molecular mass of an oligomeric integral membrane protein, the light-harvesting chlorophyll a/b-protein complex from the photosynthetic membranes of chloroplasts, has been determined in detergent solution by analytical ultracentrifugation and measurement of the density increment at constant chemical potential of all diffusible solutes. The technique used eliminates any problems resulting from detergent binding to the protein, is independent of the particular detergent used (in this case the nonionic n-octyl beta-D-glucopyranoside), and gives the apparent weight-average molecular mass at different protein concentrations, allowing extrapolation to zero concentration. It means that the solutions of the complex must be brought to dialysis equilibrium with the solvent detergent solution and also requires a reliable method for measuring the protein concentration, for which amino acid analysis was used. The detergent-solubilized complex was a trimer that dissociated into monomers and dimers at low protein concentration. The accurate concentration determinations also allowed the molar chlorophyll-to-protein ratio to be measured as 15, corresponding to 8 chlorophyll a and 7 chlorophyll b molecules.
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Affiliation(s)
- P J Butler
- Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, England
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Daum B, Nicastro D, Austin J, McIntosh JR, Kühlbrandt W. Arrangement of photosystem II and ATP synthase in chloroplast membranes of spinach and pea. THE PLANT CELL 2010; 22:1299-312. [PMID: 20388855 PMCID: PMC2879734 DOI: 10.1105/tpc.109.071431] [Citation(s) in RCA: 195] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 03/03/2010] [Accepted: 03/29/2010] [Indexed: 05/17/2023]
Abstract
We used cryoelectron tomography to reveal the arrangements of photosystem II (PSII) and ATP synthase in vitreous sections of intact chloroplasts and plunge-frozen suspensions of isolated thylakoid membranes. We found that stroma and grana thylakoids are connected at the grana margins by staggered lamellar membrane protrusions. The stacking repeat of grana membranes in frozen-hydrated chloroplasts is 15.7 nm, with a 4.5-nm lumenal space and a 3.2-nm distance between the flat stromal surfaces. The chloroplast ATP synthase is confined to minimally curved regions at the grana end membranes and stroma lamellae, where it covers 20% of the surface area. In total, 85% of the ATP synthases are monomers and the remainder form random assemblies of two or more copies. Supercomplexes of PSII and light-harvesting complex II (LHCII) occasionally form ordered arrays in appressed grana thylakoids, whereas this order is lost in destacked membranes. In the ordered arrays, each membrane on either side of the stromal gap contains a two-dimensional crystal of supercomplexes, with the two lattices arranged such that PSII cores, LHCII trimers, and minor LHCs each face a complex of the same kind in the opposite membrane. Grana formation is likely to result from electrostatic interactions between these complexes across the stromal gap.
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Affiliation(s)
- Bertram Daum
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Daniela Nicastro
- Biology Department, Brandeis University, Waltham, Massachusetts 02453
| | - Jotham Austin
- Advanced Electron Microscopy Facility, University of Chicago, Chicago, Illinois 60637
| | | | - Werner Kühlbrandt
- Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
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Barros T, Kühlbrandt W. Crystallisation, structure and function of plant light-harvesting Complex II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:753-72. [DOI: 10.1016/j.bbabio.2009.03.012] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 03/12/2009] [Accepted: 03/13/2009] [Indexed: 11/15/2022]
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6
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Barros T, Royant A, Standfuss J, Dreuw A, Kühlbrandt W. Crystal structure of plant light-harvesting complex shows the active, energy-transmitting state. EMBO J 2009; 28:298-306. [PMID: 19131972 PMCID: PMC2637333 DOI: 10.1038/emboj.2008.276] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 12/03/2008] [Indexed: 11/08/2022] Open
Abstract
Plants dissipate excess excitation energy as heat by non-photochemical quenching (NPQ). NPQ has been thought to resemble in vitro aggregation quenching of the major antenna complex, light harvesting complex of photosystem II (LHC-II). Both processes are widely believed to involve a conformational change that creates a quenching centre of two neighbouring pigments within the complex. Using recombinant LHC-II lacking the pigments implicated in quenching, we show that they have no particular role. Single crystals of LHC-II emit strong, orientation-dependent fluorescence with an emission maximum at 680 nm. The average lifetime of the main 680 nm crystal emission at 100 K is 1.31 ns, but only 0.39 ns for LHC-II aggregates under identical conditions. The strong emission and comparatively long fluorescence lifetimes of single LHC-II crystals indicate that the complex is unquenched, and that therefore the crystal structure shows the active, energy-transmitting state of LHC-II. We conclude that quenching of excitation energy in the light-harvesting antenna is due to the molecular interaction with external pigments in vitro or other pigment-protein complexes such as PsbS in vivo, and does not require a conformational change within the complex.
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Affiliation(s)
- Tiago Barros
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Antoine Royant
- Laboratoire de Cristallogenèse et Cristallographie des Protéines, Institut de Biologie Structurale J-P Ebel, UMR 5075 CNRS–CEA–UJF, Grenoble, France
- European Synchrotron Radiation Facility, Grenoble, France
| | - Jörg Standfuss
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Andreas Dreuw
- Institute for Physical and Theoretical Chemistry, Johann Wolfgang Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Werner Kühlbrandt
- Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
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7
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Standfuss J, Terwisscha van Scheltinga AC, Lamborghini M, Kühlbrandt W. Mechanisms of photoprotection and nonphotochemical quenching in pea light-harvesting complex at 2.5 A resolution. EMBO J 2005; 24:919-28. [PMID: 15719016 PMCID: PMC554132 DOI: 10.1038/sj.emboj.7600585] [Citation(s) in RCA: 578] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2004] [Accepted: 01/26/2005] [Indexed: 11/08/2022] Open
Abstract
The plant light-harvesting complex of photosystem II (LHC-II) collects and transmits solar energy for photosynthesis in chloroplast membranes and has essential roles in regulation of photosynthesis and in photoprotection. The 2.5 A structure of pea LHC-II determined by X-ray crystallography of stacked two-dimensional crystals shows how membranes interact to form chloroplast grana, and reveals the mutual arrangement of 42 chlorophylls a and b, 12 carotenoids and six lipids in the LHC-II trimer. Spectral assignment of individual chlorophylls indicates the flow of energy in the complex and the mechanism of photoprotection in two close chlorophyll a-lutein pairs. We propose a simple mechanism for the xanthophyll-related, slow component of nonphotochemical quenching in LHC-II, by which excess energy is transferred to a zeaxanthin replacing violaxanthin in its binding site, and dissipated as heat. Our structure shows the complex in a quenched state, which may be relevant for the rapid, pH-induced component of nonphotochemical quenching.
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Affiliation(s)
- Jörg Standfuss
- Max Planck Institute of Biophysics, Department of Structural Biology, Frankfurt am Main, Germany
| | | | - Matteo Lamborghini
- Max Planck Institute of Biophysics, Department of Structural Biology, Frankfurt am Main, Germany
| | - Werner Kühlbrandt
- Max Planck Institute of Biophysics, Department of Structural Biology, Frankfurt am Main, Germany
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8
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Massover WH. A low-dose electron diffraction assay for protection of protein structure against damage from drying. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2004; 10:261-269. [PMID: 15306051 DOI: 10.1017/s1431927604040073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2002] [Indexed: 05/24/2023]
Abstract
A new assay using low-dose electron diffraction to measure the protection of protein structure against damage from drying is described. When thin single crystals of catalase are dried within water alone, low-dose electron diffraction yields no Bragg spots. Drying within an experimental aqueous solution that permits detection of diffraction spots thereby indicates a positive result, and the extent of these Bragg reflections into the high angle range gives a quantitative measure of the degree of protection. Bragg spots out to 3.73.9 are recorded for drying within 100 mM solutions of the known structure-preserving sugars, sucrose, tannin, and trehalose. The ability of trehalose to maintain native protein structure during drying starts between 10 and 25 mM, and changes only slightly at concentrations above this threshold; with drying in 150-mM trehalose, catalase crystals yield diffraction spots out to 3.7. Drying within the organic nonsugar polymer polyvinylpyrrolidone gives Bragg spots to 4.0. This new assay should be useful to measure the unexamined structure-preserving capabilities of modified sugars, other nonsugars, and mixtures to identify which protective matrix maintains native protein structure to the greatest extent during drying; electron crystallography using that optimal matrix should yield protein structure at improved levels of high resolution.
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Affiliation(s)
- William H Massover
- Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ 07101-1709, USA.
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9
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Lemieux MJ, Song J, Kim MJ, Huang Y, Villa A, Auer M, Li XD, Wang DN. Three-dimensional crystallization of the Escherichia coli glycerol-3-phosphate transporter: a member of the major facilitator superfamily. Protein Sci 2003; 12:2748-56. [PMID: 14627735 PMCID: PMC2366983 DOI: 10.1110/ps.03276603] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Revised: 09/05/2003] [Accepted: 09/11/2003] [Indexed: 10/26/2022]
Abstract
Here we report the successful three-dimensional crystallization of GlpT, the glycerol-3-phosphate transporter from Escherichia coli inner membrane. GlpT possesses 12 transmembrane alpha-helices and is a member of the major facilitator superfamily. It mediates the exchange of glycerol-3-phosphate for inorganic phosphate across the membrane. Approximately 20 phospholipid molecules per protein, identified as negatively charged phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin, were required for the monodispersity of purified GlpT. Analytical size-exclusion chromatography proved to be efficient in identifying detergents for GlpT monodispersity. Nine such detergents were later used for GlpT crystallization. Screening for crystal nucleation was carried out with a variety of polyethylene glycols as the precipitant over a wide pH range. Subsequent identification of a rigid protein core by limited proteolysis and mass spectroscopy resulted in better-ordered crystals. These crystals exhibited order to 3.7 A resolution in two dimensions. However, the stacking in the third dimension was partially disordered. This stacking problem was overcome by using a detergent mixture and manipulating the ionic interactions in the crystallization solution. The resulting GlpT crystals diffracted isotropically to 3.3 A resolution and were suitable for structure determination by X-ray crystallography.
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Affiliation(s)
- M Joanne Lemieux
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University School of Medicine, New York, New York 10016, USA
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10
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Jackowski G, Pielucha K. Heterogeneity of the main light-harvesting chlorophyll a/b-protein complex of photosystem II (LHCII) at the level of trimeric subunits. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2001; 64:45-54. [PMID: 11705729 DOI: 10.1016/s1011-1344(01)00188-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To study organization of the main light-harvesting chlorophyll a/b-protein complex of photosystem II (LHCII) from spinach thylakoid membranes at the level of trimeric subcomplexes, we have applied non-denaturing isoelectric focusing (ndIEF) in vertical, slab polyacrylamide gels. When analyzed by two consecutive ndIEF/electroelution runs, spinach BBY membrane preparations (PSII(alpha)-enriched, stacked thylakoid membranes) were resolved into nine fractions of 100% purity, labelled 1-9 in order of decreasing pI values. Seven of these fractions (3-9) were shown by absorption spectroscopy to stand for LHCII subcomplexes. The subcomplexes were established - by monitoring their circular dichroism spectra and comparing them to the spectra of native LHCII trimers and monomers - to be structurally intact trimers. The analysis of polypeptide composition of the subcomplexes in terms of apparent molecular masses and Lhcb genes' products led us to the conclusion that each of the subcomplexes might be a mixed population of closely similar individual trimers, comprising of permutations of Lhcb1 and Lhcb2 (subcomplexes 3-7) or Lhcb1, Lhcb2 and Lhcb3 (subcomplexes 8 and 9).
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Affiliation(s)
- G Jackowski
- Department of Plant Physiology, Faculty of Biology, Adam Mickiewicz University, Al. Niepodleglosci 14, 61-713, Poznan, Poland.
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11
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Timmins P, Leonhard M, Weltzien H, Wacker T, Welte W. A physical characterization of some detergents of potential use for membrane protein crystallization. FEBS Lett 2001. [DOI: 10.1016/0014-5793(88)80513-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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12
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Ford RC, Pauptit RA, Holzenburg A. Structural studies on improved crystals of the photosystem I reaction centre from Phormidium laminosum. FEBS Lett 2001. [DOI: 10.1016/0014-5793(88)80517-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Kühlbrandt W, Becker A, Mäntele W. Chlorophyll dichroism of three-dimensional crystals of the light-harvesting chlorophyll a
/b
-protein complex. FEBS Lett 2001. [DOI: 10.1016/0014-5793(88)81438-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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14
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Lin S, Knox RS. Applications of a CP-II model to excitation transfer experiments on light-harvesting chlorophylla/b-protein complexes. FEBS Lett 2001. [DOI: 10.1016/0014-5793(88)80785-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Takeda K, Sato H, Hino T, Kono M, Fukuda K, Sakurai I, Okada T, Kouyama T. A novel three-dimensional crystal of bacteriorhodopsin obtained by successive fusion of the vesicular assemblies. J Mol Biol 1998; 283:463-74. [PMID: 9769218 DOI: 10.1006/jmbi.1998.2103] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When the two-dimensional crystal of bacteriorhodopsin (bR), purple membrane, is incubated at high temperature (32 degreesC) with a small amount of the neutral detergent octylthioglucoside in the presence of the precipitant ammonium sulfate, a large fraction of the membrane fragments is converted into spherical vesicles with a diameter of 50 nm, which are able to assemble into optically isotropic hexagonal crystals when the precipitant concentration is increased. The vesicularization of purple membrane takes place under such a condition that the miscibility of the detergent to the aqueous phase becomes very low, and we suggest that it is initiated by insertion of the detergent molecules into the membrane. At low temperature, the transformation into the vesicular structure is inhibited and no large crystal is produced directly from membrane/detergent/precipitant mixtures. When a suspension of the spherical vesicles produced at the high temperature is cooled and concentrated below 15 degreesC, however, a birefringent hexagonal crystal is produced that diffracts X-rays beyond 2.5 A resolution. This new crystal belongs to the space group P622 with unit cell dimensions of a=b=104.7 A and c=114.1 A, and it is shown to be made up of stacked planar membranes, in each of which the bR trimers are arranged on a honeycomb lattice and the space among the proteins is filled with the detergent molecules and native lipids. These stacked membranes are suggested to be produced by successive fusion of the spherical vesicles. This implies that the crystallization is achieved without any step for complete solubilization of the protein. The present result offers a unique crystallization method that may be applicable to such membrane proteins that are liable to denature in the presence of an excess amount of detergent.
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Affiliation(s)
- K Takeda
- Graduate School of Science, Nagoya University, Nagoya, 464-8602, Japan
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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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17
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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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18
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Furuichi M, Nishimoto E, Koga T, Takase A, Yamashita S. Detergent effects on the light-harvesting chlorophyll A/B-protein complex crystallization revealed by fluorescence depolarization. Biochem Biophys Res Commun 1997; 233:555-8. [PMID: 9144576 DOI: 10.1006/bbrc.1997.6429] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Detergent effects on the pre-crystallization of light-harvesting chlorophyll a/b-protein complex (LHCII) were investigated through the fluorescence depolarization method. Stable LHCII crystals were formed in the media containing Triton X-100 (TX) or n-nonyl-beta-D-glucopyranoside (NG) and the crystallization efficients were dependent on their concentrations. The second virial coefficient of crystallizing system, estimated by the fluorescence depolarization analysis of LHCII, showed the most harmonious value under the condition yielding the most efficient crystallization of LHCII to suggest that some specific molecular interaction leading to the crystal growth would be induced according to the concentration of TX or NG.
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Affiliation(s)
- M Furuichi
- Faculty of Agriculture, Institute of Biophysics, Kyushu University, Higashi-ku, Fukuoka, Japan
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19
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Three-dimensional crystallization of the light-harvesting complex from Mantoniella squamata (Prasinophyceae) requires an adequate purification procedure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1995. [DOI: 10.1016/0005-2728(95)00085-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Jackowski G, Przymusiński R. The resolution and biochemical characterization of subcomplexes of the main light-harvesting chlorophyll a/b-protein complex of Photosystem II (LHC II). PHOTOSYNTHESIS RESEARCH 1995; 43:41-48. [PMID: 24306638 DOI: 10.1007/bf00029461] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/1994] [Accepted: 12/15/1994] [Indexed: 06/02/2023]
Abstract
LHC II isolated from carnation leaves has been solubilized and resolved by a newly developed, vertical-bed non-denaturing isoelectric focusing in polyacrylamide slab gels to yield three trimeric subcomplexes focusing at pH 4.52, 4.42 and 4.37 (designated a, b and c, respectively), comprising approximately 38%, 24% and 38% of the chlorophyll. The spectroscopic data demonstrated a close similarity among LHC II subcomplexes concerning their chlorophyll content and organization. The most alkaline and the most acidic subcomplex contained the 27 kDa polypeptide of LHC II while the intermediate pI fraction contained both LHC II polypeptides, i.e. 27 kDa and 26 kDa ones associated at 2:1 stoichiometry. The 27 kDa polypeptide could be resolved by denaturing isoelectrofocusing into 10 pI molecular isoforms covering 5.90-4.20 pH range. Three of the isoforms were found in the subcomplexes a and b and eight in the subcomplex c. The 26 kDa polypeptide comprised the unique pI molecular isoform focusing at pH 5.61.
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Affiliation(s)
- G Jackowski
- Department of Plant Physiology, Adam Mickiewicz University, Al. Niepodleglości 14, 61-713, Poznań, Poland
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21
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Pålsson LO, Spangfort MD, Gulbinas V, Gillbro T. Ultrafast chlorophyll b-chlorophyll a excitation energy transfer in the isolated light harvesting complex, LHC II, of green plants. Implications for the organisation of chlorophylls. FEBS Lett 1994; 339:134-8. [PMID: 8313962 DOI: 10.1016/0014-5793(94)80400-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The excitation energy transfer between chlorophyll b (Chl b) and chlorophyll a (Chl a) in the isolated trimeric chlorophyll-a/b-binding protein complex of spinach photosystem 2 (LHC II) has been studied by femtosecond spectroscopy. In the main absorption band of Chl b the ground state recovery consists of two components of 0.5 ps and 2.0 ps, respectively. Also in the Chl a absorption band, at 665 nm, the ground state recovery is essentially bi-exponential. In this case is, however, the fastest relaxation lifetime is a 2.0 ps component followed by a slower component with a lifetime in the order of 10-20 ps. In the Chl b absorption band a more or less constant anisotropy of r = 0.2 was observed during the 3 ps the system was monitored. In the Chl a absorption band there was, however, a relaxation of the anisotropy from r = 0.3 to a quasi steady state level of r = 0.18 in about 1 ps. Since the 0.5 ps component is only seen upon selective excitation of Chl b we assign this component to the energy transfer between Chl b and Chl a. The other components most likely represents redistribution processes of energy among spectrally different forms of Chl a. The energy transfer process between Chl b and Chl a can well be explained by the Förster mechanism which also gives a calculated distance of 13 A between interacting chromophores. The organisation of chlorophylls in LHC II is discussed in view of the recent crystal structure data (1991) Nature 350, 130].
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Affiliation(s)
- L O Pålsson
- Department of Physical Chemistry, University of Umeå, Sweden
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23
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Arvidsson PO, Bratt CE, Andréasson LE, Kerlund HE. The 28 kDa apoprotein of CP 26 in PS II binds copper. PHOTOSYNTHESIS RESEARCH 1993; 37:217-225. [PMID: 24317802 DOI: 10.1007/bf00032825] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/1993] [Accepted: 06/29/1993] [Indexed: 06/02/2023]
Abstract
Photosystem II (PS II) particles isolated from spinach in the presence of 10 μM CuSO4 contained 1.2 copper/300 Chl that was resistant to EDTA. When CuSO4 was not added during the isolation, PS II particles contained variable amounts of copper resistant to EDTA (0.1-1.1 copper/300 Chl). No correlation was found between copper content and oxygen evolving capacity of the PS II particles. To identify the copper binding protein, we developed a fractionation procedure which included solubilisation of PS II particles followed by precipitation with polyethylene glycol. A 22-fold purification of copper with respect to protein was achieved for a 28 kDa protein. Partial amino acid sequence of a 13 kDa fragment, obtained after V8 (endo Glu-C) protease treatment, showed identity with CP 26 over a 14 amino acid stretch. EPR measurements on the purified protein suggest oxygen and/or nitrogen as ligands for copper but tend to exclude sulfur. We conclude that the 28 kDa apoprotein of CP 26 from spinach binds one copper per molecule of CP 26. A possible function for this copper protein in the xanthophyll cycle is discussed.
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Affiliation(s)
- P O Arvidsson
- Plant Biochemistry, University of Lund, POB 7007, S-220 07, Lund, Sweden
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24
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Chlorosomes, photosynthetic antennae with novel self-organized pigment structures. J Photochem Photobiol A Chem 1992. [DOI: 10.1016/1010-6030(92)85032-p] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Abstract
In spite of several great breakthroughs, the overall rate of progress in determining high-resolution structures of membrane proteins has been slow. This is entirely due to the scarcity of suitable, well-ordered crystals. Most membrane proteins are multimeric complexes with a composite molecular mass in excess of 50000 Da which puts them outside the range of current solution NMR techniques. For the foreseeable future, detailed information about the structure of large membrane proteins will therefore depend on crystallographic methods.
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26
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Allen JF. Protein phosphorylation in regulation of photosynthesis. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1098:275-335. [PMID: 1310622 DOI: 10.1016/s0005-2728(09)91014-3] [Citation(s) in RCA: 499] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- J F Allen
- Department of Biology, University of Oslo, Blindern, Norway
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Kubota T, Kawamoto M, Fukuyama K, Shinzawa-Itoh K, Yoshikawa S, Matsubara H. Crystallization and preliminary X-ray crystallographic studies of bovine heart mitochondrial cytochrome bc1 complex. J Mol Biol 1991; 221:379-82. [PMID: 1656052 DOI: 10.1016/0022-2836(91)80059-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cytochrome bc1 complex (ubiquinol:ferricytochrome c oxidoreductase, EC. 1.10.2.2) from bovine heart mitochondria was crystallized by a batchwise method from protein solution containing sucrose monolaurate using polyethylene glycol-4000 as a precipitant. The red parallelepiped crystals grew to a size of approximately 1 mm x 1 mm x 1 mm. The crystalline protein showed enzymic activity catalyzing electron transfer from ubiquinol-2 to cytochrome c. The subunit composition and absorption spectrum of the crystalline enzyme were identical to those reported previously for the enzyme in solution. The crystal diffracted X-rays to 7.5 A resolution. The diffraction pattern indicated a monoclinic form, space group P2(1), and unit-cell constants of a = 196 A, b = 179 A, c = 253 A and beta = 97 degrees. Most probably four functional units are present in an asymmetric unit.
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Affiliation(s)
- T Kubota
- Department of Biology, Faculty of Science, Osaka University, Japan
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28
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Spangford M, Andersson B. Subpopulations of the main chlorophyll a/b light-harvesting complex of Photosystem II—isolation and biochemical characterization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1989. [DOI: 10.1016/s0005-2728(89)80067-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Holzwarth AR. Applications of ultrafast laser spectroscopy for the study of biological systems. Q Rev Biophys 1989; 22:239-326. [PMID: 2695961 DOI: 10.1017/s0033583500002985] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The discovery of mode-locked laser operation now nearly two decades ago has started a development which enables researchers to probe the dynamics of ultrafast physical and chemical processes at the molecular level on shorter and shorter time scales. Naturally the first applications were in the fields of photophysics and photochemistry where it was then possible for the first time to probe electronic and vibrational relaxation processes on a sub-nanosecond timescale. The development went from lasers producing pulses of many picoseconds to the shortest pulses which are at present just a few femtoseconds long. Soon after their discovery ultrashort pulses were applied also to biological systems which has revealed a wealth of information contributing to our understanding of a broadrange of biological processes on the molecular level.It is the aim of this review to discuss the recent advances and point out some future trends in the study of ultrafast processes in biological systems using laser techniques. The emphasis will be mainly on new results obtained during the last 5 or 6 years. The term ultrafast means that I shall restrict myself to sub-nanosecond processes with a few exceptions.
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Affiliation(s)
- A R Holzwarth
- Max-Planck-Institut für Strahlenchemie, Mülheim/Ruhr, FRG
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30
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Kühlbrandt W, Downing KH. Two-dimensional structure of plant light-harvesting complex at 3.7 A [corrected] resolution by electron crystallography. J Mol Biol 1989; 207:823-8. [PMID: 2760931 DOI: 10.1016/0022-2836(89)90247-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The structure of the light-harvesting chlorophyll a/b-protein complex has been determined at 3.7 A resolution in projection by electron diffraction, electron microscopy and image analysis. Diffraction patterns and high-resolution spotscan images of two-dimensional crystals stabilized with tannin were recorded at low temperature. Phases of structure factors were obtained directly by image processing, after correction of the images for lattice distortions, defocus and beam tilt. Amplitudes were measured by electron diffraction. The projection map shows the detailed structure of the trimeric complex, suggesting the positions of two domains of potential structural and functional homology, of one membrane-spanning alpha-helix approximately perpendicular to the membrane plane and of several tightly bound lipid molecules.
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Affiliation(s)
- W Kühlbrandt
- European Molecular Biology Laboratory, Heidelberg, West Germany
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31
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Abstract
As recently as 10 years ago, the prospect of solving the structure of any membrane protein by X-ray crystallography seemed remote. Since then, the threedimensional (3-D) structures of two membrane protein complexes, the bacterial photosynthetic reaction centres ofRhodopseudomonas viridis(Deisenhoferet al.1984, 1985) and ofRhodobacter sphaeroides(Allenet al.1986, 1987a, 6; Changet al.1986) have been determined at high resolution. This astonishing progress would not have been possible without the pioneering work of Michel and Garavito who first succeeded in growing 3-D crystals of the membrane proteins bacteriorhodopsin (Michel & Oesterhelt, 1980) and matrix porin (Garavito & Rosenbusch, 1980). X-ray crystallography is still the only routine method for determining the 3-D structures of biological macromolecules at high resolution and well-ordered 3-D crystals of sufficient size are the essential prerequisite.
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Affiliation(s)
- W Kühlbrandt
- Department of Physics, Imperial College, London, England
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32
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Kühlbrandt W. Structure of light-harvesting chlorophyll a/b protein complex from plant photosynthetic membranes at 7 A resolution in projection. J Mol Biol 1988; 202:849-64. [PMID: 3050133 DOI: 10.1016/0022-2836(88)90563-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The structure of thin three-dimensional crystals of the light-harvesting chlorophyll a/b protein complex, an integral membrane protein from the photosynthetic membrane of chloroplasts, has been determined at 7 A (1 A = 0.1 nm) resolution in projection. The structure analysis was carried out by image processing of low-dose electron micrographs, and electron diffraction of thin three-dimensional crystals preserved in tannin. The three-dimensional crystals appeared to be stacks of two-dimensional crystals having p321 symmetry. Results of the image analysis indicated that the crystals were disordered, due to random translational displacement of stacked layers. This was established by a translation search routine that used the low-resolution projection of a single layer as a reference. The reference map was derived from the symmetrized average of two images that showed features consistent with the projected structure of negatively stained two-dimensional crystals. The phase shift resulting from the displacement of each layer was corrected. Phase shifts were then refined by minimizing the phase residual, bringing all layers to the same phase origin. Refined phases from different images were in agreement and reliable to 7 A resolution. A projection map was generated from the averaged phases and electron diffraction amplitudes. The map showed that the complex was a trimer composed of three protein monomers related by 3-fold symmetry. The projected density within the protein monomer suggested membrane-spanning alpha-helices roughly perpendicular to the crystal plane. The density in the centre and on the periphery of the trimeric complex was lower than that of the protein, indicating that this region contained low-density matter, such as lipids and antenna chlorophylls.
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Affiliation(s)
- W Kühlbrandt
- Blackett Laboratory, Department of Pure and Applied Biology, Imperial College of Science and Technology, London, England
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Kühlbrandt W, Barber J. Separation of phosphorylated and unphosphorylated light-harvesting chlorophyll ab-protein complex by column chromatography. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1988. [DOI: 10.1016/0005-2728(88)90126-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Chitnis PR, Thornber JP. The major light-harvesting complex of Photosystem II: aspects of its molecular and cell biology. PHOTOSYNTHESIS RESEARCH 1988; 16:41-63. [PMID: 24430991 DOI: 10.1007/bf00039485] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/1987] [Accepted: 11/30/1987] [Indexed: 06/03/2023]
Abstract
The light-harvesting complex of photosystem II (LHC II) contains one major (LHC IIb) and at least three minor chlorophyll-protein components. The apoproteins of LHC IIb (LHCP) are encoded by nuclear genes and synthesized in the cytoplasm as a higher molecular weight precursor(s) (pLHCP). Several genes coding for pLHCP have been cloned from various higher plant species. The expression of these genes is dependent upon a variety of factors such as light, the developmental stage of the plastids and the plant. After its synthesis in the cytoplasm, pLHCP is imported into plastids, inserted into thylakoids, processed to its mature form, and assembled into LHC IIb. The pathway of assembly of LHC IIb in the thylakoid membranes is currently being investigated in several laboratories. We present a model that gives some details of the steps in the assembly process. Many of the steps involved in the synthesis and assembly are dependent on light and the stage of plastid development.
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Affiliation(s)
- P R Chitnis
- Biology Department and Molecular Biology Institute, University of California, 90024, Los Angeles, CA, USA
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35
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Abstract
PhoE porin has been reconstituted with phospholipid, forming large membrane patches. Electron diffraction shows that the reconstituted PhoE porin forms highly coherent crystalline arrays, giving structural information to a resolution of 3.4 A. The crystal form is of the orthorhombic space group P2(1)2(1)2, with unit cell dimensions a = 150 A and b = 129 A. Images of negatively stained PhoE crystalline patches show that there are four PhoE porin trimers in a unit cell.
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Affiliation(s)
- B K Jap
- Donner Laboratory, Lawrence Berkeley Laboratory, University of California, Berkeley 94720
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