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Okhrimenko IS, Kovalev K, Petrovskaya LE, Ilyinsky NS, Alekseev AA, Marin E, Rokitskaya TI, Antonenko YN, Siletsky SA, Popov PA, Zagryadskaya YA, Soloviov DV, Chizhov IV, Zabelskii DV, Ryzhykau YL, Vlasov AV, Kuklin AI, Bogorodskiy AO, Mikhailov AE, Sidorov DV, Bukhalovich S, Tsybrov F, Bukhdruker S, Vlasova AD, Borshchevskiy VI, Dolgikh DA, Kirpichnikov MP, Bamberg E, Gordeliy VI. Mirror proteorhodopsins. Commun Chem 2023; 6:88. [PMID: 37130895 PMCID: PMC10154332 DOI: 10.1038/s42004-023-00884-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 04/12/2023] [Indexed: 05/04/2023] Open
Abstract
Proteorhodopsins (PRs), bacterial light-driven outward proton pumps comprise the first discovered and largest family of rhodopsins, they play a significant role in life on the Earth. A big remaining mystery was that up-to-date there was no described bacterial rhodopsins pumping protons at acidic pH despite the fact that bacteria live in different pH environment. Here we describe conceptually new bacterial rhodopsins which are operating as outward proton pumps at acidic pH. A comprehensive function-structure study of a representative of a new clade of proton pumping rhodopsins which we name "mirror proteorhodopsins", from Sphingomonas paucimobilis (SpaR) shows cavity/gate architecture of the proton translocation pathway rather resembling channelrhodopsins than the known rhodopsin proton pumps. Another unique property of mirror proteorhodopsins is that proton pumping is inhibited by a millimolar concentration of zinc. We also show that mirror proteorhodopsins are extensively represented in opportunistic multidrug resistant human pathogens, plant growth-promoting and zinc solubilizing bacteria. They may be of optogenetic interest.
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Affiliation(s)
- Ivan S Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | | | - Lada E Petrovskaya
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
| | - Nikolay S Ilyinsky
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Alexey A Alekseev
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Egor Marin
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Tatyana I Rokitskaya
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Sergey A Siletsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Petr A Popov
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- iMolecule, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Yuliya A Zagryadskaya
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | | | - Igor V Chizhov
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | | | - Yury L Ryzhykau
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Alexey V Vlasov
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Alexander I Kuklin
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Andrey O Bogorodskiy
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Anatolii E Mikhailov
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Daniil V Sidorov
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Siarhei Bukhalovich
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Fedor Tsybrov
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Sergey Bukhdruker
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Anastasiia D Vlasova
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Valentin I Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, Russia
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Dmitry A Dolgikh
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
- Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Mikhail P Kirpichnikov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
- Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Ernst Bamberg
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Valentin I Gordeliy
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CNRS, CEA, Grenoble, France.
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2
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True-atomic-resolution insights into the structure and functional role of linear chains and low-barrier hydrogen bonds in proteins. Nat Struct Mol Biol 2022; 29:440-450. [PMID: 35484235 DOI: 10.1038/s41594-022-00762-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/14/2022] [Indexed: 12/21/2022]
Abstract
Hydrogen bonds are fundamental to the structure and function of biological macromolecules and have been explored in detail. The chains of hydrogen bonds (CHBs) and low-barrier hydrogen bonds (LBHBs) were proposed to play essential roles in enzyme catalysis and proton transport. However, high-resolution structural data from CHBs and LBHBs is limited. The challenge is that their 'visualization' requires ultrahigh-resolution structures of the ground and functionally important intermediate states to identify proton translocation events and perform their structural assignment. Our true-atomic-resolution structures of the light-driven proton pump bacteriorhodopsin, a model in studies of proton transport, show that CHBs and LBHBs not only serve as proton pathways, but also are indispensable for long-range communications, signaling and proton storage in proteins. The complete picture of CHBs and LBHBs discloses their multifunctional roles in providing protein functions and presents a consistent picture of proton transport and storage resolving long-standing debates and controversies.
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Abstract
Microbial rhodopsins are light-sensitive transmembrane proteins, evolutionary adapted by various organisms like archaea, bacteria, simple eukaryote, and viruses to utilize solar energy for their survival. A complete understanding of functional mechanisms of these proteins is not possible without the knowledge of their high-resolution structures, which can be primarily obtained by X-ray crystallography. This technique, however, requires high-quality crystals, growing of which is a great challenge especially in case of membrane proteins. In this chapter, we summarize methods applied for crystallization of microbial rhodopsins with the emphasis on crystallization in lipidic mesophases, also known as in meso approach. In particular, we describe in detail the methods of crystallization using lipidic cubic phase to grow both large crystals optimized for traditional crystallographic data collection and microcrystals for serial crystallography.
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Affiliation(s)
- Kirill Kovalev
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
- Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich GmbH, Jülich, Germany
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
- Institute of Crystallography, University of Aachen (RWTH), Aachen, Germany
| | - Roman Astashkin
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Valentin Gordeliy
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Vadim Cherezov
- Bridge Institute, Department of Chemistry, University of Southern California, Los Angeles, CA, USA.
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4
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Polovinkin V, Khakurel K, Babiak M, Angelov B, Schneider B, Dohnalek J, Andreasson J, Hajdu J. Demonstration of electron diffraction from membrane protein crystals grown in a lipidic mesophase after lamella preparation by focused ion beam milling at cryogenic temperatures. J Appl Crystallogr 2020; 53:1416-1424. [PMID: 33304220 PMCID: PMC7710488 DOI: 10.1107/s1600576720013096] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 09/27/2020] [Indexed: 12/26/2022] Open
Abstract
Electron diffraction experiments on crystals of membrane proteins grown in lipidic mesophases have not been possible owing to a thick layer of viscous crystallization medium around the crystals. Here it is shown that focused ion beam milling at cryogenic temperatures (cryo-FIB milling) can remove the viscous layer, and high-quality electron diffraction on a FIB-milled lamella of a bacteriorhodopsin 3D crystal is demonstrated. Electron crystallography of sub-micrometre-sized 3D protein crystals has emerged recently as a valuable field of structural biology. In meso crystallization methods, utilizing lipidic mesophases, particularly lipidic cubic phases (LCPs), can produce high-quality 3D crystals of membrane proteins (MPs). A major step towards realizing 3D electron crystallography of MP crystals, grown in meso, is to demonstrate electron diffraction from such crystals. The first task is to remove the viscous and sticky lipidic matrix that surrounds the crystals without damaging the crystals. Additionally, the crystals have to be thin enough to let electrons traverse them without significant multiple scattering. In the present work, the concept that focused ion beam milling at cryogenic temperatures (cryo-FIB milling) can be used to remove excess host lipidic mesophase matrix is experimentally verified, and then the crystals are thinned to a thickness suitable for electron diffraction. In this study, bacteriorhodopsin (BR) crystals grown in a lipidic cubic mesophase of monoolein were used as a model system. LCP from a part of a hexagon-shaped plate-like BR crystal (∼10 µm in thickness and ∼70 µm in the longest dimension), which was flash-frozen in liquid nitrogen, was milled away with a gallium FIB under cryogenic conditions, and a part of the crystal itself was thinned into a ∼210 nm-thick lamella with the ion beam. The frozen sample was then transferred into an electron cryo-microscope, and a nanovolume of ∼1400 × 1400 × 210 nm of the BR lamella was exposed to 200 kV electrons at a fluence of ∼0.06 e Å−2. The resulting electron diffraction peaks were detected beyond 2.7 Å resolution (with an average peak height to background ratio of >2) by a CMOS-based Ceta 16M camera. The results demonstrate that cryo-FIB milling produces high-quality lamellae from crystals grown in lipidic mesophases and pave the way for 3D electron crystallography on crystals grown or embedded in highly viscous media.
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Affiliation(s)
- Vitaly Polovinkin
- ELI Beamlines, Institute of Physics, Czech Academy of Science, Na Slovance 2, 18221 Prague, Czech Republic
| | - Krishna Khakurel
- ELI Beamlines, Institute of Physics, Czech Academy of Science, Na Slovance 2, 18221 Prague, Czech Republic
| | - Michal Babiak
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5/4, 62500 Brno, Czech Republic
| | - Borislav Angelov
- ELI Beamlines, Institute of Physics, Czech Academy of Science, Na Slovance 2, 18221 Prague, Czech Republic
| | - Bohdan Schneider
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, CZ-252 50 Vestec, Czech Republic
| | - Jan Dohnalek
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, CZ-252 50 Vestec, Czech Republic
| | - Jakob Andreasson
- ELI Beamlines, Institute of Physics, Czech Academy of Science, Na Slovance 2, 18221 Prague, Czech Republic
| | - Janos Hajdu
- ELI Beamlines, Institute of Physics, Czech Academy of Science, Na Slovance 2, 18221 Prague, Czech Republic.,Department of Cell and Molecular Biology, Uppsala University, Husargatan 3 (Box 596), SE-751 24 Uppsala, Sweden
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5
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Stauffer M, Hirschi S, Ucurum Z, Harder D, Schlesinger R, Fotiadis D. Engineering and Production of the Light-Driven Proton Pump Bacteriorhodopsin in 2D Crystals for Basic Research and Applied Technologies. Methods Protoc 2020; 3:mps3030051. [PMID: 32707904 PMCID: PMC7563565 DOI: 10.3390/mps3030051] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/18/2020] [Accepted: 07/19/2020] [Indexed: 11/16/2022] Open
Abstract
The light-driven proton pump bacteriorhodopsin (BR) from the extreme halophilic archaeon Halobacterium salinarum is a retinal-binding protein, which forms highly ordered and thermally stable 2D crystals in native membranes (termed purple membranes). BR and purple membranes (PMs) have been and are still being intensively studied by numerous researchers from different scientific disciplines. Furthermore, PMs are being successfully used in new, emerging technologies such as bioelectronics and bionanotechnology. Most published studies used the wild-type form of BR, because of the intrinsic difficulty to produce genetically modified versions in purple membranes homologously. However, modification and engineering is crucial for studies in basic research and, in particular, to tailor BR for specific applications in applied sciences. We present an extensive and detailed protocol ranging from the genetic modification and cultivation of H. salinarum to the isolation, and biochemical, biophysical and functional characterization of BR and purple membranes. Pitfalls and problems of the homologous expression of BR versions in H. salinarum are discussed and possible solutions presented. The protocol is intended to facilitate the access to genetically modified BR versions for researchers of different scientific disciplines, thus increasing the application of this versatile biomaterial.
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Affiliation(s)
- Mirko Stauffer
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Stephan Hirschi
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Zöhre Ucurum
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Daniel Harder
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
| | - Ramona Schlesinger
- Department of Physics, Genetic Biophysics, Freie Universität Berlin, 14195 Berlin, Germany
- Correspondence: (R.S.); (D.F.)
| | - Dimitrios Fotiadis
- Institute of Biochemistry and Molecular Medicine, and Swiss National Centre of Competence in Research (NCCR) TransCure, University of Bern, 3012 Bern, Switzerland; (M.S.); (S.H.); (Z.U.); (D.H.)
- Correspondence: (R.S.); (D.F.)
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6
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Kovalev K, Volkov D, Astashkin R, Alekseev A, Gushchin I, Haro-Moreno JM, Chizhov I, Siletsky S, Mamedov M, Rogachev A, Balandin T, Borshchevskiy V, Popov A, Bourenkov G, Bamberg E, Rodriguez-Valera F, Büldt G, Gordeliy V. High-resolution structural insights into the heliorhodopsin family. Proc Natl Acad Sci U S A 2020; 117:4131-4141. [PMID: 32034096 PMCID: PMC7049168 DOI: 10.1073/pnas.1915888117] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Rhodopsins are the most abundant light-harvesting proteins. A new family of rhodopsins, heliorhodopsins (HeRs), has recently been discovered. Unlike in the known rhodopsins, in HeRs the N termini face the cytoplasm. The function of HeRs remains unknown. We present the structures of the bacterial HeR-48C12 in two states at the resolution of 1.5 Å, which highlight its remarkable difference from all known rhodopsins. The interior of HeR's extracellular part is completely hydrophobic, while the cytoplasmic part comprises a cavity (Schiff base cavity [SBC]) surrounded by charged amino acids and containing a cluster of water molecules, presumably being a primary proton acceptor from the Schiff base. At acidic pH, a planar triangular molecule (acetate) is present in the SBC. Structure-based bioinformatic analysis identified 10 subfamilies of HeRs, suggesting their diverse biological functions. The structures and available data suggest an enzymatic activity of HeR-48C12 subfamily and their possible involvement in fundamental redox biological processes.
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Affiliation(s)
- K Kovalev
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-Commission for Atomic Energy (CEA)-CNRS, 38000 Grenoble, France
- Institute of Biological Information Processing (Institute of Biological Information Processing: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
- Institute of Crystallography, University of Aachen (Rheinisch-Westfälische Technische Hochschule Aachen [RWTH]), 52062 Aachen, Germany
| | - D Volkov
- Institute of Biological Information Processing (Institute of Biological Information Processing: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - R Astashkin
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-Commission for Atomic Energy (CEA)-CNRS, 38000 Grenoble, France
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
| | - A Alekseev
- Institute of Biological Information Processing (Institute of Biological Information Processing: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
- Institute of Crystallography, University of Aachen (Rheinisch-Westfälische Technische Hochschule Aachen [RWTH]), 52062 Aachen, Germany
| | - I Gushchin
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
| | - J M Haro-Moreno
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, 03202 San Juan de Alicante, Spain
| | - I Chizhov
- Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - S Siletsky
- Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - M Mamedov
- Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - A Rogachev
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna 141980, Russia
| | - T Balandin
- Institute of Biological Information Processing (Institute of Biological Information Processing: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - V Borshchevskiy
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
| | - A Popov
- Structural Biology Group, European Synchrotron Radiation Facility, 38000 Grenoble, France
| | - G Bourenkov
- Hamburg Unit care of Deutsches Elektronen-Synchrotron (DESY), European Molecular Biology Laboratory, 22607 Hamburg, Germany
| | - E Bamberg
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
- Biophysical Chemistry, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - F Rodriguez-Valera
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, 03202 San Juan de Alicante, Spain
| | - G Büldt
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
| | - V Gordeliy
- Institut de Biologie Structurale J.-P. Ebel, Université Grenoble Alpes-Commission for Atomic Energy (CEA)-CNRS, 38000 Grenoble, France;
- Institute of Biological Information Processing (Institute of Biological Information Processing: Structural Biochemistry), Forschungszentrum Jülich, 52428 Jülich, Germany
- JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich, 52428 Jülich, Germany
- Research Center for Mechanisms of Aging and Age Related Diseases, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny 141701, Russia
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7
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Volkov O, Kovalev K, Polovinkin V, Borshchevskiy V, Bamann C, Astashkin R, Marin E, Popov A, Balandin T, Willbold D, Büldt G, Bamberg E, Gordeliy V. Structural insights into ion conduction by channelrhodopsin 2. Science 2018; 358:358/6366/eaan8862. [PMID: 29170206 DOI: 10.1126/science.aan8862] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/30/2017] [Indexed: 11/02/2022]
Abstract
The light-gated ion channel channelrhodopsin 2 (ChR2) from Chlamydomonas reinhardtii is a major optogenetic tool. Photon absorption starts a well-characterized photocycle, but the structural basis for the regulation of channel opening remains unclear. We present high-resolution structures of ChR2 and the C128T mutant, which has a markedly increased open-state lifetime. The structure reveals two cavities on the intracellular side and two cavities on the extracellular side. They are connected by extended hydrogen-bonding networks involving water molecules and side-chain residues. Central is the retinal Schiff base that controls and synchronizes three gates that separate the cavities. Separate from this network is the DC gate that comprises a water-mediated bond between C128 and D156 and interacts directly with the retinal Schiff base. Comparison with the C128T structure reveals a direct connection of the DC gate to the central gate and suggests how the gating mechanism is affected by subtle tuning of the Schiff base's interactions.
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Affiliation(s)
- Oleksandr Volkov
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany
| | - Kirill Kovalev
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany.,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia.,Institute of Crystallography, University of Aachen, Aachen, Germany
| | - Vitaly Polovinkin
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany.,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia.,ELI Beamlines, Institute of Physics, Czech Academy of Sciences, 18221 Prague, Czech Republic
| | | | | | - Roman Astashkin
- Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Egor Marin
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Alexander Popov
- European Synchrotron Radiation Facility, 38027 Grenoble, France
| | - Taras Balandin
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany
| | - Dieter Willbold
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany.,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Georg Büldt
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Ernst Bamberg
- Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
| | - Valentin Gordeliy
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Juelich, Juelich, Germany. .,Institut de Biologie Structurale Jean-Pierre Ebel, Université Grenoble Alpes-Commissariat à l'Energie Atomique et aux Energies Alternatives-CNRS, Grenoble, France.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia
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8
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pH-sensitive vibrational probe reveals a cytoplasmic protonated cluster in bacteriorhodopsin. Proc Natl Acad Sci U S A 2017; 114:E10909-E10918. [PMID: 29203649 DOI: 10.1073/pnas.1707993114] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Infrared spectroscopy has been used in the past to probe the dynamics of internal proton transfer reactions taking place during the functional mechanism of proteins but has remained mostly silent to protonation changes in the aqueous medium. Here, by selectively monitoring vibrational changes of buffer molecules with a temporal resolution of 6 µs, we have traced proton release and uptake events in the light-driven proton-pump bacteriorhodopsin and correlate these to other molecular processes within the protein. We demonstrate that two distinct chemical entities contribute to the temporal evolution and spectral shape of the continuum band, an unusually broad band extending from 2,300 to well below 1,700 cm-1 The first contribution corresponds to deprotonation of the proton release complex (PRC), a complex in the extracellular domain of bacteriorhodopsin where an excess proton is shared by a cluster of internal water molecules and/or ionic E194/E204 carboxylic groups. We assign the second component of the continuum band to the proton uptake complex, a cluster with an excess proton reminiscent to the PRC but located in the cytoplasmic domain and possibly stabilized by D38. Our findings refine the current interpretation of the continuum band and call for a reevaluation of the last proton transfer steps in bacteriorhodopsin.
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9
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Laskowski PR, Pfreundschuh M, Stauffer M, Ucurum Z, Fotiadis D, Müller DJ. High-Resolution Imaging and Multiparametric Characterization of Native Membranes by Combining Confocal Microscopy and an Atomic Force Microscopy-Based Toolbox. ACS NANO 2017; 11:8292-8301. [PMID: 28745869 DOI: 10.1021/acsnano.7b03456] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To understand how membrane proteins function requires characterizing their structure, assembly, and inter- and intramolecular interactions in physiologically relevant conditions. Conventionally, such multiparametric insight is revealed by applying different biophysical methods. Here we introduce the combination of confocal microscopy, force-distance curve-based (FD-based) atomic force microscopy (AFM), and single-molecule force spectroscopy (SMFS) for the identification of native membranes and the subsequent multiparametric analysis of their membrane proteins. As a well-studied model system, we use native purple membrane from Halobacterium salinarum, whose membrane protein bacteriorhodopsin was His-tagged to bind nitrilotriacetate (NTA) ligands. First, by confocal microscopy we localize the extracellular and cytoplasmic surfaces of purple membrane. Then, we apply AFM to image single bacteriorhodopsins approaching sub-nanometer resolution. Afterwards, the binding of NTA ligands to bacteriorhodopsins is localized and quantified by FD-based AFM. Finally, we apply AFM-based SMFS to characterize the (un)folding of the membrane protein and to structurally map inter- and intramolecular interactions. The multimethodological approach is generally applicable to characterize biological membranes and membrane proteins at physiologically relevant conditions.
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Affiliation(s)
- Pawel R Laskowski
- Department of Biosystems Science and Engineering, ETH Zurich , 4058 Basel, Switzerland
| | - Moritz Pfreundschuh
- Department of Biosystems Science and Engineering, ETH Zurich , 4058 Basel, Switzerland
| | - Mirko Stauffer
- Institute of Biochemistry and Molecular Medicine, University of Bern , 3012 Bern, Switzerland
| | - Zöhre Ucurum
- Institute of Biochemistry and Molecular Medicine, University of Bern , 3012 Bern, Switzerland
| | - Dimitrios Fotiadis
- Institute of Biochemistry and Molecular Medicine, University of Bern , 3012 Bern, Switzerland
| | - Daniel J Müller
- Department of Biosystems Science and Engineering, ETH Zurich , 4058 Basel, Switzerland
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10
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Gushchin I, Melnikov I, Polovinkin V, Ishchenko A, Yuzhakova A, Buslaev P, Bourenkov G, Grudinin S, Round E, Balandin T, Borshchevskiy V, Willbold D, Leonard G, Büldt G, Popov A, Gordeliy V. Mechanism of transmembrane signaling by sensor histidine kinases. Science 2017; 356:science.aah6345. [PMID: 28522691 DOI: 10.1126/science.aah6345] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 05/08/2017] [Indexed: 11/02/2022]
Abstract
One of the major and essential classes of transmembrane (TM) receptors, present in all domains of life, is sensor histidine kinases, parts of two-component signaling systems (TCSs). The structural mechanisms of TM signaling by these sensors are poorly understood. We present crystal structures of the periplasmic sensor domain, the TM domain, and the cytoplasmic HAMP domain of the Escherichia coli nitrate/nitrite sensor histidine kinase NarQ in the ligand-bound and mutated ligand-free states. The structures reveal that the ligand binding induces rearrangements and pistonlike shifts of TM helices. The HAMP domain protomers undergo leverlike motions and convert these pistonlike motions into helical rotations. Our findings provide the structural framework for complete understanding of TM TCS signaling and for development of antimicrobial treatments targeting TCSs.
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Affiliation(s)
- Ivan Gushchin
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany. .,Moscow Institute of Physics and Technology, 141700 Dolgoprudniy, Russia
| | - Igor Melnikov
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | - Vitaly Polovinkin
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany.,Moscow Institute of Physics and Technology, 141700 Dolgoprudniy, Russia.,Univ. Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
| | - Andrii Ishchenko
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany.,Institute of Crystallography, University of Aachen (RWTH), 52056 Aachen, Germany
| | - Anastasia Yuzhakova
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany.,Moscow Institute of Physics and Technology, 141700 Dolgoprudniy, Russia
| | - Pavel Buslaev
- Moscow Institute of Physics and Technology, 141700 Dolgoprudniy, Russia
| | - Gleb Bourenkov
- European Molecular Biology Laboratory, Hamburg Outstation, 22607 Hamburg, Germany
| | - Sergei Grudinin
- Université Grenoble Alpes, LJK, F-38000 Grenoble, France.,CNRS, LJK, F-38000 Grenoble, France.,Inria, F-38000 Grenoble, France
| | - Ekaterina Round
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany.,Univ. Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
| | - Taras Balandin
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany
| | - Valentin Borshchevskiy
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany.,Moscow Institute of Physics and Technology, 141700 Dolgoprudniy, Russia
| | - Dieter Willbold
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany.,Institute of Physical Biology, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Gordon Leonard
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | - Georg Büldt
- Moscow Institute of Physics and Technology, 141700 Dolgoprudniy, Russia
| | - Alexander Popov
- European Synchrotron Radiation Facility, F-38043 Grenoble, France
| | - Valentin Gordeliy
- Institute of Complex Systems (ICS), ICS-6: Structural Biochemistry, Research Centre Jülich, 52425 Jülich, Germany. .,Moscow Institute of Physics and Technology, 141700 Dolgoprudniy, Russia.,Univ. Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
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11
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Pfreundschuh M, Harder D, Ucurum Z, Fotiadis D, Müller DJ. Detecting Ligand-Binding Events and Free Energy Landscape while Imaging Membrane Receptors at Subnanometer Resolution. NANO LETTERS 2017; 17:3261-3269. [PMID: 28361535 DOI: 10.1021/acs.nanolett.7b00941] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Force-distance curve-based atomic force microscopy has emerged into a sophisticated technique for imaging cellular membranes and for detecting specific ligand-binding events of native membrane receptors. However, so far the resolution achieved has been insufficient to structurally map ligand-binding sites onto membrane proteins. Here, we introduce experimental and theoretical approaches for overcoming this limitation. To establish a structurally and functionally well-defined reference sample, we engineer a ligand-binding site to the light-driven proton pump bacteriorhodopsin of purple membrane. Functionalizing the AFM stylus with an appropriate linker-system tethering the ligand and optimizing the AFM conditions allows for imaging the engineered bacteriorhodopsin at subnanometer resolution while structurally mapping the specific ligand-receptor binding events. Improved data analysis allows reconstructing the ligand-binding free energy landscape from the experimental data, thus providing thermodynamic and kinetic insight into the ligand-binding process. The nanoscopic method introduced is generally applicable for imaging receptors in native membranes at subnanometer resolution and for systematically mapping and quantifying the free energy landscape of ligand binding.
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Affiliation(s)
- Moritz Pfreundschuh
- Department of Biosystems Science and Engineering, ETH Zürich , 4058 Basel, Switzerland
| | - Daniel Harder
- Institute of Biochemistry and Molecular Medicine, University of Bern , 3012 Bern, Switzerland
| | - Zöhre Ucurum
- Institute of Biochemistry and Molecular Medicine, University of Bern , 3012 Bern, Switzerland
| | - Dimitrios Fotiadis
- Institute of Biochemistry and Molecular Medicine, University of Bern , 3012 Bern, Switzerland
| | - Daniel J Müller
- Department of Biosystems Science and Engineering, ETH Zürich , 4058 Basel, Switzerland
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12
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Zander U, Bourenkov G, Popov AN, de Sanctis D, Svensson O, McCarthy AA, Round E, Gordeliy V, Mueller-Dieckmann C, Leonard GA. MeshAndCollect: an automated multi-crystal data-collection workflow for synchrotron macromolecular crystallography beamlines. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2015; 71:2328-43. [PMID: 26527148 PMCID: PMC4631482 DOI: 10.1107/s1399004715017927] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/24/2015] [Indexed: 01/30/2023]
Abstract
Here, an automated procedure is described to identify the positions of many cryocooled crystals mounted on the same sample holder, to rapidly predict and rank their relative diffraction strengths and to collect partial X-ray diffraction data sets from as many of the crystals as desired. Subsequent hierarchical cluster analysis then allows the best combination of partial data sets, optimizing the quality of the final data set obtained. The results of applying the method developed to various systems and scenarios including the compilation of a complete data set from tiny crystals of the membrane protein bacteriorhodopsin and the collection of data sets for successful structure determination using the single-wavelength anomalous dispersion technique are also presented.
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Affiliation(s)
- Ulrich Zander
- Structural Biology Group, European Synchrotron Radiation Facility, CS 40220, 38043 Grenoble, France
| | - Gleb Bourenkov
- European Molecular Biology Laboratory, Hamburg Outstation, Notkestrasse 85, 22607 Hamburg, Germany
| | - Alexander N. Popov
- Structural Biology Group, European Synchrotron Radiation Facility, CS 40220, 38043 Grenoble, France
| | - Daniele de Sanctis
- Structural Biology Group, European Synchrotron Radiation Facility, CS 40220, 38043 Grenoble, France
| | - Olof Svensson
- Structural Biology Group, European Synchrotron Radiation Facility, CS 40220, 38043 Grenoble, France
| | - Andrew A. McCarthy
- European Molecular Biology Laboratory, Grenoble Outstation, 71 Avenue des Martyrs, CS 90181, 38042 Grenoble, France
- Unit of Virus Host-Cell Interactions, Université Grenoble Alpes–EMBL–CNRS, 38042 Grenoble, France
| | - Ekaterina Round
- Université Grenoble Alpes, IBS, 38044 Grenoble, France
- CNRS, IBS, 38044 Grenoble, France
- CEA, IBS, 38044 Grenoble, France
- ICS-6: Molecular Biophysics, Institute of Complex Systems (ICS), Research Centre Juelich, 52425 Juelich, Germany
- Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy 141700, Russian Federation
| | - Valentin Gordeliy
- Université Grenoble Alpes, IBS, 38044 Grenoble, France
- CNRS, IBS, 38044 Grenoble, France
- CEA, IBS, 38044 Grenoble, France
- ICS-6: Molecular Biophysics, Institute of Complex Systems (ICS), Research Centre Juelich, 52425 Juelich, Germany
- Laboratory for Advanced Studies of Membrane Proteins, Moscow Institute of Physics and Technology, Dolgoprudniy 141700, Russian Federation
| | | | - Gordon A. Leonard
- Structural Biology Group, European Synchrotron Radiation Facility, CS 40220, 38043 Grenoble, France
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13
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Liu W, Hanson MA, Stevens RC, Cherezov V. LCP-Tm: an assay to measure and understand stability of membrane proteins in a membrane environment. Biophys J 2010; 98:1539-48. [PMID: 20409473 PMCID: PMC2856142 DOI: 10.1016/j.bpj.2009.12.4296] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 12/03/2009] [Accepted: 12/11/2009] [Indexed: 11/27/2022] Open
Abstract
Structural and functional studies of membrane proteins are limited by their poor stability outside the native membrane environment. The development of novel methods to efficiently stabilize membrane proteins immediately after purification is important for biophysical studies, and is likely to be critical for studying the more challenging human targets. Lipidic cubic phase (LCP) provides a suitable stabilizing matrix for studying membrane proteins by spectroscopic and other biophysical techniques, including obtaining highly ordered membrane protein crystals for structural studies. We have developed a robust and accurate assay, LCP-Tm, for measuring the thermal stability of membrane proteins embedded in an LCP matrix. In its two implementations, protein denaturation is followed either by a change in the intrinsic protein fluorescence on ligand release, or by an increase in the fluorescence of a thiol-binding reporter dye that measures exposure of cysteines buried in the native structure. Application of the LCP-Tm assay to an engineered human beta2-adrenergic receptor and bacteriorhodopsin revealed a number of factors that increased protein stability in LCP. This assay has the potential to guide protein engineering efforts and identify stabilizing conditions that may improve the chances of obtaining high-resolution structures of intrinsically unstable membrane proteins.
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Affiliation(s)
| | | | | | - Vadim Cherezov
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, California
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14
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Shimono K, Goto M, Kikukawa T, Miyauchi S, Shirouzu M, Kamo N, Yokoyama S. Production of functional bacteriorhodopsin by an Escherichia coli cell-free protein synthesis system supplemented with steroid detergent and lipid. Protein Sci 2009; 18:2160-71. [PMID: 19746358 DOI: 10.1002/pro.230] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cell-free expression has become a highly promising tool for the efficient production of membrane proteins. In this study, we used a dialysis-based Escherichia coli cell-free system for the production of a membrane protein actively integrated into liposomes. The membrane protein was the light-driven proton pump bacteriorhodopsin, consisting of seven transmembrane alpha-helices. The cell-free expression system in the dialysis mode was supplemented with a combination of a detergent and a natural lipid, phosphatidylcholine from egg yolk, in only the reaction mixture. By examining a variety of detergents, we found that the combination of a steroid detergent (digitonin, cholate, or CHAPS) and egg phosphatidylcholine yielded a large amount (0.3-0.7 mg/mL reaction mixture) of the fully functional bacteriorhodopsin. We also analyzed the process of functional expression in our system. The synthesized polypeptide was well protected from aggregation by the detergent-lipid mixed micelles and/or lipid disks, and was integrated into liposomes upon detergent removal by dialysis. This approach might be useful for the high yield production of functional membrane proteins.
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Affiliation(s)
- Kazumi Shimono
- RIKEN Systems and Structural Biology Center, Yokohama, Japan
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15
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Efremov R, Gordeliy VI, Heberle J, Büldt G. Time-resolved microspectroscopy on a single crystal of bacteriorhodopsin reveals lattice-induced differences in the photocycle kinetics. Biophys J 2006; 91:1441-51. [PMID: 16731567 PMCID: PMC1518640 DOI: 10.1529/biophysj.106.083345] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The determination of the intermediate state structures of the bacteriorhodopsin photocycle has lead to an unprecedented level of understanding of the catalytic process exerted by a membrane protein. However, the crystallographic structures of the intermediate states are only relevant if the working cycle is not impaired by the crystal lattice. Therefore, we applied visible and Fourier transform infrared spectroscopy (FTIR) microspectroscopy with microsecond time resolution to compare the photoreaction of a single bacteriorhodopsin crystal to that of bacteriorhodopsin residing in the native purple membrane. The analysis of the FTIR difference spectra of the resolved intermediate states reveals great similarity in structural changes taking place in the crystal and in PM. However, the kinetics of the photocycle are significantly altered in the three-dimensional crystal as compared to PM. Strikingly, the L state decay is accelerated in the crystal, whereas the M decay is delayed. The physical origin of this deviation and the implications for trapping of intermediate states are discussed. As a methodological advance, time-resolved step-scan FTIR spectroscopy on a single protein crystal is demonstrated for the first time which may be used in the future to gauge the functionality of other crystallized proteins with the molecular resolution of vibrational spectroscopy.
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Affiliation(s)
- R Efremov
- Forschungszentrum Jülich, IBI-2: Structural Biology, 52425 Jülich, Germany
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16
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Moukhametzianov R, Klare JP, Efremov R, Baeken C, Göppner A, Labahn J, Engelhard M, Büldt G, Gordeliy VI. Development of the signal in sensory rhodopsin and its transfer to the cognate transducer. Nature 2006; 440:115-9. [PMID: 16452929 DOI: 10.1038/nature04520] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2005] [Accepted: 12/15/2005] [Indexed: 11/09/2022]
Abstract
The microbial phototaxis receptor sensory rhodopsin II (NpSRII, also named phoborhodopsin) mediates the photophobic response of the haloarchaeon Natronomonas pharaonis by modulating the swimming behaviour of the bacterium. After excitation by blue-green light NpSRII triggers, by means of a tightly bound transducer protein (NpHtrII), a signal transduction chain homologous with the two-component system of eubacterial chemotaxis. Two molecules of NpSRII and two molecules of NpHtrII form a 2:2 complex in membranes as shown by electron paramagnetic resonance and X-ray structure analysis. Here we present X-ray structures of the photocycle intermediates K and late M (M2) explaining the evolution of the signal in the receptor after retinal isomerization and the transfer of the signal to the transducer in the complex. The formation of late M has been correlated with the formation of the signalling state. The observed structural rearrangements allow us to propose the following mechanism for the light-induced activation of the signalling complex. On excitation by light, retinal isomerization leads in the K state to a rearrangement of a water cluster that partly disconnects two helices of the receptor. In the transition to late M the changes in the hydrogen bond network proceed further. Thus, in late M state an altered tertiary structure establishes the signalling state of the receptor. The transducer responds to the activation of the receptor by a clockwise rotation of about 15 degrees of helix TM2 and a displacement of this helix by 0.9 A at the cytoplasmic surface.
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17
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Efremov R, Moukhametzianov R, Büldt G, Gordeliy V. Physical detwinning of hemihedrally twinned hexagonal crystals of bacteriorhodopsin. Biophys J 2004; 87:3608-13. [PMID: 15339801 PMCID: PMC1304826 DOI: 10.1529/biophysj.104.046573] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hexagonal crystals of the membrane protein bacteriorhodopsin of space group P6 3 grown in lipidic cubic phase are twinned hemihedrally. It was shown that slow changes of salt concentration in the mother liquor lead to a split of crystals so that the split parts preserved high diffraction quality. Analysis of diffraction data from split crystals by Yeates statistic and Britton plot showed that the split parts are free of twinning. It is concluded that crystals of bacteriorhodopsin are composed of several macroscopic twinning domains with sizes comparable to the original crystal. The appearance of twinning domains during crystal growth and the mechanism of splitting are discussed.
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Affiliation(s)
- Rouslan Efremov
- Institute for Structural Biology (IBI-2), Forschungszentrum Jülich, D-52425 Jülich, Germany
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