51
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Gorski C, Riddle R, Toporik H, Da Z, Dobson Z, Williams D, Mazor Y. The structure of the Physcomitrium patens photosystem I reveals a unique Lhca2 paralogue replacing Lhca4. NATURE PLANTS 2022; 8:307-316. [PMID: 35190662 DOI: 10.1038/s41477-022-01099-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 01/11/2022] [Indexed: 05/10/2023]
Abstract
The moss Physcomitrium patens diverged from green algae shortly after the colonization of land by ancient plants. This colonization posed new environmental challenges, which drove evolutionary processes. The photosynthetic machinery of modern flowering plants is adapted to the high light conditions on land. Red-shifted Lhca4 antennae are present in the photosystem I light-harvesting complex of many green-lineage plants but absent in P. patens. The cryo-EM structure of the P. patens photosystem I light-harvesting complex I supercomplex (PSI-LHCI) at 2.8 Å reveals that Lhca4 is replaced by a unique Lhca2 paralogue in moss. This PSI-LHCI supercomplex also retains the PsaM subunit, present in Cyanobacteria and several algal species but lost in vascular plants, and the PsaO subunit responsible for binding light-harvesting complex II. The blue-shifted Lhca2 paralogue and chlorophyll b enrichment relative to flowering plants make the P. patens PSI-LHCI spectroscopically unique among other green-lineage supercomplexes. Overall, the structure represents an evolutionary intermediate PSI with the crescent-shaped LHCI common in vascular plants, and contains a unique Lhca2 paralogue that facilitates the moss's adaptation to low-light niches.
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Affiliation(s)
- C Gorski
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - R Riddle
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - H Toporik
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - Z Da
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - Z Dobson
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA
| | - D Williams
- John M. Cowley Center for High Resolution Electron Microscopy, Arizona State University, Tempe, AZ, USA
| | - Y Mazor
- School of Molecular Sciences, Arizona State University, Tempe, AZ, USA.
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, USA.
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52
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Calcraft T, Rosenthal PB. Cryogenic electron microscopy approaches that combine images and tilt series. Microscopy (Oxf) 2022; 71:i15-i22. [PMID: 35275182 PMCID: PMC8855521 DOI: 10.1093/jmicro/dfab053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/29/2021] [Accepted: 01/28/2022] [Indexed: 11/12/2022] Open
Abstract
Cryogenic electron microscopy can be widely applied to biological specimens from the molecular to the cellular scale. In single-particle analysis, 3D structures may be obtained in high resolution by averaging 2D images of single particles in random orientations. For pleomorphic specimens, structures may be obtained by recording the tilt series of a single example of the specimen and calculating tomograms. Where many copies of a single structure such as a protein or nucleic acid assembly are present within the tomogram, averaging of the sub-volumes (subtomogram averaging) has been successfully applied. The choice of data collection method for any given specimen may depend on the structural question of interest and is determined by the radiation sensitivity of the specimen. Here, we survey some recent developments on the use of hybrid methods for recording and analysing data from radiation-sensitive biological specimens. These include single-particle reconstruction from 2D images where additional views are recorded at a single tilt angle of the specimen and methods where image tilt series, initially used for tomogram reconstruction, are processed as individual single-particle images. There is a continuum of approaches now available to maximize structural information obtained from the specimen.
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Affiliation(s)
- Thomas Calcraft
- Structural Biology of Cells and Viruses Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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53
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Qian P, Gardiner AT, Šímová I, Naydenova K, Croll TI, Jackson PJ, Nupur, Kloz M, Čubáková P, Kuzma M, Zeng Y, Castro-Hartmann P, van Knippenberg B, Goldie KN, Kaftan D, Hrouzek P, Hájek J, Agirre J, Siebert CA, Bína D, Sader K, Stahlberg H, Sobotka R, Russo CJ, Polívka T, Hunter CN, Koblížek M. 2.4-Å structure of the double-ring Gemmatimonas phototrophica photosystem. SCIENCE ADVANCES 2022; 8:eabk3139. [PMID: 35171663 PMCID: PMC8849296 DOI: 10.1126/sciadv.abk3139] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 12/22/2021] [Indexed: 07/21/2023]
Abstract
Phototrophic Gemmatimonadetes evolved the ability to use solar energy following horizontal transfer of photosynthesis-related genes from an ancient phototrophic proteobacterium. The electron cryo-microscopy structure of the Gemmatimonas phototrophica photosystem at 2.4 Å reveals a unique, double-ring complex. Two unique membrane-extrinsic polypeptides, RC-S and RC-U, hold the central type 2 reaction center (RC) within an inner 16-subunit light-harvesting 1 (LH1) ring, which is encircled by an outer 24-subunit antenna ring (LHh) that adds light-gathering capacity. Femtosecond kinetics reveal the flow of energy within the RC-dLH complex, from the outer LHh ring to LH1 and then to the RC. This structural and functional study shows that G. phototrophica has independently evolved its own compact, robust, and highly effective architecture for harvesting and trapping solar energy.
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Affiliation(s)
- Pu Qian
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Alastair T. Gardiner
- Center Algatech, Institute of Microbiology, Czech Academy of Sciences, 37981 Třeboň, Czechia
| | - Ivana Šímová
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czechia
| | - Katerina Naydenova
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Tristan I. Croll
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Philip J. Jackson
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Nupur
- Center Algatech, Institute of Microbiology, Czech Academy of Sciences, 37981 Třeboň, Czechia
| | - Miroslav Kloz
- ELI Beamlines, Institute of Physics of the Czech Academy of Sciences, Na Slovance 1999/2, 182 21 Prague, Czechia
| | - Petra Čubáková
- ELI Beamlines, Institute of Physics of the Czech Academy of Sciences, Na Slovance 1999/2, 182 21 Prague, Czechia
| | - Marek Kuzma
- Lab of Molecular Structure, Institute of Microbiology, Czech Academy of Sciences, Prague, Czechia
| | - Yonghui Zeng
- Department of Plant and Environmental Sciences, University of Copenhagen, Nørregade 10, DK-1165 Copenhagen, Denmark
| | - Pablo Castro-Hartmann
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Bart van Knippenberg
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Kenneth N. Goldie
- BioEM lab, Biozentrum, University of Basel, Mattenstrasse 26, 4058 Basel, Switzerland
| | - David Kaftan
- Center Algatech, Institute of Microbiology, Czech Academy of Sciences, 37981 Třeboň, Czechia
| | - Pavel Hrouzek
- Center Algatech, Institute of Microbiology, Czech Academy of Sciences, 37981 Třeboň, Czechia
| | - Jan Hájek
- Center Algatech, Institute of Microbiology, Czech Academy of Sciences, 37981 Třeboň, Czechia
| | - Jon Agirre
- Department of Chemistry, University of York, York YO10 5DD, UK
| | | | - David Bína
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czechia
| | - Kasim Sader
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Henning Stahlberg
- Laboratory of Biological Electron Microscopy, Institute of Physics, SB, EPFL, and Faculty of Biology and Medicine, Uni Lausanne, CH-1015 Lausanne, Switzerland
| | - Roman Sobotka
- Center Algatech, Institute of Microbiology, Czech Academy of Sciences, 37981 Třeboň, Czechia
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czechia
| | - Christopher J. Russo
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Tomáš Polívka
- Faculty of Science, University of South Bohemia, 37005 České Budějovice, Czechia
| | - C. Neil Hunter
- School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Michal Koblížek
- Center Algatech, Institute of Microbiology, Czech Academy of Sciences, 37981 Třeboň, Czechia
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54
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Chen S, Li J, Vinothkumar KR, Henderson R. Interaction of human erythrocyte catalase with air-water interface in cryoEM. Microscopy (Oxf) 2022; 71:i51-i59. [PMID: 35275189 PMCID: PMC8855524 DOI: 10.1093/jmicro/dfab037] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/13/2021] [Accepted: 09/16/2021] [Indexed: 11/14/2022] Open
Abstract
One of the key goals in single-particle cryo-microscopy is to obtain a uniform distribution of particle orientations, so that the three-dimensional structure has isotropic resolution in Fourier space. A common problem arises from the interaction of protein molecules with the air-water interface that exists on both surfaces of the thin film of liquid that is formed prior to plunge-freezing into liquid ethane. Some proteins and other macromolecular complexes are disrupted by interaction with the air-water interface. Other proteins or macromolecules either become concentrated through their interaction with the interface or are excluded because they bind strongly to some other part of the grid or the filter paper used in blotting. In this paper, the interaction of human erythrocyte catalase with the air-water interface is investigated and minimized by the addition of certain detergents. Detergents can form an amphipathic monolayer at the air-water interface that creates a barrier and leaves the molecules free to adopt a variety of orientations, thus facilitating the 3D structure determination. These results suggest that further characterization and development of detergents for cryo-microscopy plunge-freezing would be useful.
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Affiliation(s)
- Shaoxia Chen
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Jade Li
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Kutti R Vinothkumar
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
- National Centre for Biological Sciences (NCBS), Tata Institute of Fundamental Research, Bellary Road, Bengaluru 560065, India
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55
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Rebelo-Guiomar P, Pellegrino S, Dent KC, Sas-Chen A, Miller-Fleming L, Garone C, Van Haute L, Rogan JF, Dinan A, Firth AE, Andrews B, Whitworth AJ, Schwartz S, Warren AJ, Minczuk M. A late-stage assembly checkpoint of the human mitochondrial ribosome large subunit. Nat Commun 2022; 13:929. [PMID: 35177605 PMCID: PMC8854578 DOI: 10.1038/s41467-022-28503-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 01/20/2022] [Indexed: 12/04/2022] Open
Abstract
Many cellular processes, including ribosome biogenesis, are regulated through post-transcriptional RNA modifications. Here, a genome-wide analysis of the human mitochondrial transcriptome shows that 2’-O-methylation is limited to residues of the mitoribosomal large subunit (mtLSU) 16S mt-rRNA, introduced by MRM1, MRM2 and MRM3, with the modifications installed by the latter two proteins being interdependent. MRM2 controls mitochondrial respiration by regulating mitoribosome biogenesis. In its absence, mtLSU particles (visualized by cryo-EM at the resolution of 2.6 Å) present disordered RNA domains, partial occupancy of bL36m and bound MALSU1:L0R8F8:mtACP anti-association module, allowing five mtLSU biogenesis intermediates with different intersubunit interface configurations to be placed along the assembly pathway. However, mitoribosome biogenesis does not depend on the methyltransferase activity of MRM2. Disruption of the MRM2 Drosophila melanogaster orthologue leads to mitochondria-related developmental arrest. This work identifies a key checkpoint during mtLSU assembly, essential to maintain mitochondrial homeostasis. Rebelo-Guiomar et al. unveil late stage assembly intermediates of the human mitochondrial ribosome by inactivating the methyltransferase MRM2 in cells. Absence of MRM2 impairs organismal homeostasis, while its catalytic activity is dispensable for mitoribosomal biogenesis.
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Affiliation(s)
- Pedro Rebelo-Guiomar
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK
| | - Simone Pellegrino
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust - MRC Stem Cell Institute, Cambridge Biomedical Campus, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, CB2 0AW, UK.,Department of Haematology, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, CB2 0AW, UK
| | - Kyle C Dent
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust - MRC Stem Cell Institute, Cambridge Biomedical Campus, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, CB2 0AW, UK.,Department of Haematology, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, CB2 0AW, UK.,MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Aldema Sas-Chen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 76100, Israel.,Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Leonor Miller-Fleming
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK
| | - Caterina Garone
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Department of Medical and Surgical Sciences, University of Bologna, Bologna, 40137, Italy
| | - Lindsey Van Haute
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK
| | - Jack F Rogan
- STORM Therapeutics Limited, Babraham Research Campus, Moneta Building, Cambridge, CB22 3AT, UK
| | - Adam Dinan
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Andrew E Firth
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Byron Andrews
- STORM Therapeutics Limited, Babraham Research Campus, Moneta Building, Cambridge, CB22 3AT, UK
| | - Alexander J Whitworth
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK
| | - Schraga Schwartz
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Alan J Warren
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.,Wellcome Trust - MRC Stem Cell Institute, Cambridge Biomedical Campus, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, CB2 0AW, UK.,Department of Haematology, School of Clinical Medicine, University of Cambridge, Cambridge Biomedical Campus, Jeffrey Cheah Biomedical Centre, Puddicombe Way, Cambridge, CB2 0AW, UK
| | - Michal Minczuk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Keith Peters Building, Hills Rd, Cambridge, CB2 0XY, UK.
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56
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Fregoso FE, van Eeuwen T, Simanov G, Rebowski G, Boczkowska M, Zimmet A, Gautreau AM, Dominguez R. Molecular mechanism of Arp2/3 complex inhibition by Arpin. Nat Commun 2022; 13:628. [PMID: 35110533 PMCID: PMC8810855 DOI: 10.1038/s41467-022-28112-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 01/09/2022] [Indexed: 11/09/2022] Open
Abstract
Positive feedback loops involving signaling and actin assembly factors mediate the formation and remodeling of branched actin networks in processes ranging from cell and organelle motility to mechanosensation. The Arp2/3 complex inhibitor Arpin controls the directional persistence of cell migration by interrupting a feedback loop involving Rac-WAVE-Arp2/3 complex, but Arpin’s mechanism of inhibition is unknown. Here, we describe the cryo-EM structure of Arpin bound to Arp2/3 complex at 3.24-Å resolution. Unexpectedly, Arpin binds Arp2/3 complex similarly to WASP-family nucleation-promoting factors (NPFs) that activate the complex. However, whereas NPFs bind to two sites on Arp2/3 complex, on Arp2-ArpC1 and Arp3, Arpin only binds to the site on Arp3. Like NPFs, Arpin has a C-helix that binds at the barbed end of Arp3. Mutagenesis studies in vitro and in cells reveal how sequence differences within the C-helix define the molecular basis for inhibition by Arpin vs. activation by NPFs. The Arp2/3 complex inhibitor Arpin controls cell migration by interrupting a feedback loop involving Rac-WAVE-Arp2/3 complex Here, the authors use structural, biochemical, and cellular studies to reveal Arpin’s mechanism of inhibition.
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Affiliation(s)
- Fred E Fregoso
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Trevor van Eeuwen
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.,Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY, 10065, USA
| | - Gleb Simanov
- Laboratoire de Biologie Structurale de la Cellule, CNRS, Institut Polytechnique de Paris, 91128, Palaiseau, France
| | - Grzegorz Rebowski
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Malgorzata Boczkowska
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Austin Zimmet
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alexis M Gautreau
- Laboratoire de Biologie Structurale de la Cellule, CNRS, Institut Polytechnique de Paris, 91128, Palaiseau, France.,Skolkovo Institute of Science and Technology, 121205, Moscow, Russia
| | - Roberto Dominguez
- Department of Physiology and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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57
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Fan H, Wang B, Zhang Y, Zhu Y, Song B, Xu H, Zhai Y, Qiao M, Sun F. A cryo-electron microscopy support film formed by 2D crystals of hydrophobin HFBI. Nat Commun 2021; 12:7257. [PMID: 34907237 PMCID: PMC8671466 DOI: 10.1038/s41467-021-27596-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/30/2021] [Indexed: 01/27/2023] Open
Abstract
Cryo-electron microscopy (cryo-EM) has become a powerful tool to resolve high-resolution structures of biomacromolecules in solution. However, air-water interface induced preferred orientations, dissociation or denaturation of biomacromolecules during cryo-vitrification remains a limiting factor for many specimens. To solve this bottleneck, we developed a cryo-EM support film using 2D crystals of hydrophobin HFBI. The hydrophilic side of the HFBI film adsorbs protein particles via electrostatic interactions and sequesters them from the air-water interface, allowing the formation of sufficiently thin ice for high-quality data collection. The particle orientation distribution can be regulated by adjusting the buffer pH. Using this support, we determined the cryo-EM structures of catalase (2.29 Å) and influenza haemagglutinin trimer (2.56 Å), which exhibited strong preferred orientations using a conventional cryo-vitrification protocol. We further show that the HFBI film is suitable to obtain high-resolution structures of small proteins, including aldolase (150 kDa, 3.28 Å) and haemoglobin (64 kDa, 3.6 Å). Our work suggests that HFBI films may have broad future applications in increasing the success rate and efficiency of cryo-EM.
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Affiliation(s)
- Hongcheng Fan
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bo Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China
| | - Yan Zhang
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Yun Zhu
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Bo Song
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China
| | - Haijin Xu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China
| | - Yujia Zhai
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China
| | - Mingqiang Qiao
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, College of Life Sciences, Nankai University, 300071, Tianjin, China.
- School of Life Science, Shanxi University, Shanxi, China.
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, 100101, Beijing, China.
- Physical Science Laboratory, Huairou National Comprehensive Science Center, No. 5 Yanqi East Second Street, 101400, Beijing, China.
- Bioland Laboratory, 510005, Guangzhou, Guangdong Province, China.
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58
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Solon AL, Tan Z, Schutt KL, Jepsen L, Haynes SE, Nesvizhskii AI, Sept D, Stumpff J, Ohi R, Cianfrocco MA. Kinesin-binding protein remodels the kinesin motor to prevent microtubule binding. SCIENCE ADVANCES 2021; 7:eabj9812. [PMID: 34797717 PMCID: PMC8604404 DOI: 10.1126/sciadv.abj9812] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/29/2021] [Indexed: 05/30/2023]
Abstract
Kinesins are regulated in space and time to ensure activation only in the presence of cargo. Kinesin-binding protein (KIFBP), which is mutated in Goldberg-Shprintzen syndrome, binds to and inhibits the catalytic motor heads of 8 of 45 kinesin superfamily members, but the mechanism remains poorly defined. Here, we used cryo–electron microscopy and cross-linking mass spectrometry to determine high-resolution structures of KIFBP alone and in complex with two mitotic kinesins, revealing structural remodeling of kinesin by KIFBP. We find that KIFBP remodels kinesin motors and blocks microtubule binding (i) via allosteric changes to kinesin and (ii) by sterically blocking access to the microtubule. We identified two regions of KIFBP necessary for kinesin binding and cellular regulation during mitosis. Together, this work further elucidates the molecular mechanism of KIFBP-mediated kinesin inhibition and supports a model in which structural rearrangement of kinesin motor domains by KIFBP abrogates motor protein activity.
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Affiliation(s)
- April L. Solon
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Zhenyu Tan
- Department of Biophysics, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Katherine L. Schutt
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, USA
| | - Lauren Jepsen
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Sarah E. Haynes
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Alexey I. Nesvizhskii
- Department of Pathology, University of Michigan, Ann Arbor, MI, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - David Sept
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Jason Stumpff
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, USA
| | - Ryoma Ohi
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Michael A. Cianfrocco
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
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59
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Pirazzini M, Grinzato A, Corti D, Barbieri S, Leka O, Vallese F, Tonellato M, Silacci-Fregni C, Piccoli L, Kandiah E, Schiavo G, Zanotti G, Lanzavecchia A, Montecucco C. Exceptionally potent human monoclonal antibodies are effective for prophylaxis and treatment of tetanus in mice. J Clin Invest 2021; 131:151676. [PMID: 34618682 DOI: 10.1172/jci151676] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/28/2021] [Indexed: 01/15/2023] Open
Abstract
We used human monoclonal antibodies (humAbs) to study the mechanism of neuron intoxication by tetanus neurotoxin and to evaluate these antibodies as a safe preventive and therapeutic substitute for hyperimmune sera to treat tetanus in mice. By screening memory B cells from immune donors, we selected 2 tetanus neurotoxin-specific mAbs with exceptionally high neutralizing activities and extensively characterized them both structurally and functionally. We found that these antibodies interfered with the binding and translocation of the neurotoxin into neurons by interacting with 2 epitopes, whose identification pinpoints crucial events in the cellular pathogenesis of tetanus. Our observations explain the neutralization ability of these antibodies, which we found to be exceptionally potent in preventing experimental tetanus when injected into mice long before the toxin. Moreover, their Fab derivatives neutralized tetanus neurotoxin in post-exposure experiments, suggesting their potential for therapeutic use via intrathecal injection. As such, we believe these humAbs, as well as their Fab derivatives, meet the requirements to be considered for prophylactic and therapeutic use in human tetanus and are ready for clinical trials.
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Affiliation(s)
- Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | | | | | - Oneda Leka
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Marika Tonellato
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Chiara Silacci-Fregni
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
| | - Luca Piccoli
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland
| | | | - Giampietro Schiavo
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology and.,UK Dementia Research Institute, University College London, London, United Kingdom
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Università della Svizzera Italiana, Bellinzona, Switzerland.,Fondazione Istituto Nazionale Genetica Molecolare, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico di Milano, Milano, Italy
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Padova, Italy.,Institute of Neuroscience, National Research Council, Padova, Italy
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60
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Structural basis of soluble membrane attack complex packaging for clearance. Nat Commun 2021; 12:6086. [PMID: 34667172 PMCID: PMC8526713 DOI: 10.1038/s41467-021-26366-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 10/01/2021] [Indexed: 12/15/2022] Open
Abstract
Unregulated complement activation causes inflammatory and immunological pathologies with consequences for human disease. To prevent bystander damage during an immune response, extracellular chaperones (clusterin and vitronectin) capture and clear soluble precursors to the membrane attack complex (sMAC). However, how these chaperones block further polymerization of MAC and prevent the complex from binding target membranes remains unclear. Here, we address that question by combining cryo electron microscopy (cryoEM) and cross-linking mass spectrometry (XL-MS) to solve the structure of sMAC. Together our data reveal how clusterin recognizes and inhibits polymerizing complement proteins by binding a negatively charged surface of sMAC. Furthermore, we show that the pore-forming C9 protein is trapped in an intermediate conformation whereby only one of its two transmembrane β-hairpins has unfurled. This structure provides molecular details for immune pore formation and helps explain a complement control mechanism that has potential implications for how cell clearance pathways mediate immune homeostasis. To prevent unregulated complement activation, extracellular chaperones capture soluble precursors to the membrane attack complex (sMAC). Here, structural analysis of sMAC reveals how clusterin recognizes heterogeneous sMAC complexes and inhibits polymerization of complement protein C9.
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61
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Han BG, Glaeser RM. Simple assay for adsorption of proteins to the air-water interface. J Struct Biol 2021; 213:107798. [PMID: 34534654 DOI: 10.1016/j.jsb.2021.107798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 09/05/2021] [Accepted: 09/09/2021] [Indexed: 11/27/2022]
Abstract
A rapid assay is described, based upon the Marangoni effect, which detects the formation of a denatured-protein film at the air-water interface (AWI) of aqueous samples. This assay requires no more than a 20 µL aliquot of sample, at a protein concentration of no more than1 mg/ml, and it can be performed with any buffer that is used to prepare grids for electron cryo-microscopy (cryo-EM). In addition, this assay provides an easy way to estimate the rate at which a given protein forms such a film at the AWI. Use of this assay is suggested as a way to pre-screen the effect of various additives and chemical modifications that one might use to optimize the preparation of grids, although the final proof of optimization still requires further screening of grids in the electron microscope. In those cases when the assay establishes that a given protein does form a sacrificial, denatured-protein monolayer, it is suggested that subsequent optimization strategies might focus on discovering how to improve the adsorption of native proteins onto that monolayer, rather than to prevent its formation. A second alternative might be to bind such proteins to the surface of rationally designed affinity grids, in order to prevent their diffusion to, and unwanted interaction with, the AWI.
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Affiliation(s)
- Bong-Gyoon Han
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, United States
| | - Robert M Glaeser
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, United States.
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62
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Li B, Zhu D, Shi H, Zhang X. Effect of charge on protein preferred orientation at the air-water interface in cryo-electron microscopy. J Struct Biol 2021; 213:107783. [PMID: 34454014 DOI: 10.1016/j.jsb.2021.107783] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/21/2021] [Accepted: 08/21/2021] [Indexed: 01/08/2023]
Abstract
The air-water interface (AWI) tends to adsorb proteins and frequently causes preferred orientation problems in cryo-electron microscopy (cryo-EM). Here, we examined cryo-EM data from protein samples frozen with different detergents and found that both anionic and cationic detergents promoted binding of proteins to the AWI. By contrast, some of the nonionic and zwitterionic detergents tended to prevent proteins from attaching to the AWI. The protein orientation distributions with different anionic detergents were similar and resembled that obtained without detergent. By contrast, cationic detergents gave distinct orientation distributions. Our results indicate that proteins adsorb to charged interface and the negative charge of the AWI plays an important role in adsorbing proteins in the conventional cryo-EM sample preparation. According to these findings, a new method was developed by adding anionic detergent at a concentration between 0.002% and 0.005%. Using this method, the protein particles exhibited a more evenly distributed orientations and still adsorbed to the AWI enabling them embedding in a thin layer of ice with high concentration, which will benefit the cryo-EM structural determination.
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Affiliation(s)
- Bufan Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences (CAS), Beijing 100101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Dongjie Zhu
- School of Life Science, University of Science and Technology of China, Hefei, Anhui 230026, PR China
| | - Huigang Shi
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences (CAS), Beijing 100101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences (CAS), Beijing 100101, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
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63
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Wu K, Wu D, Zhu L, Wu Y. Application of Monolayer Graphene and Its Derivative in Cryo-EM Sample Preparation. Int J Mol Sci 2021; 22:8940. [PMID: 34445650 PMCID: PMC8396334 DOI: 10.3390/ijms22168940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 11/16/2022] Open
Abstract
Cryo-electron microscopy (Cryo-EM) has become a routine technology for resolving the structure of biological macromolecules due to the resolution revolution in recent years. The specimens are typically prepared in a very thin layer of vitrified ice suspending in the holes of the perforated amorphous carbon film. However, the samples prepared by directly applying to the conventional support membranes may suffer from partial or complete denaturation caused by sticking to the air-water interface (AWI). With the application in materials, graphene has also been used recently to improve frozen sample preparation instead of a suspended conventional amorphous thin carbon. It has been proven that graphene or graphene oxide and various chemical modifications on its surface can effectively prevent particles from adsorbing to the AWI, which improves the dispersion, adsorbed number, and orientation preference of frozen particles in the ice layer. Their excellent properties and thinner thickness can significantly reduce the background noise, allowing high-resolution three-dimensional reconstructions using a minimum data set.
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Affiliation(s)
- Ke Wu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China; (K.W.); (D.W.)
| | - Di Wu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China; (K.W.); (D.W.)
| | - Li Zhu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou 730000, China; (K.W.); (D.W.)
- Electron Microscopy Centre of Lanzhou University, Lanzhou 730000, China
| | - Yi Wu
- MOE Key Laboratory of Environment and Genes Related to Diseases, School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an 710049, China
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64
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Sorzano COS, Jiménez-Moreno A, Maluenda D, Ramírez-Aportela E, Martínez M, Cuervo A, Melero R, Conesa JJ, Sánchez-García R, Strelak D, Filipovic J, Fernández-Giménez E, de Isidro-Gómez F, Herreros D, Conesa P, Del Caño L, Fonseca Y, de la Morena JJ, Macías JR, Losana P, Marabini R, Carazo JM. Image Processing in Cryo-Electron Microscopy of Single Particles: The Power of Combining Methods. Methods Mol Biol 2021; 2305:257-289. [PMID: 33950394 DOI: 10.1007/978-1-0716-1406-8_13] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cryo-electron microscopy has established as a mature structural biology technique to elucidate the three-dimensional structure of biological macromolecules. The Coulomb potential of the sample is imaged by an electron beam, and fast semi-conductor detectors produce movies of the sample under study. These movies have to be further processed by a whole pipeline of image-processing algorithms that produce the final structure of the macromolecule. In this chapter, we illustrate this whole processing pipeline putting in value the strength of "meta algorithms," which are the combination of several algorithms, each one with different mathematical rationale, in order to distinguish correctly from incorrectly estimated parameters. We show how this strategy leads to superior performance of the whole pipeline as well as more confident assessments about the reconstructed structures. The "meta algorithms" strategy is common to many fields and, in particular, it has provided excellent results in bioinformatics. We illustrate this combination using the workflow engine, Scipion.
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Affiliation(s)
| | | | | | | | | | - Ana Cuervo
- National Centre for Biotechnology (CSIC), Madrid, Spain
| | - Robert Melero
- National Centre for Biotechnology (CSIC), Madrid, Spain
| | | | | | - David Strelak
- National Centre for Biotechnology (CSIC), Madrid, Spain
| | | | | | | | | | - Pablo Conesa
- National Centre for Biotechnology (CSIC), Madrid, Spain
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65
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The six steps of the complete F 1-ATPase rotary catalytic cycle. Nat Commun 2021; 12:4690. [PMID: 34344897 DOI: 10.1038/s41467-021-25029-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 07/19/2021] [Indexed: 11/09/2022] Open
Abstract
F1Fo ATP synthase interchanges phosphate transfer energy and proton motive force via a rotary catalysis mechanism. Isolated F1-ATPase catalytic cores can hydrolyze ATP, passing through six intermediate conformational states to generate rotation of their central γ-subunit. Although previous structural studies have contributed greatly to understanding rotary catalysis in the F1-ATPase, the structure of an important conformational state (the binding-dwell) has remained elusive. Here, we exploit temperature and time-resolved cryo-electron microscopy to determine the structure of the binding- and catalytic-dwell states of Bacillus PS3 F1-ATPase. Each state shows three catalytic β-subunits in different conformations, establishing the complete set of six states taken up during the catalytic cycle and providing molecular details for both the ATP binding and hydrolysis strokes. We also identify a potential phosphate-release tunnel that indicates how ADP and phosphate binding are coordinated during synthesis. Overall these findings provide a structural basis for the entire F1-ATPase catalytic cycle.
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66
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Danev R, Belousoff M, Liang YL, Zhang X, Eisenstein F, Wootten D, Sexton PM. Routine sub-2.5 Å cryo-EM structure determination of GPCRs. Nat Commun 2021; 12:4333. [PMID: 34267200 PMCID: PMC8282782 DOI: 10.1038/s41467-021-24650-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 06/29/2021] [Indexed: 11/24/2022] Open
Abstract
Cryo-electron microscopy (cryo-EM) of small membrane proteins, such as G protein-coupled receptors (GPCRs), remains challenging. Pushing the performance boundaries of the technique requires quantitative knowledge about the contribution of multiple factors. Here, we present an in-depth analysis and optimization of the main experimental parameters in cryo-EM. We combined actual structural studies with methods development to quantify the effects of the Volta phase plate, zero-loss energy filtering, objective lens aperture, defocus magnitude, total exposure, and grid type. By using this information to carefully maximize the experimental performance, it is now possible to routinely determine GPCR structures at resolutions better than 2.5 Å. The improved fidelity of such maps enables the building of better atomic models and will be crucial for the future expansion of cryo-EM into the structure-based drug design domain. The optimization guidelines given here are not limited to GPCRs and can be applied directly to other small proteins.
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Affiliation(s)
- Radostin Danev
- Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
| | - Matthew Belousoff
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Yi-Lynn Liang
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Confo Therapeutics, Ghent (Zwijnaarde), Belgium
| | - Xin Zhang
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | | | - Denise Wootten
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Patrick M Sexton
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
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67
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Faylo JL, van Eeuwen T, Kim HJ, Gorbea Colón JJ, Garcia BA, Murakami K, Christianson DW. Structural insight on assembly-line catalysis in terpene biosynthesis. Nat Commun 2021; 12:3487. [PMID: 34108468 PMCID: PMC8190136 DOI: 10.1038/s41467-021-23589-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 05/05/2021] [Indexed: 12/20/2022] Open
Abstract
Fusicoccadiene synthase from Phomopsis amygdali (PaFS) is a unique bifunctional terpenoid synthase that catalyzes the first two steps in the biosynthesis of the diterpene glycoside Fusicoccin A, a mediator of 14-3-3 protein interactions. The prenyltransferase domain of PaFS generates geranylgeranyl diphosphate, which the cyclase domain then utilizes to generate fusicoccadiene, the tricyclic hydrocarbon skeleton of Fusicoccin A. Here, we use cryo-electron microscopy to show that the structure of full-length PaFS consists of a central octameric core of prenyltransferase domains, with the eight cyclase domains radiating outward via flexible linker segments in variable splayed-out positions. Cryo-electron microscopy and chemical crosslinking experiments additionally show that compact conformations can be achieved in which cyclase domains are more closely associated with the prenyltransferase core. This structural analysis provides a framework for understanding substrate channeling, since most of the geranylgeranyl diphosphate generated by the prenyltransferase domains remains on the enzyme for cyclization to form fusicoccadiene.
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Affiliation(s)
- Jacque L Faylo
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States
| | - Trevor van Eeuwen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Hee Jong Kim
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Jose J Gorbea Colón
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Kenji Murakami
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - David W Christianson
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA, United States.
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68
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Galindo A, Planelles-Herrero VJ, Degliesposti G, Munro S. Cryo-EM structure of metazoan TRAPPIII, the multi-subunit complex that activates the GTPase Rab1. EMBO J 2021; 40:e107608. [PMID: 34018214 PMCID: PMC8204870 DOI: 10.15252/embj.2020107608] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 03/30/2021] [Accepted: 04/11/2021] [Indexed: 12/19/2022] Open
Abstract
The TRAPP complexes are nucleotide exchange factors that play essential roles in membrane traffic and autophagy. TRAPPII activates Rab11, and TRAPPIII activates Rab1, with the two complexes sharing a core of small subunits that affect nucleotide exchange but being distinguished by specific large subunits that are essential for activity in vivo. Crystal structures of core subunits have revealed the mechanism of Rab activation, but how the core and the large subunits assemble to form the complexes is unknown. We report a cryo‐EM structure of the entire Drosophila TRAPPIII complex. The TRAPPIII‐specific subunits TRAPPC8 and TRAPPC11 hold the catalytic core like a pair of tongs, with TRAPPC12 and TRAPPC13 positioned at the joint between them. TRAPPC2 and TRAPPC2L link the core to the two large arms, with the interfaces containing residues affected by disease‐causing mutations. The TRAPPC8 arm is positioned such that it would contact Rab1 that is bound to the core, indicating how the arm could determine the specificity of the complex. A lower resolution structure of TRAPPII shows a similar architecture and suggests that the TRAPP complexes evolved from a single ur‐TRAPP.
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Affiliation(s)
| | | | | | - Sean Munro
- MRC Laboratory of Molecular Biology, Cambridge, UK
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69
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Sharif H, Hollingsworth LR, Griswold AR, Hsiao JC, Wang Q, Bachovchin DA, Wu H. Dipeptidyl peptidase 9 sets a threshold for CARD8 inflammasome formation by sequestering its active C-terminal fragment. Immunity 2021; 54:1392-1404.e10. [PMID: 34019797 DOI: 10.1016/j.immuni.2021.04.024] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 03/15/2021] [Accepted: 04/26/2021] [Indexed: 01/19/2023]
Abstract
CARD8 detects intracellular danger signals and forms a caspase-1 activating inflammasome. Like the related inflammasome sensor NLRP1, CARD8 autoprocesses into noncovalently associated N-terminal (NT) and C-terminal (CT) fragments and binds the cellular dipeptidyl peptidases DPP8 and 9 (DPP8/9). Certain danger-associated signals, including the DPP8/9 inhibitor Val-boroPro (VbP) and HIV protease, induce proteasome-mediated NT degradation and thereby liberate the inflammasome-forming CT. Here, we report cryoelectron microscopy (cryo-EM) structures of CARD8 bound to DPP9, revealing a repressive ternary complex consisting of DPP9, full-length CARD8, and CARD8-CT. Unlike NLRP1-CT, CARD8-CT does not interact with the DPP8/9 active site and is not directly displaced by VbP. However, larger DPP8/9 active-site probes can directly weaken this complex in vitro, and VbP itself nevertheless appears to disrupt this complex, perhaps indirectly, in cells. Thus, DPP8/9 inhibitors can activate the CARD8 inflammasome by promoting CARD8 NT degradation and by weakening ternary complex stability.
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Affiliation(s)
- Humayun Sharif
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - L Robert Hollingsworth
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew R Griswold
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, USA; Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Jeffrey C Hsiao
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Qinghui Wang
- Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Daniel A Bachovchin
- Pharmacology Program, Weill Cornell Graduate School of Medical Sciences, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA; Chemical Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Hao Wu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA.
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70
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Snowden JS, Alzahrani J, Sherry L, Stacey M, Rowlands DJ, Ranson NA, Stonehouse NJ. Structural insight into Pichia pastoris fatty acid synthase. Sci Rep 2021; 11:9773. [PMID: 33963233 PMCID: PMC8105331 DOI: 10.1038/s41598-021-89196-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 04/19/2021] [Indexed: 11/24/2022] Open
Abstract
Type I fatty acid synthases (FASs) are critical metabolic enzymes which are common targets for bioengineering in the production of biofuels and other products. Serendipitously, we identified FAS as a contaminant in a cryoEM dataset of virus-like particles (VLPs) purified from P. pastoris, an important model organism and common expression system used in protein production. From these data, we determined the structure of P. pastoris FAS to 3.1 Å resolution. While the overall organisation of the complex was typical of type I FASs, we identified several differences in both structural and enzymatic domains through comparison with the prototypical yeast FAS from S. cerevisiae. Using focussed classification, we were also able to resolve and model the mobile acyl-carrier protein (ACP) domain, which is key for function. Ultimately, the structure reported here will be a useful resource for further efforts to engineer yeast FAS for synthesis of alternate products.
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Affiliation(s)
- Joseph S Snowden
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Jehad Alzahrani
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Lee Sherry
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Martin Stacey
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - David J Rowlands
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
| | - Nicola J Stonehouse
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK.
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71
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Weissenberger G, Henderikx RJM, Peters PJ. Understanding the invisible hands of sample preparation for cryo-EM. Nat Methods 2021; 18:463-471. [PMID: 33963356 DOI: 10.1038/s41592-021-01130-6] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 03/30/2021] [Indexed: 02/03/2023]
Abstract
Cryo-electron microscopy (cryo-EM) is rapidly becoming an attractive method in the field of structural biology. With the exploding popularity of cryo-EM, sample preparation must evolve to prevent congestion in the workflow. The dire need for improved microscopy samples has led to a diversification of methods. This Review aims to categorize and explain the principles behind various techniques in the preparation of vitrified samples for the electron microscope. Various aspects and challenges in the workflow are discussed, from sample optimization and carriers to deposition and vitrification. Reliable and versatile specimen preparation remains a challenge, and we hope to give guidelines and posit future directions for improvement.
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Affiliation(s)
- Giulia Weissenberger
- CryoSol-World, Maastricht, the Netherlands.,Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands
| | - Rene J M Henderikx
- CryoSol-World, Maastricht, the Netherlands.,Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands
| | - Peter J Peters
- Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, the Netherlands.
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72
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van Eeuwen T, Li T, Kim HJ, Gorbea Colón JJ, Parker MI, Dunbrack RL, Garcia BA, Tsai KL, Murakami K. Structure of TFIIK for phosphorylation of CTD of RNA polymerase II. SCIENCE ADVANCES 2021; 7:eabd4420. [PMID: 33827808 PMCID: PMC8026125 DOI: 10.1126/sciadv.abd4420] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
During transcription initiation, the general transcription factor TFIIH marks RNA polymerase II by phosphorylating Ser5 of the carboxyl-terminal domain (CTD) of Rpb1, which is followed by extensive modifications coupled to transcription elongation, mRNA processing, and histone dynamics. We have determined a 3.5-Å resolution cryo-electron microscopy (cryo-EM) structure of the TFIIH kinase module (TFIIK in yeast), which is composed of Kin28, Ccl1, and Tfb3, yeast homologs of CDK7, cyclin H, and MAT1, respectively. The carboxyl-terminal region of Tfb3 was lying at the edge of catalytic cleft of Kin28, where a conserved Tfb3 helix served to stabilize the activation loop in its active conformation. By combining the structure of TFIIK with the previous cryo-EM structure of the preinitiation complex, we extend the previously proposed model of the CTD path to the active site of TFIIK.
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Affiliation(s)
- Trevor van Eeuwen
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tao Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Hee Jong Kim
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jose J Gorbea Colón
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mitchell I Parker
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
- Molecular and Cell Biology and Genetics Program, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - Roland L Dunbrack
- Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111, USA
| | - Benjamin A Garcia
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Epigenetics Institute, Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kuang-Lei Tsai
- Department of Biochemistry and Molecular Biology, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
| | - Kenji Murakami
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Atherton J, Moores CA. Cryo-EM of kinesin-binding protein: challenges and opportunities from protein-surface interactions. Acta Crystallogr D Struct Biol 2021; 77:411-423. [PMID: 33825702 PMCID: PMC8025885 DOI: 10.1107/s2059798321001935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/17/2021] [Indexed: 11/10/2022] Open
Abstract
Kinesin-binding protein (KBP) is an important selective inhibitor of specific kinesin family members and its genetic disruption causes Goldberg-Shprintzen syndrome. Cryo-electron microscopy (cryo-EM) has recently been used to reveal the structure of KBP alone (72 kDa) and in complex with the motor domain of the mitotic kinesin-12 KIF15 (110 kDa). KBP is an α-solenoid, tetratricopeptide-repeat protein that interacts with the microtubule-binding region of the kinesin motor domain and blocks microtubule attachment. Numerous challenges arose relating to the behavior of KBP and KBP-kinesin complexes during cryo-EM sample preparation. These included the partial denaturation of KBP by air-water interfaces, protein aggregation resulting from carbon interaction and preferential orientation. Sample preparation with a graphene oxide substrate enabled the eventual structure determination. Here, experiences with preparing these samples are detailed, bringing attention to some of the challenges and opportunities that are likely to arise from protein-surface interactions.
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Affiliation(s)
- Joseph Atherton
- Randall Centre for Cell and Molecular Biophysics, King’s College London, London, United Kingdom
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
| | - Carolyn A. Moores
- Institute of Structural and Molecular Biology, Birkbeck, University of London, London, United Kingdom
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DPP9 sequesters the C terminus of NLRP1 to repress inflammasome activation. Nature 2021; 592:778-783. [PMID: 33731932 PMCID: PMC8299537 DOI: 10.1038/s41586-021-03350-4] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 02/09/2021] [Indexed: 01/31/2023]
Abstract
Nucleotide-binding domain and leucine-rich repeat pyrin-domain containing protein 1 (NLRP1) is an inflammasome sensor that mediates the activation of caspase-1 to induce cytokine maturation and pyroptosis1-4. Gain-of-function mutations of NLRP1 cause severe inflammatory diseases of the skin4-6. NLRP1 contains a function-to-find domain that auto-proteolyses into noncovalently associated subdomains7-9, and proteasomal degradation of the repressive N-terminal fragment of NLRP1 releases its inflammatory C-terminal fragment (NLRP1 CT)10,11. Cytosolic dipeptidyl peptidases 8 and 9 (hereafter, DPP8/DPP9) both interact with NLRP1, and small-molecule inhibitors of DPP8/DPP9 activate NLRP1 by mechanisms that are currently unclear10,12-14. Here we report cryo-electron microscopy structures of the human NLRP1-DPP9 complex alone and with Val-boroPro (VbP), an inhibitor of DPP8/DPP9. The structures reveal a ternary complex that comprises DPP9, full-length NLRP1 and the NLRPT CT. The binding of the NLRP1 CT to DPP9 requires full-length NLRP1, which suggests that NLRP1 activation is regulated by the ratio of NLRP1 CT to full-length NLRP1. Activation of the inflammasome by ectopic expression of the NLRP1 CT is consistently rescued by co-expression of autoproteolysis-deficient full-length NLRP1. The N terminus of the NLRP1 CT inserts into the DPP9 active site, and VbP disrupts this interaction. Thus, VbP weakens the NLRP1-DPP9 interaction and accelerates degradation of the N-terminal fragment10 to induce inflammasome activation. Overall, these data demonstrate that DPP9 quenches low levels of NLRP1 CT and thus serves as a checkpoint for activation of the NLRP1 inflammasome.
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75
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Abstract
CryoEM has become the method of choice for determining the structure of large macromolecular complexes in multiple conformations, at resolutions where unambiguous atomic models can be built. Two effects that have limited progress in single-particle cryoEM are (i) beam-induced movement during image acquisition and (ii) protein adsorption and denaturation at the air-water interface during specimen preparation. While beam-induced movement now appears to have been resolved by all-gold specimen support grids with very small holes, surface effects at the air-water interface are a persistent problem. Strategies to overcome these effects include the use of alternative support films and new techniques for specimen deposition. We examine the future potential of recording perfect images of biological samples for routine structure determination at atomic resolution.
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76
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Baldwin PR, Lyumkis D. Tools for visualizing and analyzing Fourier space sampling in Cryo-EM. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 160:53-65. [PMID: 32645314 PMCID: PMC7785567 DOI: 10.1016/j.pbiomolbio.2020.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 06/08/2020] [Accepted: 06/10/2020] [Indexed: 12/15/2022]
Abstract
A complete understanding of how an orientation distribution contributes to a cryo-EM reconstruction remains lacking. It is necessary to begin critically assessing the set of views to gain an understanding of its effect on experimental reconstructions. Toward that end, we recently suggested that the type of orientation distribution may alter resolution measures in a systematic manner. We introduced the sampling compensation factor (SCF), which incorporates how the collection geometry might change the spectral signal-to-noise ratio (SSNR), irrespective of the other experimental aspects. We show here that knowledge of the sampling restricted to spherical surfaces of sufficiently large radii in Fourier space is equivalent to knowledge of the set of projection views. Moreover, the SCF geometrical factor may be calculated from one such surface. To aid cryo-EM practitioners, we developed a graphical user interface (GUI) tool that evaluates experimental orientation distributions. The GUI returns plots of projection directions, sampling constrained to the surface of a sphere, the SCF value, the fraction of the empty region of Fourier space, and a histogram of the sampling values over the points on a sphere. Finally, a fixed tilt angle may be incorporated to determine how tilting the grid during collection may improve the distribution of views and Fourier space sampling. We advocate this simple conception of sampling and the use of such tools as a complement to the distribution of views to capture the different aspects of the effect of projection directions on cryo-EM reconstructions.
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Affiliation(s)
- Philip R Baldwin
- The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Dmitry Lyumkis
- The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA, 92037, USA; Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 N Torrey Pines Road, La Jolla, CA, 92037, USA.
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77
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Valencia-Sánchez MI, De Ioannes P, Wang M, Truong DM, Lee R, Armache JP, Boeke JD, Armache KJ. Regulation of the Dot1 histone H3K79 methyltransferase by histone H4K16 acetylation. Science 2021; 371:371/6527/eabc6663. [PMID: 33479126 DOI: 10.1126/science.abc6663] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 10/27/2020] [Indexed: 12/30/2022]
Abstract
Dot1 (disruptor of telomeric silencing-1), the histone H3 lysine 79 (H3K79) methyltransferase, is conserved throughout evolution, and its deregulation is found in human leukemias. Here, we provide evidence that acetylation of histone H4 allosterically stimulates yeast Dot1 in a manner distinct from but coordinating with histone H2B ubiquitination (H2BUb). We further demonstrate that this stimulatory effect is specific to acetylation of lysine 16 (H4K16ac), a modification central to chromatin structure. We provide a mechanism of this histone cross-talk and show that H4K16ac and H2BUb play crucial roles in H3K79 di- and trimethylation in vitro and in vivo. These data reveal mechanisms that control H3K79 methylation and demonstrate how H4K16ac, H3K79me, and H2BUb function together to regulate gene transcription and gene silencing to ensure optimal maintenance and propagation of an epigenetic state.
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Affiliation(s)
- Marco Igor Valencia-Sánchez
- Skirball Institute of Biomolecular Medicine, Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Pablo De Ioannes
- Skirball Institute of Biomolecular Medicine, Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Miao Wang
- Skirball Institute of Biomolecular Medicine, Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - David M Truong
- Institute for Systems Genetics, Department of Biochemistry and Molecular Pharmacology, New York University Langone Health, New York, NY 10016, USA
| | - Rachel Lee
- Skirball Institute of Biomolecular Medicine, Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Jean-Paul Armache
- Department of Biochemistry and Molecular Biology, The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Jef D Boeke
- Institute for Systems Genetics, Department of Biochemistry and Molecular Pharmacology, New York University Langone Health, New York, NY 10016, USA
| | - Karim-Jean Armache
- Skirball Institute of Biomolecular Medicine, Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA.
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Naydenova K, Muir KW, Wu LF, Zhang Z, Coscia F, Peet MJ, Castro-Hartmann P, Qian P, Sader K, Dent K, Kimanius D, Sutherland JD, Löwe J, Barford D, Russo CJ. Structure of the SARS-CoV-2 RNA-dependent RNA polymerase in the presence of favipiravir-RTP. Proc Natl Acad Sci U S A 2021; 118:e2021946118. [PMID: 33526596 PMCID: PMC7896311 DOI: 10.1073/pnas.2021946118] [Citation(s) in RCA: 121] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The RNA polymerase inhibitor favipiravir is currently in clinical trials as a treatment for infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), despite limited information about the molecular basis for its activity. Here we report the structure of favipiravir ribonucleoside triphosphate (favipiravir-RTP) in complex with the SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) bound to a template:primer RNA duplex, determined by electron cryomicroscopy (cryoEM) to a resolution of 2.5 Å. The structure shows clear evidence for the inhibitor at the catalytic site of the enzyme, and resolves the conformation of key side chains and ions surrounding the binding pocket. Polymerase activity assays indicate that the inhibitor is weakly incorporated into the RNA primer strand, and suppresses RNA replication in the presence of natural nucleotides. The structure reveals an unusual, nonproductive binding mode of favipiravir-RTP at the catalytic site of SARS-CoV-2 RdRp, which explains its low rate of incorporation into the RNA primer strand. Together, these findings inform current and future efforts to develop polymerase inhibitors for SARS coronaviruses.
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Affiliation(s)
- Katerina Naydenova
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Kyle W Muir
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Long-Fei Wu
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Ziguo Zhang
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Francesca Coscia
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Mathew J Peet
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Pablo Castro-Hartmann
- Materials and Structural Analysis, Thermo Fisher Scientific, 5651 GG Eindhoven, The Netherlands
| | - Pu Qian
- Materials and Structural Analysis, Thermo Fisher Scientific, 5651 GG Eindhoven, The Netherlands
| | - Kasim Sader
- Materials and Structural Analysis, Thermo Fisher Scientific, 5651 GG Eindhoven, The Netherlands
| | - Kyle Dent
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Dari Kimanius
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - John D Sutherland
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom;
| | - Jan Löwe
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom;
| | - David Barford
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom;
| | - Christopher J Russo
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom;
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79
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Nguyen NP, Ersoy I, Gotberg J, Bunyak F, White TA. DRPnet: automated particle picking in cryo-electron micrographs using deep regression. BMC Bioinformatics 2021; 22:55. [PMID: 33557750 PMCID: PMC7869254 DOI: 10.1186/s12859-020-03948-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 12/22/2020] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Identification and selection of protein particles in cryo-electron micrographs is an important step in single particle analysis. In this study, we developed a deep learning-based particle picking network to automatically detect particle centers from cryoEM micrographs. This is a challenging task due to the nature of cryoEM data, having low signal-to-noise ratios with variable particle sizes, shapes, distributions, grayscale variations as well as other undesirable artifacts. RESULTS We propose a double convolutional neural network (CNN) cascade for automated detection of particles in cryo-electron micrographs. This approach, entitled Deep Regression Picker Network or "DRPnet", is simple but very effective in recognizing different particle sizes, shapes, distributions and grayscale patterns corresponding to 2D views of 3D particles. Particles are detected by the first network, a fully convolutional regression network (FCRN), which maps the particle image to a continuous distance map that acts like a probability density function of particle centers. Particles identified by FCRN are further refined to reduce false particle detections by the second classification CNN. DRPnet's first CNN pretrained with only a single cryoEM dataset can be used to detect particles from different datasets without retraining. Compared to RELION template-based autopicking, DRPnet results in better particle picking performance with drastically reduced user interactions and processing time. DRPnet also outperforms the state-of-the-art particle picking networks in terms of the supervised detection evaluation metrics recall, precision, and F-measure. To further highlight quality of the picked particle sets, we compute and present additional performance metrics assessing the resulting 3D reconstructions such as number of 2D class averages, efficiency/angular coverage, Rosenthal-Henderson plots and local/global 3D reconstruction resolution. CONCLUSION DRPnet shows greatly improved time-savings to generate an initial particle dataset compared to manual picking, followed by template-based autopicking. Compared to other networks, DRPnet has equivalent or better performance. DRPnet excels on cryoEM datasets that have low contrast or clumped particles. Evaluating other performance metrics, DRPnet is useful for higher resolution 3D reconstructions with decreased particle numbers or unknown symmetry, detecting particles with better angular orientation coverage.
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Affiliation(s)
- Nguyen Phuoc Nguyen
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO USA
| | - Ilker Ersoy
- Institute for Data Science and Informatics, University of Missouri, Columbia, MO USA
| | - Jacob Gotberg
- Research Computing Support Services, University of Missouri, Columbia, MO USA
| | - Filiz Bunyak
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO USA
| | - Tommi A. White
- Department of Biochemistry, University of Missouri, Columbia, MO USA
- Electron Microscopy Core, University of Missouri, Columbia, MO USA
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80
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Glaeser RM. Preparing Better Samples for Cryo-Electron Microscopy: Biochemical Challenges Do Not End with Isolation and Purification. Annu Rev Biochem 2021; 90:451-474. [PMID: 33556280 DOI: 10.1146/annurev-biochem-072020-020231] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The preparation of extremely thin samples, which are required for high-resolution electron microscopy, poses extreme risk of damaging biological macromolecules due to interactions with the air-water interface. Although the rapid increase in the number of published structures initially gave little indication that this was a problem, the search for methods that substantially mitigate this hazard is now intensifying. The two main approaches under investigation are (a) immobilizing particles onto structure-friendly support films and (b) reducing the length of time during which such interactions may occur. While there is little possibility of outrunning diffusion to the interface, intentional passivation of the interface may slow the process of adsorption and denaturation. In addition, growing attention is being given to gaining more effective control of the thickness of the sample prior to vitrification.
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Affiliation(s)
- Robert M Glaeser
- Department of Molecular and Cell Biology and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, USA;
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81
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Gardiner AT, Naydenova K, Castro-Hartmann P, Nguyen-Phan TC, Russo CJ, Sader K, Hunter CN, Cogdell RJ, Qian P. The 2.4 Å cryo-EM structure of a heptameric light-harvesting 2 complex reveals two carotenoid energy transfer pathways. SCIENCE ADVANCES 2021; 7:7/7/eabe4650. [PMID: 33579696 PMCID: PMC7880592 DOI: 10.1126/sciadv.abe4650] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 12/23/2020] [Indexed: 06/12/2023]
Abstract
We report the 2.4 Ångström resolution structure of the light-harvesting 2 (LH2) complex from Marichromatium (Mch.) purpuratum determined by cryogenic electron microscopy. The structure contains a heptameric ring that is unique among all known LH2 structures, explaining the unusual spectroscopic properties of this bacterial antenna complex. We identify two sets of distinct carotenoids in the structure and describe a network of energy transfer pathways from the carotenoids to bacteriochlorophyll a molecules. The geometry imposed by the heptameric ring controls the resonant coupling of the long-wavelength energy absorption band. Together, these details reveal key aspects of the assembly and oligomeric form of purple bacterial LH2 complexes that were previously inaccessible by any technique.
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Affiliation(s)
- Alastair T Gardiner
- Institute of Molecular, Cell and Systems Biology, Glasgow University, Glasgow G12 8QQ, UK
| | - Katerina Naydenova
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Pablo Castro-Hartmann
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - Tu C Nguyen-Phan
- Institute of Molecular, Cell and Systems Biology, Glasgow University, Glasgow G12 8QQ, UK
| | - Christopher J Russo
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Kasim Sader
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands
| | - C Neil Hunter
- Department of Molecular Biology, The University of Sheffield, Sheffield S10 2TN, UK
| | - Richard J Cogdell
- Institute of Molecular, Cell and Systems Biology, Glasgow University, Glasgow G12 8QQ, UK
| | - Pu Qian
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG Eindhoven, Netherlands.
- Department of Molecular Biology, The University of Sheffield, Sheffield S10 2TN, UK
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82
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Sorzano COS, Semchonok D, Lin SC, Lo YC, Vilas JL, Jiménez-Moreno A, Gragera M, Vacca S, Maluenda D, Martínez M, Ramírez-Aportela E, Melero R, Cuervo A, Conesa JJ, Conesa P, Losana P, Caño LD, de la Morena JJ, Fonseca YC, Sánchez-García R, Strelak D, Fernández-Giménez E, de Isidro F, Herreros D, Kastritis PL, Marabini R, Bruce BD, Carazo JM. Algorithmic robustness to preferred orientations in single particle analysis by CryoEM. J Struct Biol 2021; 213:107695. [PMID: 33421545 DOI: 10.1016/j.jsb.2020.107695] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 12/18/2020] [Accepted: 12/24/2020] [Indexed: 01/30/2023]
Abstract
The presence of preferred orientations in single particle analysis (SPA) by cryo-Electron Microscopy (cryoEM) is currently one of the hurdles preventing many structural analyses from yielding high-resolution structures. Although the existence of preferred orientations is mostly related to the grid preparation, in this technical note, we show that some image processing algorithms used for angular assignment and three-dimensional (3D) reconstruction are more robust than others to these detrimental conditions. We exemplify this argument with three different data sets in which the presence of preferred orientations hindered achieving a 3D reconstruction without artifacts or, even worse, a 3D reconstruction could never be achieved.
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Affiliation(s)
- C O S Sorzano
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain.
| | - D Semchonok
- ZIK HALOMEM & Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Biozentrum, Halle (Saale), Germany
| | - S-C Lin
- Genomics Research Center, Academia Sinica, Taipei 11529, Taiwan
| | - Y-C Lo
- Dept. Biotechnology and Bioindustry Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan
| | - J L Vilas
- Dept. of Biomedical Engineering, Yale University, New Haven, United States
| | - A Jiménez-Moreno
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - M Gragera
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - S Vacca
- Dept. of Biochemistry, Univ. Zurich, Winterthurerstr. 190, CH-8057 Zurich, Switzerland
| | - D Maluenda
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - M Martínez
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - E Ramírez-Aportela
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - R Melero
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - A Cuervo
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - J J Conesa
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - P Conesa
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - P Losana
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - L Del Caño
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - J Jiménez de la Morena
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - Y C Fonseca
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - R Sánchez-García
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - D Strelak
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - E Fernández-Giménez
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - F de Isidro
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - D Herreros
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - P L Kastritis
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - R Marabini
- Escuela Politecnica Superior, Universidad Autónoma de Madrid, 28049 Cantoblanco, Madrid, Spain
| | - B D Bruce
- Dept. Biochemistry & Cellular and Molecular Biology, Univ. Tennessee Knoxville, Knoxville, TN 37996, United States
| | - J M Carazo
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Darwin, 3, Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
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Uchański T, Masiulis S, Fischer B, Kalichuk V, López-Sánchez U, Zarkadas E, Weckener M, Sente A, Ward P, Wohlkönig A, Zögg T, Remaut H, Naismith JH, Nury H, Vranken W, Aricescu AR, Pardon E, Steyaert J. Megabodies expand the nanobody toolkit for protein structure determination by single-particle cryo-EM. Nat Methods 2021; 18:60-68. [PMID: 33408403 PMCID: PMC7611088 DOI: 10.1038/s41592-020-01001-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 10/22/2020] [Indexed: 01/28/2023]
Abstract
Nanobodies are popular and versatile tools for structural biology. They have a compact single immunoglobulin domain organization, bind target proteins with high affinities while reducing their conformational heterogeneity and stabilize multi-protein complexes. Here we demonstrate that engineered nanobodies can also help overcome two major obstacles that limit the resolution of single-particle cryo-electron microscopy reconstructions: particle size and preferential orientation at the water-air interfaces. We have developed and characterized constructs, termed megabodies, by grafting nanobodies onto selected protein scaffolds to increase their molecular weight while retaining the full antigen-binding specificity and affinity. We show that the megabody design principles are applicable to different scaffold proteins and recognition domains of compatible geometries and are amenable for efficient selection from yeast display libraries. Moreover, we demonstrate that megabodies can be used to obtain three-dimensional reconstructions for membrane proteins that suffer from severe preferential orientation or are otherwise too small to allow accurate particle alignment.
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Affiliation(s)
- Tomasz Uchański
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Simonas Masiulis
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Baptiste Fischer
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Valentina Kalichuk
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Uriel López-Sánchez
- CNRS, Université Grenoble Alpes, CEA, Institut de Biologie Structurale, Grenoble, France
| | - Eleftherios Zarkadas
- CNRS, Université Grenoble Alpes, CEA, Institut de Biologie Structurale, Grenoble, France
| | - Miriam Weckener
- Rosalind Franklin Institute, Rutherford Appleton Laboratory, Didcot, UK
| | - Andrija Sente
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Philip Ward
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Alexandre Wohlkönig
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Thomas Zögg
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Han Remaut
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - James H Naismith
- Rosalind Franklin Institute, Rutherford Appleton Laboratory, Didcot, UK
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Hugues Nury
- CNRS, Université Grenoble Alpes, CEA, Institut de Biologie Structurale, Grenoble, France
| | - Wim Vranken
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
- Interuniversity Institute of Bioinformatics in Brussels, ULB-VUB, Brussels, Belgium
| | - A Radu Aricescu
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel, VUB, Brussels, Belgium.
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium.
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84
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de Martín Garrido N, Fu W, Ramlaul K, Zhu Z, Miller D, Boehringer D, Aylett CHS. Direct transfer of electron microscopy samples to wetted carbon and graphene films via a support floatation block. J Struct Biol 2020; 213:107677. [PMID: 33307178 PMCID: PMC7998342 DOI: 10.1016/j.jsb.2020.107677] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/20/2020] [Accepted: 12/01/2020] [Indexed: 01/15/2023]
Abstract
Design of a sample-support transfer block for negative stain and cryo-EM. Direct wetted transfer of 10 μL samples to carbon. Direct wetted transfer of 10 μL samples to graphene. Buffer exchange from 10 μL sample volumes in situ within the block.
Support films are commonly used during cryo-EM specimen preparation to both immobilise the sample and minimise the exposure of particles at the air-water interface. Here we report preparation protocols for carbon and graphene supported single particle electron microscopy samples using a novel 3D-printed sample transfer block to facilitate the direct, wetted, movement of both carbon and graphene supports from the substrate on which they were generated to small volumes (10 μL) of sample. These approaches are simple and inexpensive to implement, minimise hydrophobic contamination of the support films, and are widely applicable to single particle studies. Our approach also allows the direct exchange of the sample buffer on the support film in cases in which it is unsuitable for vitrification, e.g. for samples from centrifugal density gradients that help to preserve sample integrity.
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Affiliation(s)
- Natàlia de Martín Garrido
- Section for Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Wencheng Fu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Kailash Ramlaul
- Section for Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Zining Zhu
- Section for Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - David Miller
- Imperial College Advanced Hackspace, Imperial College London, London, United Kingdom
| | | | - Christopher H S Aylett
- Section for Structural and Synthetic Biology, Department of Infectious Disease, Imperial College London, London, United Kingdom.
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85
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Klebl DP, Gravett MSC, Kontziampasis D, Wright DJ, Bon RS, Monteiro DCF, Trebbin M, Sobott F, White HD, Darrow MC, Thompson RF, Muench SP. Need for Speed: Examining Protein Behavior during CryoEM Grid Preparation at Different Timescales. Structure 2020; 28:1238-1248.e4. [PMID: 32814033 PMCID: PMC7652391 DOI: 10.1016/j.str.2020.07.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/15/2020] [Accepted: 07/29/2020] [Indexed: 12/18/2022]
Abstract
A host of new technologies are under development to improve the quality and reproducibility of cryoelectron microscopy (cryoEM) grid preparation. Here we have systematically investigated the preparation of three macromolecular complexes using three different vitrification devices (Vitrobot, chameleon, and a time-resolved cryoEM device) on various timescales, including grids made within 6 ms (the fastest reported to date), to interrogate particle behavior at the air-water interface for different timepoints. Results demonstrate that different macromolecular complexes can respond to the thin-film environment formed during cryoEM sample preparation in highly variable ways, shedding light on why cryoEM sample preparation can be difficult to optimize. We demonstrate that reducing time between sample application and vitrification is just one tool to improve cryoEM grid quality, but that it is unlikely to be a generic "silver bullet" for improving the quality of every cryoEM sample preparation.
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Affiliation(s)
- David P Klebl
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Molly S C Gravett
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Dimitrios Kontziampasis
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; School of Chemical and Process Engineering, Faculty of Engineering and Physical Sciences, University of Leeds, Leeds LS2 9JT, UK; Institute of Business, Industry & Leadership, University of Cumbria, Carlisle CA1 2HH, UK
| | - David J Wright
- School of Medicine, Faculty of Medicine and Health & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | - Robin S Bon
- School of Medicine, Faculty of Medicine and Health & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | | | - Martin Trebbin
- Hauptman-Woodward Medical Research Institute, Buffalo, NY, USA; Department of Chemistry, State University of New York at Buffalo, Buffalo, NY, USA
| | - Frank Sobott
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK; Department of Chemistry, Biomolecular & Analytical Mass Spectrometry Group, University of Antwerp, Antwerp, Belgium
| | - Howard D White
- Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, VA, USA
| | | | - Rebecca F Thompson
- School of Molecular and Cellular Biology, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
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86
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Carrique L, Fan H, Walker AP, Keown JR, Sharps J, Staller E, Barclay WS, Fodor E, Grimes JM. Host ANP32A mediates the assembly of the influenza virus replicase. Nature 2020; 587:638-643. [PMID: 33208942 PMCID: PMC7116770 DOI: 10.1038/s41586-020-2927-z] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 09/01/2020] [Indexed: 12/11/2022]
Abstract
Aquatic birds represent a vast reservoir from which new pandemic influenza A viruses can emerge1. Influenza viruses contain a negative-sense segmented RNA genome that is transcribed and replicated by the viral heterotrimeric RNA polymerase (FluPol) in the context of viral ribonucleoprotein complexes2,3. RNA polymerases of avian influenza A viruses (FluPolA) replicate viral RNA inefficiently in human cells because of species-specific differences in acidic nuclear phosphoprotein 32 (ANP32), a family of essential host proteins for FluPol activity4. Host-adaptive mutations, particularly a glutamic-acid-to-lysine mutation at amino acid residue 627 (E627K) in the 627 domain of the PB2 subunit, enable avian FluPolA to overcome this restriction and efficiently replicate viral RNA in the presence of human ANP32 proteins. However, the molecular mechanisms of genome replication and the interplay with ANP32 proteins remain largely unknown. Here we report cryo-electron microscopy structures of influenza C virus polymerase (FluPolC) in complex with human and chicken ANP32A. In both structures, two FluPolC molecules form an asymmetric dimer bridged by the N-terminal leucine-rich repeat domain of ANP32A. The C-terminal low-complexity acidic region of ANP32A inserts between the two juxtaposed PB2 627 domains of the asymmetric FluPolA dimer, suggesting a mechanism for how the adaptive PB2(E627K) mutation enables the replication of viral RNA in mammalian hosts. We propose that this complex represents a replication platform for the viral RNA genome, in which one of the FluPol molecules acts as a replicase while the other initiates the assembly of the nascent replication product into a viral ribonucleoprotein complex.
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Affiliation(s)
- Loïc Carrique
- Division of Structural Biology, University of Oxford, Oxford, UK
| | - Haitian Fan
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | | | - Jeremy R Keown
- Division of Structural Biology, University of Oxford, Oxford, UK
| | - Jane Sharps
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Ecco Staller
- Section of Molecular Virology, Imperial College London, London, UK
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Wendy S Barclay
- Section of Molecular Virology, Imperial College London, London, UK
| | - Ervin Fodor
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
| | - Jonathan M Grimes
- Division of Structural Biology, University of Oxford, Oxford, UK.
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, UK.
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87
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Righetto RD, Anton L, Adaixo R, Jakob RP, Zivanov J, Mahi MA, Ringler P, Schwede T, Maier T, Stahlberg H. High-resolution cryo-EM structure of urease from the pathogen Yersinia enterocolitica. Nat Commun 2020; 11:5101. [PMID: 33037208 PMCID: PMC7547064 DOI: 10.1038/s41467-020-18870-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/15/2020] [Indexed: 01/09/2023] Open
Abstract
Urease converts urea into ammonia and carbon dioxide and makes urea available as a nitrogen source for all forms of life except animals. In human bacterial pathogens, ureases also aid in the invasion of acidic environments such as the stomach by raising the surrounding pH. Here, we report the structure of urease from the pathogen Yersinia enterocolitica at 2 Å resolution from cryo-electron microscopy. Y. enterocolitica urease is a dodecameric assembly of a trimer of three protein chains, ureA, ureB and ureC. The high data quality enables detailed visualization of the urease bimetal active site and of the impact of radiation damage. The obtained structure is of sufficient quality to support drug development efforts. Urease is a nickel enzyme responsible for catalyzing the conversion of urea into ammonia and carbon dioxide. Here the authors report a high resolution cryo-EM structure of urease from the bacterial pathogen Yersinia enterocolitica, providing a detailed visualization of the urease bimetal active site and a basis for drug development.
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Affiliation(s)
- Ricardo D Righetto
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Leonie Anton
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Ricardo Adaixo
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Roman P Jakob
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Jasenko Zivanov
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Mohamed-Ali Mahi
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Philippe Ringler
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Torsten Schwede
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Timm Maier
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland.
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88
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Naydenova K, Jia P, Russo CJ. Cryo-EM with sub-1 Å specimen movement. Science 2020; 370:223-226. [PMID: 33033219 PMCID: PMC7116250 DOI: 10.1126/science.abb7927] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 07/15/2020] [Indexed: 12/26/2022]
Abstract
Most information loss in cryogenic electron microscopy (cryo-EM) stems from particle movement during imaging, which remains poorly understood. We show that this movement is caused by buckling and subsequent deformation of the suspended ice, with a threshold that depends directly on the shape of the frozen water layer set by the support foil. We describe a specimen support design that eliminates buckling and reduces electron beam-induced particle movement to less than 1 angstrom. The design allows precise foil tracking during imaging with high-speed detectors, thereby lessening demands on cryostage precision and stability. It includes a maximal density of holes, which increases throughput in automated cryo-EM without degrading data quality. Movement-free imaging allows extrapolation to a three-dimensional map of the specimen at zero electron exposure, before the onset of radiation damage.
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Affiliation(s)
| | - Peipei Jia
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, UK
- ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), Institute for Photonics and Advanced Sensing, School of Physical Sciences, University of Adelaide, Adelaide 5005, Australia
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89
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Wu M, Lander GC. Present and Emerging Methodologies in Cryo-EM Single-Particle Analysis. Biophys J 2020; 119:1281-1289. [PMID: 32919493 PMCID: PMC7567993 DOI: 10.1016/j.bpj.2020.08.027] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/22/2020] [Accepted: 08/26/2020] [Indexed: 11/25/2022] Open
Abstract
Over the past decade, technical and methodological improvements in cryogenic electron microscopy (cryo-EM) single-particle analysis have enabled routine high-resolution structural analyses of biological macromolecules, resulting in a flood of new molecular insights into protracted biological questions. However, despite the tremendous progress and success of the field in recent years, opportunities for improvement remain in various aspects of the cryo-EM single-particle analysis workflow (e.g., sample preparation, image acquisition and processing, and structure validation). Here, we review recent advances that have contributed to the principal methods in cryo-EM and identify persisting challenges and bottlenecks that will require further methodological and hardware development.
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Affiliation(s)
- Mengyu Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California
| | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California.
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90
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O'Reilly FJ, Xue L, Graziadei A, Sinn L, Lenz S, Tegunov D, Blötz C, Singh N, Hagen WJH, Cramer P, Stülke J, Mahamid J, Rappsilber J. In-cell architecture of an actively transcribing-translating expressome. Science 2020; 369:554-557. [PMID: 32732422 DOI: 10.1126/science.abb3758] [Citation(s) in RCA: 154] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 06/01/2020] [Indexed: 12/18/2022]
Abstract
Structural biology studies performed inside cells can capture molecular machines in action within their native context. In this work, we developed an integrative in-cell structural approach using the genome-reduced human pathogen Mycoplasma pneumoniae We combined whole-cell cross-linking mass spectrometry, cellular cryo-electron tomography, and integrative modeling to determine an in-cell architecture of a transcribing and translating expressome at subnanometer resolution. The expressome comprises RNA polymerase (RNAP), the ribosome, and the transcription elongation factors NusG and NusA. We pinpointed NusA at the interface between a NusG-bound elongating RNAP and the ribosome and propose that it can mediate transcription-translation coupling. Translation inhibition dissociated the expressome, whereas transcription inhibition stalled and rearranged it. Thus, the active expressome architecture requires both translation and transcription elongation within the cell.
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Affiliation(s)
- Francis J O'Reilly
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Liang Xue
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.,Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, 69120 Heidelberg, Germany
| | - Andrea Graziadei
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Ludwig Sinn
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Swantje Lenz
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Dimitry Tegunov
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Cedric Blötz
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Neil Singh
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Wim J H Hagen
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Jörg Stülke
- Department of General Microbiology, Institute of Microbiology and Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Julia Mahamid
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL), 69117 Heidelberg, Germany.
| | - Juri Rappsilber
- Bioanalytics Unit, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany. .,Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, EH9 3BF, UK
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91
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Vilas JL, Heymann JB, Tagare HD, Ramirez-Aportela E, Carazo JM, Sorzano C. Local resolution estimates of cryoEM reconstructions. Curr Opin Struct Biol 2020; 64:74-78. [PMID: 32645578 DOI: 10.1016/j.sbi.2020.06.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/28/2020] [Accepted: 06/04/2020] [Indexed: 11/16/2022]
Abstract
The field of cryoEM has quickly advanced in last years with the new biochemical, technological, methodological and computational developments. It has allowed significant progresses in Structural Biology, typically reaching quasi-atomic resolutions in the reconstructed maps. However, this rapid advance has also generated new questions relevant to resolution estimates. The global resolution metrics and their criteria have been deeply discussed in the last decade, but despite that, it remains as an important issue in the field. Recently, the introduction of local resolution measurements has changed how cryoEM reconstructions are interpreted, providing information about the existence of heterogeneity, flexibility, and angular assignment errors, and using it as a tool to aid in modeling. In this review we revisit the concept of local resolution and the different algorithms in the current state of the art. However, the concept of local resolution is not uniquely defined, and each implementation measures different features. This may lead to inappropriate interpretation of local resolution maps. Hence, a set of good practices is provided in this review to avoid misleading and over-interpretation of the reconstructions.
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Affiliation(s)
- J L Vilas
- Department of Biomedical Engineering, Yale University, New Haven, United States
| | - J B Heymann
- Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - H D Tagare
- Department of Biomedical Engineering, Yale University, New Haven, United States
| | - E Ramirez-Aportela
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - J M Carazo
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain
| | - Cos Sorzano
- Biocomputing Unit, Centro Nacional de Biotecnologia (CNB-CSIC), Campus Universidad Autonoma, 28049 Cantoblanco, Madrid, Spain; Univ. San Pablo-CEU, Campus Urb. Monteprincipe, 28668 Boadilla del Monte, Madrid, Spain.
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92
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Lee Y, Warne T, Nehmé R, Pandey S, Dwivedi-Agnihotri H, Chaturvedi M, Edwards PC, García-Nafría J, Leslie AGW, Shukla AK, Tate CG. Molecular basis of β-arrestin coupling to formoterol-bound β 1-adrenoceptor. Nature 2020; 583:862-866. [PMID: 32555462 DOI: 10.1038/s41586-020-2419-1] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 04/07/2020] [Indexed: 12/15/2022]
Abstract
The β1-adrenoceptor (β1AR) is a G-protein-coupled receptor (GPCR) that couples1 to the heterotrimeric G protein Gs. G-protein-mediated signalling is terminated by phosphorylation of the C terminus of the receptor by GPCR kinases (GRKs) and by coupling of β-arrestin 1 (βarr1, also known as arrestin 2), which displaces Gs and induces signalling through the MAP kinase pathway2. The ability of synthetic agonists to induce signalling preferentially through either G proteins or arrestins-known as biased agonism3-is important in drug development, because the therapeutic effect may arise from only one signalling cascade, whereas the other pathway may mediate undesirable side effects4. To understand the molecular basis for arrestin coupling, here we determined the cryo-electron microscopy structure of the β1AR-βarr1 complex in lipid nanodiscs bound to the biased agonist formoterol5, and the crystal structure of formoterol-bound β1AR coupled to the G-protein-mimetic nanobody6 Nb80. βarr1 couples to β1AR in a manner distinct to that7 of Gs coupling to β2AR-the finger loop of βarr1 occupies a narrower cleft on the intracellular surface, and is closer to transmembrane helix H7 of the receptor when compared with the C-terminal α5 helix of Gs. The conformation of the finger loop in βarr1 is different from that adopted by the finger loop of visual arrestin when it couples to rhodopsin8. β1AR coupled to βarr1 shows considerable differences in structure compared with β1AR coupled to Nb80, including an inward movement of extracellular loop 3 and the cytoplasmic ends of H5 and H6. We observe weakened interactions between formoterol and two serine residues in H5 at the orthosteric binding site of β1AR, and find that formoterol has a lower affinity for the β1AR-βarr1 complex than for the β1AR-Gs complex. The structural differences between these complexes of β1AR provide a foundation for the design of small molecules that could bias signalling in the β-adrenoceptors.
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Affiliation(s)
- Yang Lee
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Tony Warne
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Rony Nehmé
- MRC Laboratory of Molecular Biology, Cambridge, UK.,Creoptix AG, Wädenswil, Switzerland
| | - Shubhi Pandey
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | | | - Madhu Chaturvedi
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
| | | | - Javier García-Nafría
- Institute for Biocomputation and Physics of Complex Systems (BIFI), University of Zaragoza, BIFI-IQFR (CSIC), Zaragoza, Spain.,Laboratorio de Microscopías Avanzadas, University of Zaragoza, Zaragoza, Spain
| | | | - Arun K Shukla
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, India
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93
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Ravelli RBG, Nijpels FJT, Henderikx RJM, Weissenberger G, Thewessem S, Gijsbers A, Beulen BWAMM, López-Iglesias C, Peters PJ. Cryo-EM structures from sub-nl volumes using pin-printing and jet vitrification. Nat Commun 2020; 11:2563. [PMID: 32444637 PMCID: PMC7244535 DOI: 10.1038/s41467-020-16392-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 04/17/2020] [Indexed: 01/17/2023] Open
Abstract
The increasing demand for cryo-electron microscopy (cryo-EM) reveals drawbacks in current sample preparation protocols, such as sample waste and lack of reproducibility. Here, we present several technical developments that provide efficient sample preparation for cryo-EM studies. Pin printing substantially reduces sample waste by depositing only a sub-nanoliter volume of sample on the carrier surface. Sample evaporation is mitigated by dewpoint control feedback loops. The deposited sample is vitrified by jets of cryogen followed by submersion into a cryogen bath. Because the cryogen jets cool the sample from the center, premounted autogrids can be used and loaded directly into automated cryo-EMs. We integrated these steps into a single device, named VitroJet. The device’s performance was validated by resolving four standard proteins (apoferritin, GroEL, worm hemoglobin, beta-galactosidase) to ~3 Å resolution using a 200-kV electron microscope. The VitroJet offers a promising solution for improved automated sample preparation in cryo-EM studies. There is a need to further improve the automation of cryo-EM sample preparation to make it more easily accessible for non-specialists, reduce sample waste and increase reproducibility. Here, the authors present VitroJet, a single device, where sub-nl volumes of samples are deposited by pin printing thus eliminating the need for sample blotting, which is followed by jet vitrification, and they show that high-resolution structures can be obtained using four standard proteins.
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Affiliation(s)
- Raimond B G Ravelli
- The Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, Netherlands.
| | - Frank J T Nijpels
- The Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, Netherlands.,CryoSol-World, Maastricht, Netherlands
| | - Rene J M Henderikx
- The Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, Netherlands.,CryoSol-World, Maastricht, Netherlands
| | - Giulia Weissenberger
- The Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, Netherlands.,CryoSol-World, Maastricht, Netherlands
| | - Sanne Thewessem
- Instrument Development, Engineering and Evaluation (IDEE), Maastricht University, Maastricht, Netherlands
| | - Abril Gijsbers
- The Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, Netherlands
| | - Bart W A M M Beulen
- CryoSol-World, Maastricht, Netherlands.,Instrument Development, Engineering and Evaluation (IDEE), Maastricht University, Maastricht, Netherlands
| | - Carmen López-Iglesias
- The Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, Netherlands
| | - Peter J Peters
- The Maastricht Multimodal Molecular Imaging Institute (M4i), Division of Nanoscopy, Maastricht University, Maastricht, Netherlands. .,CryoSol-World, Maastricht, Netherlands.
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94
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Hamdi F, Tüting C, Semchonok DA, Visscher KM, Kyrilis FL, Meister A, Skalidis I, Schmidt L, Parthier C, Stubbs MT, Kastritis PL. 2.7 Å cryo-EM structure of vitrified M. musculus H-chain apoferritin from a compact 200 keV cryo-microscope. PLoS One 2020; 15:e0232540. [PMID: 32374767 PMCID: PMC7202636 DOI: 10.1371/journal.pone.0232540] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 04/16/2020] [Indexed: 12/28/2022] Open
Abstract
Here we present the structure of mouse H-chain apoferritin at 2.7 Å (FSC = 0.143) solved by single particle cryogenic electron microscopy (cryo-EM) using a 200 kV device, the Thermo Fisher Glacios®. This is a compact, two-lens illumination system with a constant power objective lens, without any energy filters or aberration correctors, often thought of as a "screening cryo-microscope". Coulomb potential maps reveal clear densities for main chain carbonyl oxygens, residue side chains (including alternative conformations) and bound solvent molecules. We used a quasi-crystallographic reciprocal space approach to fit model coordinates to the experimental cryo-EM map. We argue that the advantages offered by (a) the high electronic and mechanical stability of the microscope, (b) the high emission stability and low beam energy spread of the high brightness Field Emission Gun (X-FEG), (c) direct electron detection technology and (d) particle-based Contrast Transfer Function (CTF) refinement have contributed to achieving high resolution. Overall, we show that basic electron optical settings for automated cryo-electron microscopy imaging can be used to determine structures approaching atomic resolution.
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Affiliation(s)
- Farzad Hamdi
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Christian Tüting
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Dmitry A. Semchonok
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Koen M. Visscher
- AIMMS Division of Molecular Toxicology, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Fotis L. Kyrilis
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Annette Meister
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
- Institute of Biochemistry and Biotechnology, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Ioannis Skalidis
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Lisa Schmidt
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Christoph Parthier
- Institute of Biochemistry and Biotechnology, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Milton T. Stubbs
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
- Institute of Biochemistry and Biotechnology, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
| | - Panagiotis L. Kastritis
- ZIK HALOmem, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
- Institute of Biochemistry and Biotechnology, Charles-Tanford-Proteinzentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
- ZIK HALOmem, Biozentrum, Martin Luther University Halle-Wittenberg, Halle/Saale, Germany
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95
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Structure of severe fever with thrombocytopenia syndrome virus L protein elucidates the mechanisms of viral transcription initiation. Nat Microbiol 2020; 5:864-871. [PMID: 32341479 DOI: 10.1038/s41564-020-0712-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 03/19/2020] [Indexed: 02/07/2023]
Abstract
Segmented negative-sense RNA viruses (sNSRVs) encode a single-polypeptide polymerase (L protein) or a heterotrimeric polymerase complex to cannibalize host messenger RNA cap structures serving as primers of transcription, and catalyse RNA synthesis. Here, we report the full-length structure of the severe fever with thrombocytopaenia syndrome virus (SFTSV) L protein, as determined by cryogenic electron microscopy at 3.4 Å, leading to an atomic model harbouring three functional parts (an endonuclease, an RNA-dependent RNA polymerase and a cap-binding domain) and two structural domains (an arm domain with a blocker motif and a carboxy-terminal lariat domain). The SFTSV L protein has a compact architecture in which its cap-binding pocket is surprisingly occupied by an Arg finger of the blocker motif, and the endonuclease active centre faces back towards the cap-binding pocket, suggesting that domain rearrangements are necessary to acquire the pre-initiation state of the active site. Our results provide insight into the complete architecture of sNSRV-encoded L protein and further the understanding of sNSRV transcription initiation.
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96
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Michael AK, Grand RS, Isbel L, Cavadini S, Kozicka Z, Kempf G, Bunker RD, Schenk AD, Graff-Meyer A, Pathare GR, Weiss J, Matsumoto S, Burger L, Schübeler D, Thomä NH. Mechanisms of OCT4-SOX2 motif readout on nucleosomes. Science 2020; 368:1460-1465. [PMID: 32327602 DOI: 10.1126/science.abb0074] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/16/2020] [Indexed: 12/12/2022]
Abstract
Transcription factors (TFs) regulate gene expression through chromatin where nucleosomes restrict DNA access. To study how TFs bind nucleosome-occupied motifs, we focused on the reprogramming factors OCT4 and SOX2 in mouse embryonic stem cells. We determined TF engagement throughout a nucleosome at base-pair resolution in vitro, enabling structure determination by cryo-electron microscopy at two preferred positions. Depending on motif location, OCT4 and SOX2 differentially distort nucleosomal DNA. At one position, OCT4-SOX2 removes DNA from histone H2A and histone H3; however, at an inverted motif, the TFs only induce local DNA distortions. OCT4 uses one of its two DNA-binding domains to engage DNA in both structures, reading out a partial motif. These findings explain site-specific nucleosome engagement by the pluripotency factors OCT4 and SOX2, and they reveal how TFs distort nucleosomes to access chromatinized motifs.
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Affiliation(s)
- Alicia K Michael
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Ralph S Grand
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Luke Isbel
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Simone Cavadini
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Zuzanna Kozicka
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.,Faculty of Science, University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - Georg Kempf
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Richard D Bunker
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Andreas D Schenk
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Alexandra Graff-Meyer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Ganesh R Pathare
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Joscha Weiss
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Syota Matsumoto
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Lukas Burger
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.,Swiss Institute of Bioinformatics, 4058 Basel, Switzerland
| | - Dirk Schübeler
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland. .,Faculty of Science, University of Basel, Petersplatz 1, 4003 Basel, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
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97
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Cianfrocco MA, Kellogg EH. What Could Go Wrong? A Practical Guide to Single-Particle Cryo-EM: From Biochemistry to Atomic Models. J Chem Inf Model 2020; 60:2458-2469. [PMID: 32078321 DOI: 10.1021/acs.jcim.9b01178] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Cryo-electron microscopy (cryo-EM) has enjoyed explosive recent growth due to revolutionary advances in hardware and software, resulting in a steady stream of long-awaited, high-resolution structures with unprecedented atomic detail. With this comes an increased number of microscopes, cryo-EM facilities, and scientists eager to leverage the ability to determine protein structures without crystallization. However, numerous pitfalls and considerations beset the path toward high-resolution structures and are not necessarily obvious from literature surveys. Here, we detail the most common misconceptions when initiating a cryo-EM project and common technical hurdles, as well as their solutions, and we conclude with a vision for the future of this exciting field.
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Affiliation(s)
- Michael A Cianfrocco
- Life Sciences Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Elizabeth H Kellogg
- Department of Molecular Biology and Genetics,Cornell University, Ithaca, New York 14850, United States
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98
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Alcón P, Shakeel S, Chen ZA, Rappsilber J, Patel KJ, Passmore LA. FANCD2-FANCI is a clamp stabilized on DNA by monoubiquitination of FANCD2 during DNA repair. Nat Struct Mol Biol 2020; 27:240-248. [PMID: 32066963 PMCID: PMC7067600 DOI: 10.1038/s41594-020-0380-1] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 01/14/2020] [Indexed: 01/18/2023]
Abstract
Vertebrate DNA crosslink repair excises toxic replication-blocking DNA crosslinks. Numerous factors involved in crosslink repair have been identified, and mutations in their corresponding genes cause Fanconi anemia (FA). A key step in crosslink repair is monoubiquitination of the FANCD2-FANCI heterodimer, which then recruits nucleases to remove the DNA lesion. Here, we use cryo-EM to determine the structures of recombinant chicken FANCD2 and FANCI complexes. FANCD2-FANCI adopts a closed conformation when the FANCD2 subunit is monoubiquitinated, creating a channel that encloses double-stranded DNA (dsDNA). Ubiquitin is positioned at the interface of FANCD2 and FANCI, where it acts as a covalent molecular pin to trap the complex on DNA. In contrast, isolated FANCD2 is a homodimer that is unable to bind DNA, suggestive of an autoinhibitory mechanism that prevents premature activation. Together, our work suggests that FANCD2-FANCI is a clamp that is locked onto DNA by ubiquitin, with distinct interfaces that may recruit other DNA repair factors.
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Affiliation(s)
- Pablo Alcón
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | - Zhuo A Chen
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
| | - Juri Rappsilber
- Bioanalytics, Institute of Biotechnology, Technische Universität Berlin, Berlin, Germany
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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99
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Wu M, Lander GC, Herzik MA. Sub-2 Angstrom resolution structure determination using single-particle cryo-EM at 200 keV. J Struct Biol X 2020; 4:100020. [PMID: 32647824 PMCID: PMC7337053 DOI: 10.1016/j.yjsbx.2020.100020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/25/2020] [Accepted: 02/27/2020] [Indexed: 11/30/2022] Open
Abstract
Although the advent of direct electron detectors (DEDs) and software developments have enabled the routine use of single-particle cryogenic electron microscopy (cryo-EM) for structure determination of well-behaved specimens to high-resolution, there nonetheless remains a discrepancy between the resolutions attained for biological specimens and the information limits of modern transmission electron microscopes (TEMs). Instruments operating at 300 kV equipped with DEDs are the current paradigm for high-resolution single-particle cryo-EM, while 200 kV TEMs remain comparatively underutilized for purposes beyond sample screening. Here, we expand upon our prior work and demonstrate that one such 200 kV microscope, the Talos Arctica, equipped with a K2 DED is capable of determining structures of macromolecules to as high as ∼1.7 Å resolution. At this resolution, ordered water molecules are readily assigned and holes in aromatic residues can be clearly distinguished in the reconstructions. This work emphasizes the utility of 200 kV electrons for high-resolution single-particle cryo-EM and applications such as structure-based drug design.
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Affiliation(s)
- Mengyu Wu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Gabriel C. Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Mark A. Herzik
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, United States
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100
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Uchański T, Pardon E, Steyaert J. Nanobodies to study protein conformational states. Curr Opin Struct Biol 2020; 60:117-123. [DOI: 10.1016/j.sbi.2020.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 01/07/2023]
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