1
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Abe KM, Li G, He Q, Grant T, Lim CJ. Small LEA proteins mitigate air-water interface damage to fragile cryo-EM samples during plunge freezing. Nat Commun 2024; 15:7705. [PMID: 39231985 PMCID: PMC11375022 DOI: 10.1038/s41467-024-52091-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 08/27/2024] [Indexed: 09/06/2024] Open
Abstract
Air-water interface (AWI) interactions during cryo-electron microscopy (cryo-EM) sample preparation cause significant sample loss, hindering structural biology research. Organisms like nematodes and tardigrades produce Late Embryogenesis Abundant (LEA) proteins to withstand desiccation stress. Here we show that these LEA proteins, when used as additives during plunge freezing, effectively mitigate AWI damage to fragile multi-subunit molecular samples. The resulting high-resolution cryo-EM maps are comparable to or better than those obtained using existing AWI damage mitigation methods. Cryogenic electron tomography reveals that particles are localized at specific interfaces, suggesting LEA proteins form a barrier at the AWI. This interaction may explain the observed sample-dependent preferred orientation of particles. LEA proteins offer a simple, cost-effective, and adaptable approach for cryo-EM structural biologists to overcome AWI-related sample damage, potentially revitalizing challenging projects and advancing the field of structural biology.
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Affiliation(s)
- Kaitlyn M Abe
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Gan Li
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, WI, 53715, USA
| | - Qixiang He
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Timothy Grant
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- John and Jeanne Rowe Center for Research in Virology, Morgridge Institute for Research, Madison, WI, 53715, USA
| | - Ci Ji Lim
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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2
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Seki S, Miyata T, Norioka N, Tanaka H, Kurisu G, Namba K, Fujii R. Structure-based validation of recombinant light-harvesting complex II. PNAS NEXUS 2024; 3:pgae405. [PMID: 39346626 PMCID: PMC11428208 DOI: 10.1093/pnasnexus/pgae405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 09/05/2024] [Indexed: 10/01/2024]
Abstract
Light-harvesting complex II (LHCII) captures sunlight and dissipates excess energy to drive photosynthesis. To elucidate this mechanism, the individual optical properties of pigments in the LHCII protein must be identified. In vitro reconstitution with apoproteins synthesized by Escherichia coli and pigment-lipid mixtures from natural sources is an effective approach; however, the local environment surrounding each pigment within reconstituted LHCII (rLHCII) has only been indirectly estimated using spectroscopic and biochemical methods. Here, we used cryo-electron microscopy to determine the 3D structure of the rLHCII trimer and found that rLHCII exhibited a structure that was virtually identical to that of native LHCII, with a few exceptions: some C-terminal amino acids were not visible, likely due to aggregation of the His-tags; a carotenoid at the V1 site was not visible; and at site 614 showed mixed occupancy by both chlorophyll a and b molecules. Our observations confirmed the applicability of the in vitro reconstitution technique.
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Affiliation(s)
- Soichiro Seki
- Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Tomoko Miyata
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
- JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Naoko Norioka
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Hideaki Tanaka
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
| | - Genji Kurisu
- Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan
- JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
- Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
- JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Ritsuko Fujii
- Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
- Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
- Research Center for Artificial Photosynthesis, Osaka Metropolitan University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
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3
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Zheng L, Xu J, Wang W, Gao X, Zhao C, Guo W, Sun L, Cheng H, Meng F, Chen B, Sun W, Jia X, Zhou X, Wu K, Liu Z, Ding F, Liu N, Wang HW, Peng H. Self-assembled superstructure alleviates air-water interface effect in cryo-EM. Nat Commun 2024; 15:7300. [PMID: 39181869 PMCID: PMC11344764 DOI: 10.1038/s41467-024-51696-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 08/15/2024] [Indexed: 08/27/2024] Open
Abstract
Cryo-electron microscopy (cryo-EM) has been widely used to reveal the structures of proteins at atomic resolution. One key challenge is that almost all proteins are predominantly adsorbed to the air-water interface during standard cryo-EM specimen preparation. The interaction of proteins with air-water interface will significantly impede the success of reconstruction and achievable resolution. Here, we highlight the critical role of impenetrable surfactant monolayers in passivating the air-water interface problems, and develop a robust effective method for high-resolution cryo-EM analysis, by using the superstructure GSAMs which comprises surfactant self-assembled monolayers (SAMs) and graphene membrane. The GSAMs works well in enriching the orientations and improving particle utilization ratio of multiple proteins, facilitating the 3.3-Å resolution reconstruction of a 100-kDa protein complex (ACE2-RBD), which shows strong preferential orientation using traditional specimen preparation protocol. Additionally, we demonstrate that GSAMs enables the successful determinations of small proteins (<100 kDa) at near-atomic resolution. This study expands the understanding of SAMs and provides a key to better control the interaction of protein with air-water interface.
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Affiliation(s)
- Liming Zheng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Jie Xu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Weihua Wang
- China Academy of Aerospace Science and Innovation, Beijing, 100088, China
| | - Xiaoyin Gao
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Chao Zhao
- Faculty of Materials Science and Energy Engineering, Shenzhen University of Advanced Technology, Shenzhen, 518055, China.
- Shenzhen Institute of Advanced Electronic Materials, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518103, China.
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Weijun Guo
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Luzhao Sun
- Beijing Graphene Institute (BGI), Beijing, 100095, China
| | - Hang Cheng
- Shuimu BioSciences Ltd, Beijing, 100089, China
| | - Fanhao Meng
- Shuimu BioSciences Ltd, Beijing, 100089, China
| | - Buhang Chen
- Beijing Graphene Institute (BGI), Beijing, 100095, China
| | - Weiyu Sun
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Xia Jia
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xiong Zhou
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Kai Wu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Zhongfan Liu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
- Beijing Graphene Institute (BGI), Beijing, 100095, China
| | - Feng Ding
- Faculty of Materials Science and Energy Engineering, Shenzhen University of Advanced Technology, Shenzhen, 518055, China
- Shenzhen Institute of Advanced Electronic Materials, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518103, China
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Nan Liu
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- School of Biological Sciences, The University of Hong Kong, Hong Kong, 999077, China.
| | - Hong-Wei Wang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structures, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Hailin Peng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
- Beijing Graphene Institute (BGI), Beijing, 100095, China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
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4
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Aher A, Urnavicius L, Xue A, Neselu K, Kapoor TM. Structure of the γ-tubulin ring complex-capped microtubule. Nat Struct Mol Biol 2024; 31:1124-1133. [PMID: 38609661 PMCID: PMC11257807 DOI: 10.1038/s41594-024-01264-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 03/04/2024] [Indexed: 04/14/2024]
Abstract
Microtubules are composed of α-tubulin and β-tubulin dimers positioned head-to-tail to form protofilaments that associate laterally in varying numbers. It is not known how cellular microtubules assemble with the canonical 13-protofilament architecture, resulting in micrometer-scale α/β-tubulin tracks for intracellular transport that align with, rather than spiral along, the long axis of the filament. We report that the human ~2.3 MDa γ-tubulin ring complex (γ-TuRC), an essential regulator of microtubule formation that contains 14 γ-tubulins, selectively nucleates 13-protofilament microtubules. Cryogenic electron microscopy reconstructions of γ-TuRC-capped microtubule minus ends reveal the extensive intra-domain and inter-domain motions of γ-TuRC subunits that accommodate luminal bridge components and establish lateral and longitudinal interactions between γ-tubulins and α-tubulins. Our structures suggest that γ-TuRC, an inefficient nucleation template owing to its splayed conformation, can transform into a compacted cap at the microtubule minus end and set the lattice architecture of cellular microtubules.
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Affiliation(s)
- Amol Aher
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, USA
| | - Linas Urnavicius
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, USA
| | - Allen Xue
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, USA
| | - Kasahun Neselu
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY, USA
| | - Tarun M Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, New York, NY, USA.
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5
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Eren E, Watts NR, Conway JF, Wingfield PT. Myxococcus xanthus encapsulin cargo protein EncD is a flavin-binding protein with ferric reductase activity. Proc Natl Acad Sci U S A 2024; 121:e2400426121. [PMID: 38748579 PMCID: PMC11126975 DOI: 10.1073/pnas.2400426121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/18/2024] [Indexed: 05/27/2024] Open
Abstract
Encapsulins are protein nanocompartments that regulate cellular metabolism in several bacteria and archaea. Myxococcus xanthus encapsulins protect the bacterial cells against oxidative stress by sequestering cytosolic iron. These encapsulins are formed by the shell protein EncA and three cargo proteins: EncB, EncC, and EncD. EncB and EncC form rotationally symmetric decamers with ferroxidase centers (FOCs) that oxidize Fe+2 to Fe+3 for iron storage in mineral form. However, the structure and function of the third cargo protein, EncD, have yet to be determined. Here, we report the x-ray crystal structure of EncD in complex with flavin mononucleotide. EncD forms an α-helical hairpin arranged as an antiparallel dimer, but unlike other flavin-binding proteins, it has no β-sheet, showing that EncD and its homologs represent a unique class of bacterial flavin-binding proteins. The cryo-EM structure of EncA-EncD encapsulins confirms that EncD binds to the interior of the EncA shell via its C-terminal targeting peptide. With only 100 amino acids, the EncD α-helical dimer forms the smallest flavin-binding domain observed to date. Unlike EncB and EncC, EncD lacks a FOC, and our biochemical results show that EncD instead is a NAD(P)H-dependent ferric reductase, indicating that the M. xanthus encapsulins act as an integrated system for iron homeostasis. Overall, this work contributes to our understanding of bacterial metabolism and could lead to the development of technologies for iron biomineralization and the production of iron-containing materials for the treatment of various diseases associated with oxidative stress.
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Affiliation(s)
- Elif Eren
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, MD20892
| | - Norman R. Watts
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, MD20892
| | - James F. Conway
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA15260
| | - Paul T. Wingfield
- Protein Expression Laboratory, National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, MD20892
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6
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Watanabe S, Kise Y, Yonezawa K, Inoue M, Shimizu N, Nureki O, Inaba K. Structure of full-length ERGIC-53 in complex with MCFD2 for cargo transport. Nat Commun 2024; 15:2404. [PMID: 38493152 PMCID: PMC10944485 DOI: 10.1038/s41467-024-46747-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 03/07/2024] [Indexed: 03/18/2024] Open
Abstract
ERGIC-53 transports certain subsets of newly synthesized secretory proteins and membrane proteins from the endoplasmic reticulum to the Golgi apparatus. Despite numerous structural and functional studies since its identification, the overall architecture and mechanism of action of ERGIC-53 remain unclear. Here we present cryo-EM structures of full-length ERGIC-53 in complex with its functional partner MCFD2. These structures reveal that ERGIC-53 exists as a homotetramer, not a homohexamer as previously suggested, and comprises a four-leaf clover-like head and a long stalk composed of three sets of four-helix coiled-coil followed by a transmembrane domain. 3D variability analysis visualizes the flexible motion of the long stalk and local plasticity of the head region. Notably, MCFD2 is shown to possess a Zn2+-binding site in its N-terminal lid, which appears to modulate cargo binding. Altogether, distinct mechanisms of cargo capture and release by ERGIC- 53 via the stalk bending and metal binding are proposed.
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Affiliation(s)
- Satoshi Watanabe
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, 980-8577, Japan.
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, 980-8577, Japan.
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, 980-8578, Japan.
| | - Yoshiaki Kise
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kento Yonezawa
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801, Japan
- Center for Digital Green-innovation, Nara Institute of Science and Technology, Ikoma, Nara, 630-0192, Japan
| | - Mariko Inoue
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, 980-8577, Japan
| | - Nobutaka Shimizu
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, 305-0801, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi, 980-8577, Japan.
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, 980-8577, Japan.
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi, 980-8578, Japan.
- Medical Institute of Bioregulation, Kyushu University, Fukuoka, 812-8582, Japan.
- Core Research for Evolutional Science and Technology (CREST), Japan Agency for Medical Research and Development (AMED), Tokyo, Japan.
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7
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Abe KM, Lim CJ. Small LEA proteins as an effective air-water interface protectant for fragile samples during cryo-EM grid plunge freezing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579238. [PMID: 38370693 PMCID: PMC10871254 DOI: 10.1101/2024.02.06.579238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Sample loss due to air-water interface (AWI) interactions is a significant challenge during cryo-electron microscopy (cryo-EM) sample grid plunge freezing. We report that small Late Embryogenesis Abundant (LEA) proteins, which naturally bind to AWI, can protect samples from AWI damage during plunge freezing. This protection is demonstrated with two LEA proteins from nematodes and tardigrades, which rescued the cryo-EM structural determination outcome of two fragile multisubunit protein complexes.
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Affiliation(s)
- Kaitlyn M. Abe
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
| | - Ci Ji Lim
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706
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8
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Aiyer S, Baldwin PR, Tan SM, Shan Z, Oh J, Mehrani A, Bowman ME, Louie G, Passos DO, Đorđević-Marquardt S, Mietzsch M, Hull JA, Hoshika S, Barad BA, Grotjahn DA, McKenna R, Agbandje-McKenna M, Benner SA, Noel JAP, Wang D, Tan YZ, Lyumkis D. Overcoming resolution attenuation during tilted cryo-EM data collection. Nat Commun 2024; 15:389. [PMID: 38195598 PMCID: PMC10776679 DOI: 10.1038/s41467-023-44555-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 12/15/2023] [Indexed: 01/11/2024] Open
Abstract
Structural biology efforts using cryogenic electron microscopy are frequently stifled by specimens adopting "preferred orientations" on grids, leading to anisotropic map resolution and impeding structure determination. Tilting the specimen stage during data collection is a generalizable solution but has historically led to substantial resolution attenuation. Here, we develop updated data collection and image processing workflows and demonstrate, using multiple specimens, that resolution attenuation is negligible or significantly reduced across tilt angles. Reconstructions with and without the stage tilted as high as 60° are virtually indistinguishable. These strategies allowed the reconstruction to 3 Å resolution of a bacterial RNA polymerase with preferred orientation, containing an unnatural nucleotide for studying novel base pair recognition. Furthermore, we present a quantitative framework that allows cryo-EM practitioners to define an optimal tilt angle during data acquisition. These results reinforce the utility of employing stage tilt for data collection and provide quantitative metrics to obtain isotropic maps.
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Affiliation(s)
- Sriram Aiyer
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Philip R Baldwin
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Shi Min Tan
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore
| | - Zelin Shan
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Juntaek Oh
- Division of Pharmaceutical Sciences, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- College of Pharmacy, Kyung Hee University, Seoul, 02247, Republic of Korea
| | - Atousa Mehrani
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Marianne E Bowman
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Gordon Louie
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Dario Oliveira Passos
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | | | - Mario Mietzsch
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Joshua A Hull
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Shuichi Hoshika
- Foundation for Applied Molecular Evolution, 13709 Progress Blvd Box 7, Alachua, FL, 32615, USA
| | - Benjamin A Barad
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Danielle A Grotjahn
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Robert McKenna
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Mavis Agbandje-McKenna
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Steven A Benner
- Foundation for Applied Molecular Evolution, 13709 Progress Blvd Box 7, Alachua, FL, 32615, USA
| | - Joseph A P Noel
- Jack H. Skirball Center for Chemical Biology and Proteomics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Dong Wang
- Division of Pharmaceutical Sciences, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, 92093, USA
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Yong Zi Tan
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore, 117558, Singapore.
- Disease Intervention Technology Laboratory (DITL), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Singapore, 138648, Singapore.
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore, 138673, Republic of Singapore.
| | - Dmitry Lyumkis
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA.
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA.
- Graduate School of Biological Sciences, Section of Molecular Biology, University of California San Diego, La Jolla, CA, 92093, USA.
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9
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Lee J, Zepeda SK, Park YJ, Taylor AL, Quispe J, Stewart C, Leaf EM, Treichel C, Corti D, King NP, Starr TN, Veesler D. Broad receptor tropism and immunogenicity of a clade 3 sarbecovirus. Cell Host Microbe 2023; 31:1961-1973.e11. [PMID: 37989312 PMCID: PMC10913562 DOI: 10.1016/j.chom.2023.10.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/12/2023] [Accepted: 10/24/2023] [Indexed: 11/23/2023]
Abstract
Although Rhinolophus bats harbor diverse clade 3 sarbecoviruses, the structural determinants of receptor tropism along with the antigenicity of their spike (S) glycoproteins remain uncharacterized. Here, we show that the African Rhinolophus bat clade 3 sarbecovirus PRD-0038 S has a broad angiotensin-converting enzyme 2 (ACE2) usage and that receptor-binding domain (RBD) mutations further expand receptor promiscuity and enable human ACE2 utilization. We determine a cryo-EM structure of the PRD-0038 RBD bound to Rhinolophus alcyone ACE2, explaining receptor tropism and highlighting differences with SARS-CoV-1 and SARS-CoV-2. Characterization of PRD-0038 S using cryo-EM and monoclonal antibody reactivity reveals its distinct antigenicity relative to SARS-CoV-2 and identifies PRD-0038 cross-neutralizing antibodies for pandemic preparedness. PRD-0038 S vaccination elicits greater titers of antibodies cross-reacting with vaccine-mismatched clade 2 and clade 1a sarbecoviruses compared with SARS-CoV-2 S due to broader antigenic targeting, motivating the inclusion of clade 3 antigens in next-generation vaccines for enhanced resilience to viral evolution.
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Affiliation(s)
- Jimin Lee
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Samantha K Zepeda
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Young-Jun Park
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA
| | - Ashley L Taylor
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Joel Quispe
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Cameron Stewart
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Elizabeth M Leaf
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Catherine Treichel
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Davide Corti
- Humabs Biomed SA, a Subsidiary of Vir. Biotechnology, 6500 Bellinzona, Switzerland
| | - Neil P King
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Tyler N Starr
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Howard Hughes Medical Institute, Seattle, WA 98195, USA.
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10
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Aher A, Urnavicius L, Xue A, Neselu K, Kapoor TM. Structure of the γ-tubulin ring complex-capped microtubule. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.20.567916. [PMID: 38045257 PMCID: PMC10690160 DOI: 10.1101/2023.11.20.567916] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Microtubules are composed of α/β-tubulin dimers positioned head-to-tail to form protofilaments that associate laterally in varying numbers. It is not known how cellular microtubules assemble with the canonical 13-protofilament architecture, resulting in micrometer-scale α/β-tubulin tracks for intracellular transport that align with, rather than spiral along, the filament's long-axis. We report that the human ∼2.3MDa γ-tubulin ring complex (γ-TuRC), an essential regulator of microtubule formation that contains 14 γ-tubulins, selectively nucleates 13-protofilament microtubules. Cryo-EM reconstructions of γ-TuRC-capped microtubule minus-ends reveal the extensive intra- and inter-domain motions of γ-TuRC subunits that accommodate its actin-containing luminal bridge and establish lateral and longitudinal interactions between γ- and α-tubulins. Our structures reveal how free γ-TuRC, an inefficient nucleation template due to its splayed conformation, transforms into a stable cap that blocks addition or loss of α/β-tubulins from minus-ends and sets the lattice architecture of cellular microtubules. One Sentence Summary Structural insights into how the γ-tubulin ring complex nucleates and caps a 13-protofilament microtubule.
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11
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Lee J, Zepeda SK, Park YJ, Taylor AL, Quispe J, Stewart C, Leaf EM, Treichel C, Corti D, King NP, Starr TN, Veesler D. Broad receptor tropism and immunogenicity of a clade 3 sarbecovirus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.12.557371. [PMID: 37745523 PMCID: PMC10515872 DOI: 10.1101/2023.09.12.557371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Although Rhinolophus bats harbor diverse clade 3 sarbecoviruses, the structural determinants of receptor tropism along with the antigenicity of their spike (S) glycoproteins remain uncharacterized. Here, we show that the African Rinolophus bat clade 3 sarbecovirus PRD-0038 S has a broad ACE2 usage and that RBD mutations further expand receptor promiscuity and enable human ACE2 utilization. We determined a cryoEM structure of the PRD-0038 RBD bound to R. alcyone ACE2, explaining receptor tropism and highlighting differences with SARS-CoV-1 and SARS-CoV-2. Characterization of PRD-0038 S using cryoEM and monoclonal antibody reactivity revealed its distinct antigenicity relative to SARS-CoV-2 and identified PRD-0038 cross-neutralizing antibodies for pandemic preparedness. PRD-0038 S vaccination elicited greater titers of antibodies cross-reacting with vaccine-mismatched clade 2 and clade 1a sarbecoviruses compared to SARS-CoV-2 S due to broader antigenic targeting, motivating the inclusion of clade 3 antigens in next-generation vaccines for enhanced resilience to viral evolution.
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Affiliation(s)
- Jimin Lee
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
| | - Samantha K. Zepeda
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
| | - Young-Jun Park
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
- Howard Hughes Medical Institute, Seattle, WA 98195, USA
| | - Ashley L. Taylor
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Joel Quispe
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
| | - Cameron Stewart
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
| | - Elizabeth M. Leaf
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Catherine Treichel
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Davide Corti
- Humabs Biomed SA, a subsidiary of Vir Biotechnology, 6500 Bellinzona, Switzerland
| | - Neil P. King
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
- Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Tyler N. Starr
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, Washington, USA
- Howard Hughes Medical Institute, Seattle, WA 98195, USA
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12
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Chang SYS, Dijkman PM, Wiessing SA, Kudryashev M. Determining the structure of the bacterial voltage-gated sodium channel NaChBac embedded in liposomes by cryo electron tomography and subtomogram averaging. Sci Rep 2023; 13:11523. [PMID: 37460541 PMCID: PMC10352297 DOI: 10.1038/s41598-023-38027-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 06/30/2023] [Indexed: 07/20/2023] Open
Abstract
Voltage-gated sodium channels shape action potentials that propagate signals along cells. When the membrane potential reaches a certain threshold, the channels open and allow sodium ions to flow through the membrane depolarizing it, followed by the deactivation of the channels. Opening and closing of the channels is important for cellular signalling and regulates various physiological processes in muscles, heart and brain. Mechanistic insights into the voltage-gated channels are difficult to achieve as the proteins are typically extracted from membranes for structural analysis which results in the loss of the transmembrane potential that regulates their activity. Here, we report the structural analysis of a bacterial voltage-gated sodium channel, NaChBac, reconstituted in liposomes under an electrochemical gradient by cryo electron tomography and subtomogram averaging. We show that the small channel, most of the residues of which are embedded in the membrane, can be localized using a genetically fused GFP. GFP can aid the initial alignment to an average resulting in a correct structure, but does not help for the final refinement. At a moderate resolution of ˜16 Å the structure of NaChBac in an unrestricted membrane bilayer is 10% wider than the structure of the purified protein previously solved in nanodiscs, suggesting the potential movement of the peripheral voltage-sensing domains. Our study explores the limits of structural analysis of membrane proteins in membranes.
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Affiliation(s)
- Shih-Ying Scott Chang
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), In Situ Structural Biology, Berlin, Germany
- Max Planck Institute of Biophysics, Frankfurt on Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University of Frankfurt on Main, Frankfurt on Main, Germany
| | - Patricia M Dijkman
- Max Planck Institute of Biophysics, Frankfurt on Main, Germany
- Buchmann Institute for Molecular Life Sciences, Goethe University of Frankfurt on Main, Frankfurt on Main, Germany
| | | | - Misha Kudryashev
- Max-Delbrück-Center for Molecular Medicine in the Helmholtz Association (MDC), In Situ Structural Biology, Berlin, Germany.
- Max Planck Institute of Biophysics, Frankfurt on Main, Germany.
- Buchmann Institute for Molecular Life Sciences, Goethe University of Frankfurt on Main, Frankfurt on Main, Germany.
- Institute of Medical Physics and Biophysics, Charité-Universitätsmedizin Berlin, Berlin, Germany.
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13
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Aiyer S, Baldwin PR, Tan SM, Shan Z, Oh J, Mehrani A, Bowman ME, Louie G, Passos DO, Đorđević-Marquardt S, Mietzsch M, Hull JA, Hoshika S, Barad BA, Grotjahn DA, McKenna R, Agbandje-McKenna M, Benner SA, Noel JAP, Wang D, Tan YZ, Lyumkis D. Overcoming Resolution Attenuation During Tilted Cryo-EM Data Collection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.14.548955. [PMID: 37503021 PMCID: PMC10369999 DOI: 10.1101/2023.07.14.548955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Structural biology efforts using cryogenic electron microscopy are frequently stifled by specimens adopting "preferred orientations" on grids, leading to anisotropic map resolution and impeding structure determination. Tilting the specimen stage during data collection is a generalizable solution but has historically led to substantial resolution attenuation. Here, we develop updated data collection and image processing workflows and demonstrate, using multiple specimens, that resolution attenuation is negligible or significantly reduced across tilt angles. Reconstructions with and without the stage tilted as high as 60° are virtually indistinguishable. These strategies allowed the reconstruction to 3 Å resolution of a bacterial RNA polymerase with preferred orientation. Furthermore, we present a quantitative framework that allows cryo-EM practitioners to define an optimal tilt angle for dataset acquisition. These data reinforce the utility of employing stage tilt for data collection and provide quantitative metrics to obtain isotropic maps.
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14
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Cryo-EM structure of the Agrobacteriumtumefaciens T-pilus reveals the importance of positive charges in the lumen. Structure 2022; 31:375-384.e4. [PMID: 36513067 DOI: 10.1016/j.str.2022.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 09/19/2022] [Accepted: 11/14/2022] [Indexed: 12/14/2022]
Abstract
Agrobacterium tumefaciens is a natural genetic engineer that transfers DNA into plants, which is the most applied process for generation of genetically modified plants. DNA transfer is mediated by a type IV secretion system in the cell envelope and extracellular T-pili. We here report the cryo-electron microscopic structures of the T-pilus at 3.2-Å resolution and of the plasmid pKM101-determined N-pilus at 3-Å resolution. Both pili contain a main pilus protein (VirB2 in A. tumefaciens, TraM in pKM101) and phospholipids arranged in a five-start helical assembly. They contain positively charged amino acids in the lumen, and the lipids are positively charged in the T-pilus (phosphatidylcholine) conferring overall positive charge. Mutagenesis of the lumen-exposed Arg91 in VirB2 results in protein destabilization and loss of pilus formation. Our results reveal that different phospholipids can be incorporated into type IV secretion pili and that the charge of the lumen may be of functional importance.
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15
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Fan H, Sun F. Developing Graphene Grids for Cryoelectron Microscopy. Front Mol Biosci 2022; 9:937253. [PMID: 35911962 PMCID: PMC9326159 DOI: 10.3389/fmolb.2022.937253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
Cryogenic electron microscopy (cryo-EM) single particle analysis has become one of the major techniques used to study high-resolution 3D structures of biological macromolecules. Specimens are generally prepared in a thin layer of vitrified ice using a holey carbon grid. However, the sample quality using this type of grid is not always ideal for high-resolution imaging even when the specimens in the test tube behave ideally. Various problems occur during a vitrification procedure, including poor/nonuniform distribution of particles, preferred orientation of particles, specimen denaturation/degradation, high background from thick ice, and beam-induced motion, which have become important bottlenecks in high-resolution structural studies using cryo-EM in many projects. In recent years, grids with support films made of graphene and its derivatives have been developed to efficiently solve these problems. Here, the various advantages of graphene grids over conventional holey carbon film grids, functionalization of graphene support films, production methods of graphene grids, and origins of pristine graphene contamination are reviewed and discussed.
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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, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Fei Sun
- National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Center for Biological Imaging, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- Bioland Laboratory, Guangzhou, China
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16
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Structure deformation and curvature sensing of PIEZO1 in lipid membranes. Nature 2022; 604:377-383. [PMID: 35388220 DOI: 10.1038/s41586-022-04574-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/23/2022] [Indexed: 12/16/2022]
Abstract
PIEZO channels respond to piconewton-scale forces to mediate critical physiological and pathophysiological processes1-5. Detergent-solubilized PIEZO channels form bowl-shaped trimers comprising a central ion-conducting pore with an extracellular cap and three curved and non-planar blades with intracellular beams6-10, which may undergo force-induced deformation within lipid membranes11. However, the structures and mechanisms underlying the gating dynamics of PIEZO channels in lipid membranes remain unresolved. Here we determine the curved and flattened structures of PIEZO1 reconstituted in liposome vesicles, directly visualizing the substantial deformability of the PIEZO1-lipid bilayer system and an in-plane areal expansion of approximately 300 nm2 in the flattened structure. The curved structure of PIEZO1 resembles the structure determined from detergent micelles, but has numerous bound phospholipids. By contrast, the flattened structure exhibits membrane tension-induced flattening of the blade, bending of the beam and detaching and rotating of the cap, which could collectively lead to gating of the ion-conducting pathway. On the basis of the measured in-plane membrane area expansion and stiffness constant of PIEZO1 (ref. 11), we calculate a half maximal activation tension of about 1.9 pN nm-1, matching experimentally measured values. Thus, our studies provide a fundamental understanding of how the notable deformability and structural rearrangement of PIEZO1 achieve exquisite mechanosensitivity and unique curvature-based gating in lipid membranes.
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17
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Huber ST, Sarajlic E, Huijink R, Weis F, Evers WH, Jakobi AJ. Nanofluidic chips for cryo-EM structure determination from picoliter sample volumes. eLife 2022; 11:72629. [PMID: 35060902 PMCID: PMC8786315 DOI: 10.7554/elife.72629] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/07/2021] [Indexed: 01/25/2023] Open
Abstract
Cryogenic electron microscopy has become an essential tool for structure determination of biological macromolecules. In practice, the difficulty to reliably prepare samples with uniform ice thickness still represents a barrier for routine high-resolution imaging and limits the current throughput of the technique. We show that a nanofluidic sample support with well-defined geometry can be used to prepare cryo-EM specimens with reproducible ice thickness from picoliter sample volumes. The sample solution is contained in electron-transparent nanochannels that provide uniform thickness gradients without further optimisation and eliminate the potentially destructive air-water interface. We demonstrate the possibility to perform high-resolution structure determination with three standard protein specimens. Nanofabricated sample supports bear potential to automate the cryo-EM workflow, and to explore new frontiers for cryo-EM applications such as time-resolved imaging and high-throughput screening.
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Affiliation(s)
- Stefan T Huber
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology
| | | | | | - Felix Weis
- Structural and Computational Biology Unit, European Molecular Biology Laboratory (EMBL)
| | - Wiel H Evers
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology
| | - Arjen J Jakobi
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology
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18
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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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19
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Hansen JM, Horowitz A, Lynch EM, Farrell DP, Quispe J, DiMaio F, Kollman JM. Cryo-EM structures of CTP synthase filaments reveal mechanism of pH-sensitive assembly during budding yeast starvation. eLife 2021; 10:73368. [PMID: 34734801 PMCID: PMC8641951 DOI: 10.7554/elife.73368] [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: 08/26/2021] [Accepted: 11/03/2021] [Indexed: 12/27/2022] Open
Abstract
Many metabolic enzymes self-assemble into micron-scale filaments to organize and regulate metabolism. The appearance of these assemblies often coincides with large metabolic changes as in development, cancer, and stress. Yeast undergo cytoplasmic acidification upon starvation, triggering the assembly of many metabolic enzymes into filaments. However, it is unclear how these filaments assemble at the molecular level and what their role is in the yeast starvation response. CTP Synthase (CTPS) assembles into metabolic filaments across many species. Here, we characterize in vitro polymerization and investigate in vivo consequences of CTPS assembly in yeast. Cryo-EM structures reveal a pH-sensitive assembly mechanism and highly ordered filament bundles that stabilize an inactive state of the enzyme, features unique to yeast CTPS. Disruption of filaments in cells with non-assembly or pH-insensitive mutations decreases growth rate, reflecting the importance of regulated CTPS filament assembly in homeotstasis.
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Affiliation(s)
- Jesse M Hansen
- Department of Biochemistry, University of Washington, Seattle, United States.,Graduate Program in Biological Physics, Structure, and Design, University of Washington, Seattle, United States
| | - Avital Horowitz
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Eric M Lynch
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Daniel P Farrell
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Joel Quispe
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Justin M Kollman
- Department of Biochemistry, University of Washington, Seattle, United States
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20
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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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21
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Zhang Z, Shigematsu H, Shimizu T, Ohto U. Improving particle quality in cryo-EM analysis using a PEGylation method. Structure 2021; 29:1192-1199.e4. [PMID: 34048698 DOI: 10.1016/j.str.2021.05.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 02/22/2021] [Accepted: 05/07/2021] [Indexed: 01/30/2023]
Abstract
Cryo-electron microscopy (cryo-EM) is widely used for structural biology studies and has been developed extensively in recent years. However, its sample vitrification process is a major limitation because it causes severe particle aggregation and/or denaturation. This effect is thought to occur because particles tend to stick to the "deadly" air-water interface during vitrification. Here, we report a method for PEGylation of proteins that can efficiently protect particles against such problems during vitrification. This method alleviates the laborious process of fine-tuning the vitrification conditions, allowing for analysis of samples that would otherwise be discarded.
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Affiliation(s)
- Zhikuan Zhang
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Umeharu Ohto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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22
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An overview of the recent advances in cryo-electron microscopy for life sciences. Emerg Top Life Sci 2021; 5:151-168. [PMID: 33760078 DOI: 10.1042/etls20200295] [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: 12/14/2020] [Revised: 02/26/2021] [Accepted: 03/09/2021] [Indexed: 01/18/2023]
Abstract
Cryo-electron microscopy (CryoEM) has superseded X-ray crystallography and NMR to emerge as a popular and effective tool for structure determination in recent times. It has become indispensable for the characterization of large macromolecular assemblies, membrane proteins, or samples that are limited, conformationally heterogeneous, and recalcitrant to crystallization. Besides, it is the only tool capable of elucidating high-resolution structures of macromolecules and biological assemblies in situ. A state-of-the-art electron microscope operable at cryo-temperature helps preserve high-resolution details of the biological sample. The structures can be determined, either in isolation via single-particle analysis (SPA) or helical reconstruction, electron diffraction (ED) or within the cellular environment via cryo-electron tomography (cryoET). All the three streams of SPA, ED, and cryoET (along with subtomogram averaging) have undergone significant advancements in recent times. This has resulted in breaking the boundaries with respect to both the size of the macromolecules/assemblies whose structures could be determined along with the visualization of atomic details at resolutions unprecedented for cryoEM. In addition, the collection of larger datasets combined with the ability to sort and process multiple conformational states from the same sample are providing the much-needed link between the protein structures and their functions. In overview, these developments are helping scientists decipher the molecular mechanism of critical cellular processes, solve structures of macromolecules that were challenging targets for structure determination until now, propelling forward the fields of biology and biomedicine. Here, we summarize recent advances and key contributions of the three cryo-electron microscopy streams of SPA, ED, and cryoET.
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23
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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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24
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Boyoglu-Barnum S, Ellis D, Gillespie RA, Hutchinson GB, Park YJ, Moin SM, Acton OJ, Ravichandran R, Murphy M, Pettie D, Matheson N, Carter L, Creanga A, Watson MJ, Kephart S, Ataca S, Vaile JR, Ueda G, Crank MC, Stewart L, Lee KK, Guttman M, Baker D, Mascola JR, Veesler D, Graham BS, King NP, Kanekiyo M. Quadrivalent influenza nanoparticle vaccines induce broad protection. Nature 2021; 592:623-628. [PMID: 33762730 PMCID: PMC8269962 DOI: 10.1038/s41586-021-03365-x] [Citation(s) in RCA: 168] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/17/2021] [Indexed: 01/15/2023]
Abstract
Influenza vaccines that confer broad and durable protection against diverse viral strains would have a major effect on global health, as they would lessen the need for annual vaccine reformulation and immunization1. Here we show that computationally designed, two-component nanoparticle immunogens2 induce potently neutralizing and broadly protective antibody responses against a wide variety of influenza viruses. The nanoparticle immunogens contain 20 haemagglutinin glycoprotein trimers in an ordered array, and their assembly in vitro enables the precisely controlled co-display of multiple distinct haemagglutinin proteins in defined ratios. Nanoparticle immunogens that co-display the four haemagglutinins of licensed quadrivalent influenza vaccines elicited antibody responses in several animal models against vaccine-matched strains that were equivalent to or better than commercial quadrivalent influenza vaccines, and simultaneously induced broadly protective antibody responses to heterologous viruses by targeting the subdominant yet conserved haemagglutinin stem. The combination of potent receptor-blocking and cross-reactive stem-directed antibodies induced by the nanoparticle immunogens makes them attractive candidates for a supraseasonal influenza vaccine candidate with the potential to replace conventional seasonal vaccines3.
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MESH Headings
- Animals
- Broadly Neutralizing Antibodies/immunology
- Disease Models, Animal
- Female
- Ferrets/immunology
- Ferrets/virology
- Hemagglutinin Glycoproteins, Influenza Virus/chemistry
- Hemagglutinin Glycoproteins, Influenza Virus/immunology
- Humans
- Influenza A Virus, H1N1 Subtype/immunology
- Influenza A Virus, H3N2 Subtype/immunology
- Influenza A virus/classification
- Influenza A virus/immunology
- Influenza Vaccines/administration & dosage
- Influenza Vaccines/chemistry
- Influenza Vaccines/immunology
- Influenza, Human/immunology
- Influenza, Human/prevention & control
- Influenza, Human/virology
- Male
- Mice
- Mice, Inbred BALB C
- Models, Molecular
- Nanomedicine
- Nanoparticles
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Affiliation(s)
- Seyhan Boyoglu-Barnum
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Daniel Ellis
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, WA, USA
| | - Rebecca A Gillespie
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Geoffrey B Hutchinson
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Young-Jun Park
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Syed M Moin
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Oliver J Acton
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Macromolecular Structure Laboratory, The Francis Crick Institute, London, UK
| | - Rashmi Ravichandran
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Mike Murphy
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Deleah Pettie
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Nick Matheson
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Lauren Carter
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Adrian Creanga
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michael J Watson
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Sally Kephart
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Sila Ataca
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - John R Vaile
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - George Ueda
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Michelle C Crank
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Lance Stewart
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Kelly K Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - David Baker
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
| | - John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Barney S Graham
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - Neil P King
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
| | - Masaru Kanekiyo
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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25
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Huang X, Zhang L, Wen Z, Chen H, Li S, Ji G, Yin CC, Sun F. Reprint of "Amorphous nickel titanium alloy film: A new choice for cryo electron microscopy sample preparation". PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 160:5-15. [PMID: 33642056 DOI: 10.1016/j.pbiomolbio.2021.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/14/2020] [Accepted: 07/16/2020] [Indexed: 10/22/2022]
Abstract
Cryo-electron microscopy (cryoEM) has become one of the most important approach for structural biology. However, barriers are still there for an increased successful rate, a better resolution and improved efficiency from sample preparation, data collection to image processing. CryoEM sample preparation is one of the bottlenecks with many efforts made recently, including the optimization of supporting substrate (e.g. ultra-thin carbon, graphene, pure gold, 2d crystal of streptavidin, and affinity modification), which was aimed to solve air-water interface problem, or reduce beam induced motion (BIM), or change particle distribution in the grid hole. Here, we report another effort of developing a new supporting substrate, the amorphous nickel-titanium alloy (ANTA) film, for cryoEM sample preparation as a layer of holey supporting film covering on TEM grid. Our investigations showed advantages of ANTA film in comparison with conventional carbon film, including much better electron conductivity and trace non-specific interaction with protein. These advantages yield less BIM and significantly improved particle distribution during cryoEM experiment of human apo-ferritn, thus resulting an improved reconstruction resolution from a reduced number of micrographs and particles. Unlike the pure gold film, the usage of the ANTA film is just same with the carbon film, compatible to conventional automatic cryoEM data collection procedure.
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Affiliation(s)
- Xiaojun Huang
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Lei Zhang
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China; Electron Microscopy Analysis Laboratory, Medical and Health Analysis Center, Peking University, Beijing, 100191, China
| | - Zuoling Wen
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Chen
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuoguo Li
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Gang Ji
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chang-Cheng Yin
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China; Electron Microscopy Analysis Laboratory, Medical and Health Analysis Center, Peking University, Beijing, 100191, China; Center for Protein Science, Peking University, Beijing, 100871, China
| | - Fei Sun
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China.
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26
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Asymmetrizing an icosahedral virus capsid by hierarchical assembly of subunits with designed asymmetry. Nat Commun 2021; 12:589. [PMID: 33500404 PMCID: PMC7838286 DOI: 10.1038/s41467-020-20862-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 12/07/2020] [Indexed: 11/08/2022] Open
Abstract
Symmetrical protein complexes are ubiquitous in biology. Many have been re-engineered for chemical and medical applications. Viral capsids and their assembly are frequent platforms for these investigations. A means to create asymmetric capsids may expand applications. Here, starting with homodimeric Hepatitis B Virus capsid protein, we develop a heterodimer, design a hierarchical assembly pathway, and produce asymmetric capsids. In the heterodimer, the two halves have different growth potentials and assemble into hexamers. These preformed hexamers can nucleate co-assembly with other dimers, leading to Janus-like capsids with a small discrete hexamer patch. We can remove the patch specifically and observe asymmetric holey capsids by cryo-EM reconstruction. The resulting hole in the surface can be refilled with fluorescently labeled dimers to regenerate an intact capsid. In this study, we show how an asymmetric subunit can be used to generate an asymmetric particle, creating the potential for a capsid with different surface chemistries.
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27
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Persson BD, John L, Rafie K, Strebl M, Frängsmyr L, Ballmann MZ, Mindler K, Havenga M, Lemckert A, Stehle T, Carlson LA, Arnberg N. Human species D adenovirus hexon capsid protein mediates cell entry through a direct interaction with CD46. Proc Natl Acad Sci U S A 2021; 118:e2020732118. [PMID: 33384338 PMCID: PMC7826407 DOI: 10.1073/pnas.2020732118] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Human adenovirus species D (HAdV-D) types are currently being explored as vaccine vectors for coronavirus disease 2019 (COVID-19) and other severe infectious diseases. The efficacy of such vector-based vaccines depends on functional interactions with receptors on host cells. Adenoviruses of different species are assumed to enter host cells mainly by interactions between the knob domain of the protruding fiber capsid protein and cellular receptors. Using a cell-based receptor-screening assay, we identified CD46 as a receptor for HAdV-D56. The function of CD46 was validated in infection experiments using cells lacking and overexpressing CD46, and by competition infection experiments using soluble CD46. Remarkably, unlike HAdV-B types that engage CD46 through interactions with the knob domain of the fiber protein, HAdV-D types infect host cells through a direct interaction between CD46 and the hexon protein. Soluble hexon proteins (but not fiber knob) inhibited HAdV-D56 infection, and surface plasmon analyses demonstrated that CD46 binds to HAdV-D hexon (but not fiber knob) proteins. Cryoelectron microscopy analysis of the HAdV-D56 virion-CD46 complex confirmed the interaction and showed that CD46 binds to the central cavity of hexon trimers. Finally, soluble CD46 inhibited infection by 16 out of 17 investigated HAdV-D types, suggesting that CD46 is an important receptor for a large group of adenoviruses. In conclusion, this study identifies a noncanonical entry mechanism used by human adenoviruses, which adds to the knowledge of adenovirus biology and can also be useful for development of adenovirus-based vaccine vectors.
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Affiliation(s)
- B David Persson
- Department of Clinical Microbiology, Division of Virology, Umeå University, SE-90185 Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, SE-90185 Umeå, Sweden
| | - Lijo John
- Department of Clinical Microbiology, Division of Virology, Umeå University, SE-90185 Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, SE-90185 Umeå, Sweden
| | - Karim Rafie
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, SE-90185 Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, SE-90187 Umeå, Sweden
- Department of Medical Biochemistry, Umeå University, SE-90187 Umeå, Sweden
| | - Michael Strebl
- Interfaculty Institute of Biochemistry, The University of Tübingen, D-72076 Tübingen, Germany
| | - Lars Frängsmyr
- Department of Clinical Microbiology, Division of Virology, Umeå University, SE-90185 Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, SE-90185 Umeå, Sweden
| | | | - Katja Mindler
- Interfaculty Institute of Biochemistry, The University of Tübingen, D-72076 Tübingen, Germany
| | - Menzo Havenga
- Batavia Biosciences, 2333 CL Leiden, The Netherlands
| | | | - Thilo Stehle
- Interfaculty Institute of Biochemistry, The University of Tübingen, D-72076 Tübingen, Germany
| | - Lars-Anders Carlson
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, SE-90185 Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, SE-90187 Umeå, Sweden
- Department of Medical Biochemistry, Umeå University, SE-90187 Umeå, Sweden
| | - Niklas Arnberg
- Department of Clinical Microbiology, Division of Virology, Umeå University, SE-90185 Umeå, Sweden;
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, SE-90185 Umeå, Sweden
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28
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Rafie K, Lenman A, Fuchs J, Rajan A, Arnberg N, Carlson LA. The structure of enteric human adenovirus 41-A leading cause of diarrhea in children. SCIENCE ADVANCES 2021; 7:7/2/eabe0974. [PMID: 33523995 PMCID: PMC7793593 DOI: 10.1126/sciadv.abe0974] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/17/2020] [Indexed: 05/05/2023]
Abstract
Human adenovirus (HAdV) types F40 and F41 are a prominent cause of diarrhea and diarrhea-associated mortality in young children worldwide. These enteric HAdVs differ notably in tissue tropism and pathogenicity from respiratory and ocular adenoviruses, but the structural basis for this divergence has been unknown. Here, we present the first structure of an enteric HAdV-HAdV-F41-determined by cryo-electron microscopy to a resolution of 3.8 Å. The structure reveals extensive alterations to the virion exterior as compared to nonenteric HAdVs, including a unique arrangement of capsid protein IX. The structure also provides new insights into conserved aspects of HAdV architecture such as a proposed location of core protein V, which links the viral DNA to the capsid, and assembly-induced conformational changes in the penton base protein. Our findings provide the structural basis for adaptation of enteric HAdVs to a fundamentally different tissue tropism.
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Affiliation(s)
- K Rafie
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - A Lenman
- Department of Clinical Microbiology, Section of Virology, Umeå University, Umeå, Sweden
- Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| | - J Fuchs
- Proteomics Core Facility at Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - A Rajan
- Department of Clinical Microbiology, Section of Virology, Umeå University, Umeå, Sweden
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - N Arnberg
- Department of Clinical Microbiology, Section of Virology, Umeå University, Umeå, Sweden.
| | - L-A Carlson
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
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29
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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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30
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Yao X, Fan X, Yan N. Cryo-EM analysis of a membrane protein embedded in the liposome. Proc Natl Acad Sci U S A 2020; 117:18497-18503. [PMID: 32680969 PMCID: PMC7414195 DOI: 10.1073/pnas.2009385117] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Membrane proteins (MPs) used to be the most difficult targets for structural biology when X-ray crystallography was the mainstream approach. With the resolution revolution of single-particle electron cryo-microscopy (cryo-EM), rapid progress has been made for structural elucidation of isolated MPs. The next challenge is to preserve the electrochemical gradients and membrane curvature for a comprehensive structural elucidation of MPs that rely on these chemical and physical properties for their biological functions. Toward this goal, here we present a convenient workflow for cryo-EM structural analysis of MPs embedded in liposomes, using the well-characterized AcrB as a prototype. Combining optimized proteoliposome isolation, cryo-sample preparation on graphene grids, and an efficient particle selection strategy, the three-dimensional (3D) reconstruction of AcrB embedded in liposomes was obtained at 3.9 Å resolution. The conformation of the homotrimeric AcrB remains the same when the surrounding membranes display different curvatures. Our approach, which can be widely applied to cryo-EM analysis of MPs with distinctive soluble domains, lays out the foundation for cryo-EM analysis of integral or peripheral MPs whose functions are affected by transmembrane electrochemical gradients or/and membrane curvatures.
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Affiliation(s)
- Xia Yao
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Xiao Fan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
| | - Nieng Yan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544
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31
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Huang X, Zhang L, Wen Z, Chen H, Li S, Ji G, Yin CC, Sun F. Amorphous nickel titanium alloy film: A new choice for cryo electron microscopy sample preparation. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 156:3-13. [PMID: 32758492 DOI: 10.1016/j.pbiomolbio.2020.07.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/14/2020] [Accepted: 07/16/2020] [Indexed: 11/19/2022]
Abstract
Cryo-electron microscopy (cryoEM) has become one of the most important approach for structural biology. However, barriers are still there for an increased successful rate, a better resolution and improved efficiency from sample preparation, data collection to image processing. CryoEM sample preparation is one of the bottlenecks with many efforts made recently, including the optimization of supporting substrate (e.g. ultra-thin carbon, graphene, pure gold, 2d crystal of streptavidin, and affinity modification), which was aimed to solve air-water interface problem, or reduce beam induced motion (BIM), or change particle distribution in the grid hole. Here, we report another effort of developing a new supporting substrate, the amorphous nickel-titanium alloy (ANTA) film, for cryoEM sample preparation as a layer of holey supporting film covering on TEM grid. Our investigations showed advantages of ANTA film in comparison with conventional carbon film, including much better electron conductivity and trace non-specific interaction with protein. These advantages yield less BIM and significantly improved particle distribution during cryoEM experiment of human apo-ferritn, thus resulting an improved reconstruction resolution from a reduced number of micrographs and particles. Unlike the pure gold film, the usage of the ANTA film is just same with the carbon film, compatible to conventional automatic cryoEM data collection procedure.
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Affiliation(s)
- Xiaojun Huang
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Lei Zhang
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China; Electron Microscopy Analysis Laboratory, Medical and Health Analysis Center, Peking University, Beijing, 100191, China
| | - Zuoling Wen
- College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Chen
- Key Laboratory of RNA Biology, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuoguo Li
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Gang Ji
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Chang-Cheng Yin
- Department of Biophysics, The Health Science Center, Peking University, Beijing, 100191, China; Electron Microscopy Analysis Laboratory, Medical and Health Analysis Center, Peking University, Beijing, 100191, China; Center for Protein Science, Peking University, Beijing, 100871, China
| | - Fei Sun
- Center for Biological Imaging, Core Facilities for Protein Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; National Key Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; College of Life Science, University of Chinese Academy of Sciences, Beijing, 100049, China.
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32
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Al-Otaibi NS, Taylor AJ, Farrell DP, Tzokov SB, DiMaio F, Kelly DJ, Bergeron JRC. The cryo-EM structure of the bacterial flagellum cap complex suggests a molecular mechanism for filament elongation. Nat Commun 2020; 11:3210. [PMID: 32587243 PMCID: PMC7316729 DOI: 10.1038/s41467-020-16981-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 05/29/2020] [Indexed: 11/16/2022] Open
Abstract
The bacterial flagellum is a remarkable molecular motor, whose primary function in bacteria is to facilitate motility through the rotation of a filament protruding from the bacterial cell. A cap complex, consisting of an oligomer of the protein FliD, is localized at the tip of the flagellum, and is essential for filament assembly, as well as adherence to surfaces in some bacteria. However, the structure of the intact cap complex, and the molecular basis for its interaction with the filament, remains elusive. Here we report the cryo-EM structure of the Campylobacter jejuni cap complex, which reveals that FliD is pentameric, with the N-terminal region of the protomer forming an extensive set of contacts across several subunits, that contribute to FliD oligomerization. We also demonstrate that the native C. jejuni flagellum filament is 11-stranded, contrary to a previously published cryo-EM structure, and propose a molecular model for the filament-cap interaction. FliD forms a cap complex at the tip of bacterial flagella and is essential for flagellum filament assembly. Here, the authors present the cryo-EM structure of the Campylobacter jejuni cap complex, revealing a pentameric assembly of FliD and further show that the C. jejuni flagellum filament is 11-stranded.
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Affiliation(s)
- Natalie S Al-Otaibi
- Department of Molecular Biology and Biotechnology, the University of Sheffield, Sheffield, UK
| | - Aidan J Taylor
- Department of Molecular Biology and Biotechnology, the University of Sheffield, Sheffield, UK
| | - Daniel P Farrell
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Svetomir B Tzokov
- Department of Molecular Biology and Biotechnology, the University of Sheffield, Sheffield, UK
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - David J Kelly
- Department of Molecular Biology and Biotechnology, the University of Sheffield, Sheffield, UK.
| | - Julien R C Bergeron
- Department of Molecular Biology and Biotechnology, the University of Sheffield, Sheffield, UK. .,Randall Division of Cell and Molecular Biophysics, King's College London, London, UK.
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33
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Wang F, Yu Z, Betegon M, Campbell MG, Aksel T, Zhao J, Li S, Douglas SM, Cheng Y, Agard DA. Amino and PEG-amino graphene oxide grids enrich and protect samples for high-resolution single particle cryo-electron microscopy. J Struct Biol 2020; 209:107437. [PMID: 31866389 PMCID: PMC7272056 DOI: 10.1016/j.jsb.2019.107437] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 12/15/2019] [Accepted: 12/17/2019] [Indexed: 11/29/2022]
Abstract
Cryo-EM samples prepared using traditional methods often suffer from too few particles, poor particle distribution, strongly biased orientation, or damage from the air-water interface. Here we report that functionalization of graphene oxide (GO) coated grids with amino groups concentrates samples on the grid with improved distribution and orientation. By introducing a PEG spacer, particles are kept away from both the GO surface and the air-water interface, protecting them from potential denaturation.
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Affiliation(s)
- Feng Wang
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Zanlin Yu
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Miguel Betegon
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Melody G Campbell
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Tural Aksel
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, United States
| | - Jianhua Zhao
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Sam Li
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Shawn M Douglas
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, United States
| | - Yifan Cheng
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States
| | - David A Agard
- Department of Biochemistry & Biophysics and the Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, United States.
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34
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Wieczorek M, Urnavicius L, Ti SC, Molloy KR, Chait BT, Kapoor TM. Asymmetric Molecular Architecture of the Human γ-Tubulin Ring Complex. Cell 2020; 180:165-175.e16. [PMID: 31862189 PMCID: PMC7027161 DOI: 10.1016/j.cell.2019.12.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 11/21/2019] [Accepted: 12/07/2019] [Indexed: 10/25/2022]
Abstract
The γ-tubulin ring complex (γ-TuRC) is an essential regulator of centrosomal and acentrosomal microtubule formation, yet its structure is not known. Here, we present a cryo-EM reconstruction of the native human γ-TuRC at ∼3.8 Å resolution, revealing an asymmetric, cone-shaped structure. Pseudo-atomic models indicate that GCP4, GCP5, and GCP6 form distinct Y-shaped assemblies that structurally mimic GCP2/GCP3 subcomplexes distal to the γ-TuRC "seam." We also identify an unanticipated structural bridge that includes an actin-like protein and spans the γ-TuRC lumen. Despite its asymmetric architecture, the γ-TuRC arranges γ-tubulins into a helical geometry poised to nucleate microtubules. Diversity in the γ-TuRC subunits introduces large (>100,000 Å2) surfaces in the complex that allow for interactions with different regulatory factors. The observed compositional complexity of the γ-TuRC could self-regulate its assembly into a cone-shaped structure to control microtubule formation across diverse contexts, e.g., within biological condensates or alongside existing filaments.
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Affiliation(s)
- Michal Wieczorek
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Linas Urnavicius
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Laboratory of Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Shih-Chieh Ti
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Kelly R Molloy
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Tarun M Kapoor
- Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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35
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Kalienkova V, Alvadia C, Clerico Mosina V, Paulino C. Single-Particle Cryo-EM of Membrane Proteins in Lipid Nanodiscs. Methods Mol Biol 2020; 2127:245-273. [PMID: 32112327 DOI: 10.1007/978-1-0716-0373-4_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Single-particle cryo-electron microscopy has become an indispensable technique in structural biology. In particular when studying membrane proteins, it allows the use of membrane-mimicking tools, which can be crucial for a comprehensive understanding of the structure-function relationship of the protein in its native environment. In this chapter we focus on the application of nanodiscs and use our recent studies on the TMEM16 family as an example.
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Affiliation(s)
- Valeria Kalienkova
- Department of Structural Biology at the Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Carolina Alvadia
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Vanessa Clerico Mosina
- Department of Structural Biology at the Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
| | - Cristina Paulino
- Department of Structural Biology at the Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
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36
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Tonggu L, Wang L. Cryo-EM sample preparation method for extremely low concentration liposomes. Ultramicroscopy 2020; 208:112849. [PMID: 31622807 PMCID: PMC7058178 DOI: 10.1016/j.ultramic.2019.112849] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/01/2019] [Accepted: 09/29/2019] [Indexed: 12/16/2022]
Abstract
Liposomes are widely used as delivery systems in pharmaceutical, cosmetics and food industries, as well as a system for structural and functional study of membrane proteins. To accurately characterize liposomes, cryo-Electron Microscopy (cryo-EM) has been employed as it is the most precise and direct method to determine liposome lamellarity, size, shape and ultrastructure. However, its use is limited by the number of liposomes that can be trapped in the thin layer of ice that spans holes in the perforated carbon film on EM grids. We report a long-incubation method for increasing the density of liposomes in holes. By increasing the incubation time, high liposome density was achieved even with extremely dilute (in the nanomolar range) liposome solutions. This long-incubation method has been successfully employed to study the structure of an ion channel reconstituted into liposomes.
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Affiliation(s)
- Lige Tonggu
- Department of Biological Structure, University of Washington, Seattle, WA 98195, United States
| | - Liguo Wang
- Department of Biological Structure, University of Washington, Seattle, WA 98195, United States.
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37
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Martín-González N, Hernando-Pérez M, Condezo GN, Pérez-Illana M, Šiber A, Reguera D, Ostapchuk P, Hearing P, San Martín C, de Pablo PJ. Adenovirus major core protein condenses DNA in clusters and bundles, modulating genome release and capsid internal pressure. Nucleic Acids Res 2019; 47:9231-9242. [PMID: 31396624 PMCID: PMC6755088 DOI: 10.1093/nar/gkz687] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 07/10/2019] [Accepted: 08/06/2019] [Indexed: 11/23/2022] Open
Abstract
Some viruses package dsDNA together with large amounts of positively charged proteins, thought to help condense the genome inside the capsid with no evidence. Further, this role is not clear because these viruses have typically lower packing fractions than viruses encapsidating naked dsDNA. In addition, it has recently been shown that the major adenovirus condensing protein (polypeptide VII) is dispensable for genome encapsidation. Here, we study the morphology and mechanics of adenovirus particles with (Ad5-wt) and without (Ad5-VII-) protein VII. Ad5-VII- particles are stiffer than Ad5-wt, but DNA-counterions revert this difference, indicating that VII screens repulsive DNA-DNA interactions. Consequently, its absence results in increased internal pressure. The core is slightly more ordered in the absence of VII and diffuses faster out of Ad5-VII– than Ad5-wt fractured particles. In Ad5-wt unpacked cores, dsDNA associates in bundles interspersed with VII-DNA clusters. These results indicate that protein VII condenses the adenovirus genome by combining direct clustering and promotion of bridging by other core proteins. This condensation modulates the virion internal pressure and DNA release from disrupted particles, which could be crucial to keep the genome protected inside the semi-disrupted capsid while traveling to the nuclear pore.
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Affiliation(s)
| | - Mercedes Hernando-Pérez
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), Madrid 28049, Spain
| | - Gabriela N Condezo
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), Madrid 28049, Spain
| | - Marta Pérez-Illana
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), Madrid 28049, Spain
| | | | - David Reguera
- Departament de Física de la Matèria Condensada, Facultat de Física, Universitat de Barcelona, Martí i Franqués 1, 08028 Barcelona, Spain.,Universitat de Barcelona Institute of Complex Systems (UBICS), 08028 Barcelona, Spain
| | - Philomena Ostapchuk
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, NY 11794-5222, USA
| | - Patrick Hearing
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, NY 11794-5222, USA
| | - Carmen San Martín
- Department of Macromolecular Structures, Centro Nacional de Biotecnología (CNB-CSIC), Madrid 28049, Spain
| | - Pedro J de Pablo
- Department of Condensed Matter Physics, Universidad Autónoma de Madrid, Madrid 28049, Spain.,Instituto de Física de la Materia Condensada (IFIMAC), Universidad Autónoma de Madrid, Madrid 28049, Spain
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38
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Carragher B, Cheng Y, Frost A, Glaeser RM, Lander GC, Nogales E, Wang HW. Current outcomes when optimizing 'standard' sample preparation for single-particle cryo-EM. J Microsc 2019; 276:39-45. [PMID: 31553060 PMCID: PMC7050573 DOI: 10.1111/jmi.12834] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/10/2019] [Accepted: 09/19/2019] [Indexed: 12/27/2022]
Abstract
Although high-resolution single-particle cryo-electron microscopy (cryo-EM) is now producing a rapid stream of breakthroughs in structural biology, it nevertheless remains the case that the preparation of suitable frozen-hydrated samples on electron microscopy grids is often quite challenging. Purified samples that are intact and structurally homogeneous - while still in the test tube - may not necessarily survive the standard methods of making extremely thin, aqueous films on grids. As a result, it is often necessary to try a variety of experimental conditions before finally finding an approach that is optimal for the specimen at hand. Here, we summarize some of our collective experiences to date in optimizing sample preparation, in the hope that doing so will be useful to others, especially those new to the field. We also hope that an open discussion of these common challenges will encourage the development of more generally applicable methodology. Our collective experiences span a diverse range of biochemical samples and most of the commonly used variations in how grids are currently prepared. Unfortunately, none of the currently used optimization methods can be said, in advance, to be the one that ultimately will work when a project first begins. Nevertheless, there are some preferred first steps to explore when facing specific problems that can be more generally recommended, based on our experience and that of many others in the cryo-EM field.
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Affiliation(s)
- B Carragher
- Simon Electron Microscopy Center, New York Structural Biology Center, New York, U.S.A
| | - Y Cheng
- HHMI and Department of Biochemistry and Biophysics, University of California, San Francisco, California, U.S.A
| | - A Frost
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, U.S.A
| | - R M Glaeser
- Lawrence Berkeley National Laboratory, University of California, Berkeley, California, U.S.A
| | - G C Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, California, U.S.A
| | - E Nogales
- Molecular and Cell Biology Department, University of California Berkeley, Berkeley, California, U.S.A
- MBIB Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California, U.S.A
- Howard Hughes Medical Institute, University of California Berkeley, Berkeley, California, U.S.A
| | - H-W Wang
- Ministry of Education Key Laboratory of Protein Sciences, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center of Biological Structures, School of Life Sciences, Tsinghua University, Beijing, China
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39
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Abstract
Cryogenic electron microscopy (cryo-EM) enables structure determination of macromolecular objects and their assemblies. Although the techniques have been developing for nearly four decades, they have gained widespread attention in recent years due to technical advances on numerous fronts, enabling traditional microscopists to break into the world of molecular structural biology. Many samples can now be routinely analyzed at near-atomic resolution using standard imaging and image analysis techniques. However, numerous challenges to conventional workflows remain, and continued technical advances open entirely novel opportunities for discovery and exploration. Here, I will review some of the main methods surrounding cryo-EM with an emphasis specifically on single-particle analysis, and I will highlight challenges, open questions, and opportunities for methodology development.
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Affiliation(s)
- Dmitry Lyumkis
- From the Laboratory of Genetics and Helmsley Center for Genomic Medicine, The Salk Institute for Biological Studies, La Jolla, California 92037
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40
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Marcandalli J, Fiala B, Ols S, Perotti M, de van der Schueren W, Snijder J, Hodge E, Benhaim M, Ravichandran R, Carter L, Sheffler W, Brunner L, Lawrenz M, Dubois P, Lanzavecchia A, Sallusto F, Lee KK, Veesler D, Correnti CE, Stewart LJ, Baker D, Loré K, Perez L, King NP. Induction of Potent Neutralizing Antibody Responses by a Designed Protein Nanoparticle Vaccine for Respiratory Syncytial Virus. Cell 2019; 176:1420-1431.e17. [PMID: 30849373 PMCID: PMC6424820 DOI: 10.1016/j.cell.2019.01.046] [Citation(s) in RCA: 303] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/26/2018] [Accepted: 01/25/2019] [Indexed: 12/11/2022]
Abstract
Respiratory syncytial virus (RSV) is a worldwide public health concern for which no vaccine is available. Elucidation of the prefusion structure of the RSV F glycoprotein and its identification as the main target of neutralizing antibodies have provided new opportunities for development of an effective vaccine. Here, we describe the structure-based design of a self-assembling protein nanoparticle presenting a prefusion-stabilized variant of the F glycoprotein trimer (DS-Cav1) in a repetitive array on the nanoparticle exterior. The two-component nature of the nanoparticle scaffold enabled the production of highly ordered, monodisperse immunogens that display DS-Cav1 at controllable density. In mice and nonhuman primates, the full-valency nanoparticle immunogen displaying 20 DS-Cav1 trimers induced neutralizing antibody responses ∼10-fold higher than trimeric DS-Cav1. These results motivate continued development of this promising nanoparticle RSV vaccine candidate and establish computationally designed two-component nanoparticles as a robust and customizable platform for structure-based vaccine design.
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Affiliation(s)
- Jessica Marcandalli
- Università della Svizzera italiana, Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Bellinzona, Switzerland
| | - Brooke Fiala
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Sebastian Ols
- Department of Medicine Solna, Division of Immunology and Allergy, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Michela Perotti
- Università della Svizzera italiana, Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Bellinzona, Switzerland; Institute of Microbiology, ETH Zürich, Switzerland
| | | | - Joost Snijder
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Edgar Hodge
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Mark Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA
| | - Rashmi Ravichandran
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Lauren Carter
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Will Sheffler
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Livia Brunner
- Vaccine Formulation Laboratory, University of Lausanne, Epalinges, Switzerland
| | | | | | - Antonio Lanzavecchia
- Università della Svizzera italiana, Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Bellinzona, Switzerland
| | - Federica Sallusto
- Università della Svizzera italiana, Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Bellinzona, Switzerland; Institute of Microbiology, ETH Zürich, Switzerland
| | - Kelly K Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA, USA; Biological Physics Structure and Design Program, University of Washington, Seattle, WA, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Colin E Correnti
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Lance J Stewart
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA, USA; Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
| | - Karin Loré
- Department of Medicine Solna, Division of Immunology and Allergy, Karolinska Institutet, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Laurent Perez
- Università della Svizzera italiana, Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Bellinzona, Switzerland; European Virus Bioinformatics Center, Jena, Germany.
| | - Neil P King
- Department of Biochemistry, University of Washington, Seattle, WA, USA; Institute for Protein Design, University of Washington, Seattle, WA, USA.
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41
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Liu N, Zhang J, Chen Y, Liu C, Zhang X, Xu K, Wen J, Luo Z, Chen S, Gao P, Jia K, Liu Z, Peng H, Wang HW. Bioactive Functionalized Monolayer Graphene for High-Resolution Cryo-Electron Microscopy. J Am Chem Soc 2019; 141:4016-4025. [DOI: 10.1021/jacs.8b13038] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Peng Gao
- Collaborative Innovation Center of Quantum Matter, Beijing 100871, China
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42
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Cheung M, Adaniya H, Cassidy C, Yamashita M, Li KL, Taba S, Shintake T. Improved sample dispersion in cryo-EM using “perpetually-hydrated” graphene oxide flakes. J Struct Biol 2018; 204:75-79. [DOI: 10.1016/j.jsb.2018.07.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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43
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Zhang C, Konermann S, Brideau NJ, Lotfy P, Wu X, Novick SJ, Strutzenberg T, Griffin PR, Hsu PD, Lyumkis D. Structural Basis for the RNA-Guided Ribonuclease Activity of CRISPR-Cas13d. Cell 2018; 175:212-223.e17. [PMID: 30241607 PMCID: PMC6179368 DOI: 10.1016/j.cell.2018.09.001] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/01/2018] [Accepted: 09/04/2018] [Indexed: 12/11/2022]
Abstract
CRISPR-Cas endonucleases directed against foreign nucleic acids mediate prokaryotic adaptive immunity and have been tailored for broad genetic engineering applications. Type VI-D CRISPR systems contain the smallest known family of single effector Cas enzymes, and their signature Cas13d ribonuclease employs guide RNAs to cleave matching target RNAs. To understand the molecular basis for Cas13d function and explain its compact molecular architecture, we resolved cryoelectron microscopy structures of Cas13d-guide RNA binary complex and Cas13d-guide-target RNA ternary complex to 3.4 and 3.3 Å resolution, respectively. Furthermore, a 6.5 Å reconstruction of apo Cas13d combined with hydrogen-deuterium exchange revealed conformational dynamics that have implications for RNA scanning. These structures, together with biochemical and cellular characterization, provide insights into its RNA-guided, RNA-targeting mechanism and delineate a blueprint for the rational design of improved transcriptome engineering technologies.
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Affiliation(s)
- Cheng Zhang
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA; Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Silvana Konermann
- Laboratory of Molecular and Cell Biology, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA; Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Nicholas J Brideau
- Laboratory of Molecular and Cell Biology, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA; Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Peter Lotfy
- Laboratory of Molecular and Cell Biology, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA; Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA
| | - Xuebing Wu
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA
| | - Scott J Novick
- Department of Molecular Medicine, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Timothy Strutzenberg
- Department of Molecular Medicine, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Patrick R Griffin
- Department of Molecular Medicine, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458, USA
| | - Patrick D Hsu
- Laboratory of Molecular and Cell Biology, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA; Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA.
| | - Dmitry Lyumkis
- Laboratory of Genetics, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA; Helmsley Center for Genomic Medicine, Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, CA 92037, USA.
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44
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Sub-2 Å Ewald curvature corrected structure of an AAV2 capsid variant. Nat Commun 2018; 9:3628. [PMID: 30194371 PMCID: PMC6128836 DOI: 10.1038/s41467-018-06076-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 08/11/2018] [Indexed: 01/08/2023] Open
Abstract
Single-particle cryogenic electron microscopy (cryo-EM) provides a powerful methodology for structural biologists, but the resolutions typically attained with experimentally determined structures have lagged behind microscope capabilities. Here, we exploit several technical advances to improve resolution, including per-particle contrast transfer function (CTF) refinement and correction for Ewald sphere curvature. The latter is demonstrated with several experimental samples and should become more standard as resolutions increase or at lower microscope accelerating voltages. The combined application of the described methods to micrographs recorded on a Titan Krios enables structure determination at ~1.86-Å resolution of an adeno-associated virus serotype 2 variant (AAV2), an important gene-delivery vehicle. The resulting structural details provide an improved model for understanding the biology of AAV that will guide future vector development for gene therapy. Single-particle cryo-EM is a powerful method for macromolecular structure determination. Here the authors demonstrate that Ewald sphere curvature correction, sub-Angstrom pixilation and per-particle CTF refinement can improve map quality and resolution and present the 1.86 Å cryo-EM structure of an adeno-associated virus serotype 2 variant.
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45
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Palovcak E, Wang F, Zheng SQ, Yu Z, Li S, Betegon M, Bulkley D, Agard DA, Cheng Y. A simple and robust procedure for preparing graphene-oxide cryo-EM grids. J Struct Biol 2018; 204:80-84. [PMID: 30017701 DOI: 10.1016/j.jsb.2018.07.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 07/05/2018] [Accepted: 07/11/2018] [Indexed: 02/04/2023]
Abstract
Graphene oxide (GO) sheets have been used successfully as a supporting substrate film in several recent cryogenic electron-microscopy (cryo-EM) studies of challenging biological macromolecules. However, difficulties in preparing GO-covered holey carbon EM grids have limited their widespread use. Here, we report a simple and robust method for covering holey carbon EM grids with GO sheets and demonstrate that these grids can be used for high-resolution single particle cryo-EM. GO substrates adhere macromolecules, allowing cryo-EM grid preparation with lower specimen concentrations and provide partial protection from the air-water interface. Additionally, the signal of the GO lattice beneath the frozen-hydrated specimen can be discerned in many motion-corrected micrographs, providing a high-resolution fiducial for evaluating beam-induced motion correction.
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Affiliation(s)
- Eugene Palovcak
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States
| | - Feng Wang
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States
| | - Shawn Q Zheng
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94143, United States
| | - Zanlin Yu
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States
| | - Sam Li
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States
| | - Miguel Betegon
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States
| | - David Bulkley
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States
| | - David A Agard
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94143, United States.
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco, CA 94143, United States; Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA 94143, United States.
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Snijder J, Ortego MS, Weidle C, Stuart AB, Gray MD, McElrath MJ, Pancera M, Veesler D, McGuire AT. An Antibody Targeting the Fusion Machinery Neutralizes Dual-Tropic Infection and Defines a Site of Vulnerability on Epstein-Barr Virus. Immunity 2018; 48:799-811.e9. [PMID: 29669253 PMCID: PMC5909843 DOI: 10.1016/j.immuni.2018.03.026] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 01/18/2018] [Accepted: 03/23/2018] [Indexed: 01/01/2023]
Abstract
Epstein-Barr virus (EBV) is a causative agent of infectious mononucleosis and is associated with 200,000 new cases of cancer and 140,000 deaths annually. Subunit vaccines against this pathogen have focused on the gp350 glycoprotein and remain unsuccessful. We isolated human antibodies recognizing the EBV fusion machinery (gH/gL and gB) from rare memory B cells. One anti-gH/gL antibody, AMMO1, potently neutralized infection of B cells and epithelial cells, the two major cell types targeted by EBV. We determined a cryo-electron microscopy reconstruction of the gH/gL-gp42-AMMO1 complex and demonstrated that AMMO1 bound to a discontinuous epitope formed by both gH and gL at the Domain-I/Domain-II interface. Integrating structural, biochemical, and infectivity data, we propose that AMMO1 inhibits fusion of the viral and cellular membranes. This work identifies a crucial epitope that may aid in the design of next-generation subunit vaccines against this major public health burden.
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Affiliation(s)
- Joost Snijder
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Michael S Ortego
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA
| | - Connor Weidle
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA
| | - Andrew B Stuart
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA
| | - Matthew D Gray
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA
| | - M Juliana McElrath
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Marie Pancera
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA
| | - David Veesler
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA.
| | - Andrew T McGuire
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N. PO Box 19024, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA.
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Cheung M, Adaniya H, Cassidy C, Yamashita M, Li KL, Taba S, Shintake T. Improved sample dispersion in cryo-EM using "perpetually-hydrated" graphene oxide flakes. J Struct Biol 2018:S1047-8477(18)30083-2. [PMID: 29551713 DOI: 10.1016/j.jsb.2018.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 01/08/2023]
Abstract
For many macromolecular complexes, the inability to uniformly disperse solubilized specimen particles within vitreous ice films precludes their analysis by cryo-electron microscopy (cryo-EM). Here, we introduce a sample preparation process using "perpetually-hydrated" graphene oxide flakes as particle support films, and report vastly improved specimen dispersion. Furthermore, we provide evidence that the presence of graphene oxide flakes in vitreous ice results in a significant reduction in electron beam-induced specimen decomposition. The new method introduced in this study incorporates hydrated graphene oxide flakes into a standard sample preparation regime, without the need for additional tools or devices, making it a cost-effective and easily adoptable alternative to currently available sample preparation approaches.
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Affiliation(s)
- Martin Cheung
- Quantum Wave Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami District Okinawa Prefecture, 904-0412 Japan.
| | - Hidehito Adaniya
- Quantum Wave Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami District Okinawa Prefecture, 904-0412 Japan
| | - Cathal Cassidy
- Quantum Wave Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami District Okinawa Prefecture, 904-0412 Japan
| | - Masao Yamashita
- Quantum Wave Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami District Okinawa Prefecture, 904-0412 Japan
| | - Kun-Lung Li
- Quantum Wave Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami District Okinawa Prefecture, 904-0412 Japan
| | - Seita Taba
- Quantum Wave Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami District Okinawa Prefecture, 904-0412 Japan
| | - Tsumoru Shintake
- Quantum Wave Microscopy Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami District Okinawa Prefecture, 904-0412 Japan
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Glycan Shield and Fusion Activation of a Deltacoronavirus Spike Glycoprotein Fine-Tuned for Enteric Infections. J Virol 2018; 92:JVI.01628-17. [PMID: 29093093 DOI: 10.1128/jvi.01628-17] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 10/23/2017] [Indexed: 01/10/2023] Open
Abstract
Coronaviruses recently emerged as major human pathogens causing outbreaks of severe acute respiratory syndrome and Middle East respiratory syndrome. They utilize the spike (S) glycoprotein anchored in the viral envelope to mediate host attachment and fusion of the viral and cellular membranes to initiate infection. The S protein is a major determinant of the zoonotic potential of coronaviruses and is also the main target of the host humoral immune response. We report here the 3.5-Å-resolution cryo-electron microscopy structure of the S glycoprotein trimer from the pathogenic porcine deltacoronavirus (PDCoV), which belongs to the recently identified Deltacoronavirus genus. Structural and glycoproteomics data indicate that the glycans of PDCoV S are topologically conserved compared with the human respiratory coronavirus NL63 S, resulting in similar surface areas being shielded from neutralizing antibodies and implying that both viruses are under comparable immune pressure in their respective hosts. The structure further reveals a shortened S2' activation loop, containing a reduced number of basic amino acids, which participates in rendering the spike largely protease resistant. This property distinguishes PDCoV S from recently characterized betacoronavirus S proteins and suggests that the S protein of enterotropic PDCoV has evolved to tolerate the protease-rich environment of the small intestine and to fine-tune its fusion activation to avoid premature triggering and reduction of infectivity.IMPORTANCE Coronaviruses use transmembrane S glycoprotein trimers to promote host attachment and fusion of the viral and cellular membranes. We determined a near-atomic-resolution cryo-electron microscopy structure of the S ectodomain trimer from the pathogenic PDCoV, which is responsible for diarrhea in piglets and has had devastating consequences for the swine industry worldwide. Structural and glycoproteomics data reveal that PDCoV S is decorated with 78 N-linked glycans obstructing the protein surface to limit accessibility to neutralizing antibodies in a way reminiscent of what has recently been described for a human respiratory coronavirus. PDCoV S is largely protease resistant, which distinguishes it from most other characterized coronavirus S glycoproteins and suggests that enteric coronaviruses have evolved to fine-tune fusion activation in the protease-rich environment of the small intestine of infected hosts.
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Tectonic conformational changes of a coronavirus spike glycoprotein promote membrane fusion. Proc Natl Acad Sci U S A 2017; 114:11157-11162. [PMID: 29073020 DOI: 10.1073/pnas.1708727114] [Citation(s) in RCA: 414] [Impact Index Per Article: 59.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The tremendous pandemic potential of coronaviruses was demonstrated twice in the past few decades by two global outbreaks of deadly pneumonia. The coronavirus spike (S) glycoprotein initiates infection by promoting fusion of the viral and cellular membranes through conformational changes that remain largely uncharacterized. Here we report the cryoEM structure of a coronavirus S glycoprotein in the postfusion state, showing large-scale secondary, tertiary, and quaternary rearrangements compared with the prefusion trimer and rationalizing the free-energy landscape of this conformational machine. We also biochemically characterized the molecular events associated with refolding of the metastable prefusion S glycoprotein to the postfusion conformation using limited proteolysis, mass spectrometry, and single-particle EM. The observed similarity between postfusion coronavirus S and paramyxovirus F structures demonstrates that a conserved refolding trajectory mediates entry of these viruses and supports the evolutionary relatedness of their fusion subunits. Finally, our data provide a structural framework for understanding the mode of neutralization of antibodies targeting the fusion machinery and for engineering next-generation subunit vaccines or inhibitors against this medically important virus family.
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