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Yang C, Liu J, Khoo RSH, Abdelsamie M, Qi M, Li H, Mao H, Hemenway S, Xu Q, Wang Y, Yu B, Zhang Q, Liu X, Klivansky LM, Gu X, Zhu C, Reimer JA, Cui G, Sutter-Fella CM, Zhang J, Ren G, Liu Y. High-fidelity topochemical polymerization in single crystals, polycrystals, and solution aggregates. Nat Commun 2025; 16:3498. [PMID: 40221394 PMCID: PMC11993752 DOI: 10.1038/s41467-025-58822-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2024] [Accepted: 04/03/2025] [Indexed: 04/14/2025] Open
Abstract
Topochemical polymerization (TCP) emerges as a leading approach for synthesizing single crystalline polymers, but is traditionally restricted to transformations in solid-medium. The complexity in achieving single-crystal-to-single-crystal (SCSC) transformations due to lattice disparities and the untapped potential of performing TCP in a liquid medium with solid-state structural fidelity present unsolved challenges. Herein, by using X-rays as the primary means to overcome crystal disintegration, we reveal the details of SCSC transformation during the TCP of chiral azaquinodimethane (AQM) monomers through in situ crystallographic analysis while spotlighting a rare metastable crystalline phase. Complementary in situ investigations of powders and thin films provide critical insights into the side-chain dependent polymerization kinetics of solid-state reactions. Furthermore, we enable TCP of AQM monomers in a liquid medium via an antisolvent-reinforced aggregated state, yielding polymer nanofibers with high crystallinity akin to that of solid-state. This study testifies high structural precision of TCP performed in different states and media, offering critical insights into the synthesis of processable nanostructured polymers with desired structural integrity.
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Affiliation(s)
- Chongqing Yang
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Rebecca Shu Hui Khoo
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Maged Abdelsamie
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Interdisciplinary Research Center for Intelligent Manufacturing and Robotics, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, 31261, Saudi Arabia
| | - Miao Qi
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - He Li
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Haiyan Mao
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
| | - Sydney Hemenway
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Qiang Xu
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yunfei Wang
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- School of Polymer Science and Engineering Center for Optoelectronic Materials and Devices, The University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Beihang Yu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Qingsong Zhang
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Xinxin Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University, Beijing, 100875, P.R. China
| | - Liana M Klivansky
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Xiaodan Gu
- School of Polymer Science and Engineering Center for Optoelectronic Materials and Devices, The University of Southern Mississippi, Hattiesburg, MS, 39406, USA
| | - Chenhui Zhu
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jeffrey A Reimer
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA, 94720, USA
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University, Beijing, 100875, P.R. China
| | | | - Jian Zhang
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Yi Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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2
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Sottatipreedawong M, Kazmi AA, Vercellino I. How Cryo-EM Revolutionized the Field of Bioenergetics. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2025; 31:ozae089. [PMID: 39298136 DOI: 10.1093/mam/ozae089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/11/2024] [Accepted: 08/31/2024] [Indexed: 02/19/2025]
Abstract
Ten years ago, the term "resolution revolution" was used for the first time to describe how cryogenic electron microscopy (cryo-EM) marked the beginning of a new era in the field of structural biology, enabling the investigation of previously unsolvable protein targets. The success of cryo-EM was recognized with the 2017 Chemistry Nobel Prize and has become a widely used method for the structural characterization of biological macromolecules, quickly catching up to x-ray crystallography. Bioenergetics is the division of biochemistry that studies the mechanisms of energy conversion in living organisms, strongly focused on the molecular machines (enzymes) that carry out these processes in cells. As bioenergetic enzymes can be arranged in complexes characterized by conformational heterogeneity/flexibility, they represent challenging targets for structural investigation by crystallography. Over the last decade, cryo-EM has therefore become a powerful tool to investigate the structure and function of bioenergetic complexes; here, we provide an overview of the main achievements enabled by the technique. We first summarize the features of cryo-EM and compare them to x-ray crystallography, and then, we present the exciting discoveries brought about by cryo-EM, particularly but not exclusively focusing on the oxidative phosphorylation system, which is a crucial energy-converting mechanism in humans.
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Affiliation(s)
- Muratha Sottatipreedawong
- Ernst RuskaCentre 3 for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße 52428 Jülich (DE)
| | - Ahad Ali Kazmi
- Ernst RuskaCentre 3 for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße 52428 Jülich (DE)
| | - Irene Vercellino
- Ernst RuskaCentre 3 for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße 52428 Jülich (DE)
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3
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Lee S, Kibler RD, Ahn G, Hsia Y, Borst AJ, Philomin A, Kennedy MA, Huang B, Stoddard B, Baker D. Four-component protein nanocages designed by programmed symmetry breaking. Nature 2025; 638:546-552. [PMID: 39695226 PMCID: PMC11821509 DOI: 10.1038/s41586-024-07814-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 07/11/2024] [Indexed: 12/20/2024]
Abstract
Four, eight or twenty C3 symmetric protein trimers can be arranged with tetrahedral, octahedral or icosahedral point group symmetry to generate closed cage-like structures1,2. Viruses access more complex higher triangulation number icosahedral architectures by breaking perfect point group symmetry3-9, but nature appears not to have explored similar symmetry breaking for tetrahedral or octahedral symmetries. Here we describe a general design strategy for building higher triangulation number architectures starting from regular polyhedra through pseudosymmetrization of trimeric building blocks. Electron microscopy confirms the structures of T = 4 cages with 48 (tetrahedral), 96 (octahedral) and 240 (icosahedral) subunits, each with 4 distinct chains and 6 different protein-protein interfaces, and diameters of 33 nm, 43 nm and 75 nm, respectively. Higher triangulation number viruses possess very sophisticated functionalities; our general route to higher triangulation number nanocages should similarly enable a next generation of multiple antigen-displaying vaccine candidates10,11 and targeted delivery vehicles12,13.
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Affiliation(s)
- Sangmin Lee
- 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
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Ryan D Kibler
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Green Ahn
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Yang Hsia
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Andrew J Borst
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Annika Philomin
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Madison A Kennedy
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Buwei Huang
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Barry Stoddard
- Division of Basic Sciences, Fred Hutchinson Cancer Center, 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.
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4
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Adams CS, Kim H, Burtner AE, Lee DS, Dobbins C, Criswell C, Coventry B, Tran-Pearson A, Kim HM, King NP. De novo design of protein minibinder agonists of TLR3. Nat Commun 2025; 16:1234. [PMID: 39890776 PMCID: PMC11785957 DOI: 10.1038/s41467-025-56369-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: 04/18/2024] [Accepted: 01/16/2025] [Indexed: 02/03/2025] Open
Abstract
Toll-like Receptor 3 (TLR3) is a pattern recognition receptor that initiates antiviral immune responses upon binding double-stranded RNA (dsRNA). Several nucleic acid-based TLR3 agonists have been explored clinically as vaccine adjuvants in cancer and infectious disease, but present substantial manufacturing and formulation challenges. Here, we use computational protein design to create novel miniproteins that bind to human TLR3 with nanomolar affinities. Cryo-EM structures of two minibinders in complex with TLR3 reveal that they bind the target as designed, although one partially unfolds due to steric competition with a nearby N-linked glycan. Multivalent forms of both minibinders induce NF-κB signaling in TLR3-expressing cell lines, demonstrating that they may have therapeutically relevant biological activity. Our work provides a foundation for the development of specific, stable, and easy-to-formulate protein-based agonists of TLRs and other pattern recognition receptors.
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Affiliation(s)
- Chloe S Adams
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Hyojin Kim
- Center for Biomolecular & Cellular Structure, Institute for Basic Science (IBS), Daejeon, 34126, South Korea
| | - Abigail E Burtner
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Dong Sun Lee
- Center for Biomolecular & Cellular Structure, Institute for Basic Science (IBS), Daejeon, 34126, South Korea
| | - Craig Dobbins
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Cameron Criswell
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Brian Coventry
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA, USA
| | - Adri Tran-Pearson
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA
| | - Ho Min Kim
- Center for Biomolecular & Cellular Structure, Institute for Basic Science (IBS), Daejeon, 34126, South Korea.
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea.
| | - Neil P King
- Institute for Protein Design, University of Washington, Seattle, WA, 98195, USA.
- Department of Biochemistry, University of Washington, Seattle, WA, 98195, USA.
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5
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Venugopal H, Mobbs J, Taveneau C, Fox DR, Vuckovic Z, Gulati S, Knott G, Grinter R, Thal D, Mick S, Czarnik C, Ramm G. High-resolution cryo-EM using a common LaB 6 120-keV electron microscope equipped with a sub-200-keV direct electron detector. SCIENCE ADVANCES 2025; 11:eadr0438. [PMID: 39752481 PMCID: PMC11698077 DOI: 10.1126/sciadv.adr0438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Accepted: 11/27/2024] [Indexed: 01/06/2025]
Abstract
High-resolution cryo-electron microscopy (cryo-EM) requires costly 200- to 300-keV cryo-transmission electron microscopes (cryo-TEMs) with field emission gun (FEG) sources, stable columns, constant-powered lenses, autoloader, and direct electron detectors (DED). Recent advances in 100-keV imaging with the emergence of sub-200-keV optimized DED technology promises the development of more affordable cryo-TEMs. So far, 100-keV imaging has required microscopes with FEG sources. We here explored whether a standard 120-keV TEMs with thermionic lanthanum hexaboride (LaB6) source can be upgraded with a sub-200-keV DED for high-resolution cryo-EM. Using this imaging configuration, we successfully obtained a 2.65 Å reconstruction for apoferritin, 4.33 Å for 64-kDa hemoglobin, and 4.4 Å for an asymmetric 153kDa membrane protein GPCR. All results were achieved using standard automated data collection with SerialEM, demonstrating the feasibility to collect large cryo-EM datasets with a side-entry cryo-holder. These results showcase a widely accessible solution to obtaining interpretable cryo-EM structures at low cost and contribute to the "democratization" of cryo-EM.
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Affiliation(s)
- Hariprasad Venugopal
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, VIC, Australia
| | - Jesse Mobbs
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Cyntia Taveneau
- GlycoEra AG, Einsiedlerstrasse 34, 8820 Wädenswil, Switzerland
| | - Daniel R. Fox
- Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Ziva Vuckovic
- GlycoEra AG, Einsiedlerstrasse 34, 8820 Wädenswil, Switzerland
| | | | - Gavin Knott
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Rhys Grinter
- Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia
- Department of Biochemistry and Pharmacology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - David Thal
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Australian Research Council Centre for Cryo-Electron Microscopy of Membrane Proteins, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | | | | | - Georg Ramm
- Ramaciotti Centre for Cryo-Electron Microscopy, Monash University, Clayton, VIC, Australia
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
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6
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Kreutzberger MAB, Sonani RR, Egelman EH. Cryo-EM reconstruction of helical polymers: Beyond the simple cases. Q Rev Biophys 2024; 57:e16. [PMID: 39658802 PMCID: PMC11730170 DOI: 10.1017/s0033583524000155] [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] [Indexed: 12/12/2024]
Abstract
Helices are one of the most frequently encountered symmetries in biological assemblies. Helical symmetry has been exploited in electron microscopic studies as a limited number of filament images, in principle, can provide all the information needed to do a three-dimensional reconstruction of a polymer. Over the past 25 years, three-dimensional reconstructions of helical polymers from cryo-EM images have shifted completely from Fourier-Bessel methods to single-particle approaches. The single-particle approaches have allowed people to surmount the problem that very few biological polymers are crystalline in order, and despite the flexibility and heterogeneity present in most of these polymers, reaching a resolution where accurate atomic models can be built has now become the standard. While determining the correct helical symmetry may be very simple for something like F-actin, for many other polymers, particularly those formed from small peptides, it can be much more challenging. This review discusses why symmetry determination can be problematic, and why trial-and-error methods are still the best approach. Studies of many macromolecular assemblies, such as icosahedral capsids, have usually found that not imposing symmetry leads to a great reduction in resolution while at the same time revealing possibly interesting asymmetric features. We show that for certain helical assemblies asymmetric reconstructions can sometimes lead to greatly improved resolution. Further, in the case of supercoiled flagellar filaments from bacteria and archaea, we show that the imposition of helical symmetry can not only be wrong, but is not necessary, and obscures the mechanisms whereby these filaments supercoil.
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Affiliation(s)
- Mark A B Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia Medical School, Charlottesville, VA, USA
| | - Ravi R Sonani
- Department of Biochemistry and Molecular Genetics, University of Virginia Medical School, Charlottesville, VA, USA
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia Medical School, Charlottesville, VA, USA
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7
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Bobe D, Kopylov M, Miller J, Owji AP, Eng ET. Multi-species cryoEM calibration and workflow verification standard. Acta Crystallogr F Struct Biol Commun 2024; 80:320-327. [PMID: 39494502 PMCID: PMC11533365 DOI: 10.1107/s2053230x24010318] [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: 08/06/2024] [Accepted: 10/23/2024] [Indexed: 11/05/2024] Open
Abstract
Cryogenic electron microscopy (cryoEM) is a rapidly growing structural biology modality that has been successful in revealing molecular details of biological systems. However, unlike established biophysical and analytical techniques with calibration standards, cryoEM has lacked comprehensive biological test samples. Here, a cryoEM calibration sample consisting of a mixture of compatible macromolecules is introduced that can not only be used for resolution optimization, but also provides multiple reference points for evaluating instrument performance, data quality and image-processing workflows in a single experiment. This combined test specimen provides researchers with a reference point for validating their cryoEM pipeline, benchmarking their methodologies and testing new algorithms.
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Affiliation(s)
- Daija Bobe
- Simons Electron Microscopy CenterNew York Structural Biology CenterNew YorkNew YorkUSA
| | - Mykhailo Kopylov
- Simons Electron Microscopy CenterNew York Structural Biology CenterNew YorkNew YorkUSA
| | - Jessalyn Miller
- Simons Electron Microscopy CenterNew York Structural Biology CenterNew YorkNew YorkUSA
| | - Aaron P. Owji
- Simons Electron Microscopy CenterNew York Structural Biology CenterNew YorkNew YorkUSA
| | - Edward T. Eng
- Simons Electron Microscopy CenterNew York Structural Biology CenterNew YorkNew YorkUSA
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8
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Liu J, McRae EKS, Zhang M, Geary C, Andersen ES, Ren G. Non-averaged single-molecule tertiary structures reveal RNA self-folding through individual-particle cryo-electron tomography. Nat Commun 2024; 15:9084. [PMID: 39433544 PMCID: PMC11494099 DOI: 10.1038/s41467-024-52914-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 09/23/2024] [Indexed: 10/23/2024] Open
Abstract
Large-scale and continuous conformational changes in the RNA self-folding process present significant challenges for structural studies, often requiring trade-offs between resolution and observational scope. Here, we utilize individual-particle cryo-electron tomography (IPET) to examine the post-transcriptional self-folding process of designed RNA origami 6-helix bundle with a clasp helix (6HBC). By avoiding selection, classification, averaging, or chemical fixation and optimizing cryo-ET data acquisition parameters, we reconstruct 120 three-dimensional (3D) density maps from 120 individual particles at an electron dose of no more than 168 e-Å-2, achieving averaged resolutions ranging from 23 to 35 Å, as estimated by Fourier shell correlation (FSC) at 0.5. Each map allows us to identify distinct RNA helices and determine a unique tertiary structure. Statistical analysis of these 120 structures confirms two reported conformations and reveals a range of kinetically trapped, intermediate, and highly compacted states, demonstrating a maturation folding landscape likely driven by helix-helix compaction interactions.
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Affiliation(s)
- Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Ewan K S McRae
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000, Aarhus, Denmark
- Center for RNA Therapeutics, Houston Methodist Research Institute, Houston, TX, 77030, USA
| | - Meng Zhang
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
| | - Cody Geary
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000, Aarhus, Denmark
- Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg University, 69120, Heidelberg, Germany
| | - Ebbe Sloth Andersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, DK-8000, Aarhus, Denmark.
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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9
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Fan S, Liu J, Chofflet N, Bailey AO, Russell WK, Zhang Z, Takahashi H, Ren G, Rudenko G. Molecular mechanism of contactin 2 homophilic interaction. Structure 2024; 32:1652-1666.e8. [PMID: 38968938 PMCID: PMC11455609 DOI: 10.1016/j.str.2024.06.004] [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: 04/12/2024] [Revised: 05/23/2024] [Accepted: 06/10/2024] [Indexed: 07/07/2024]
Abstract
Contactin 2 (CNTN2) is a cell adhesion molecule involved in axon guidance, neuronal migration, and fasciculation. The ectodomains of CNTN1-CNTN6 are composed of six Ig domains (Ig1-Ig6) and four FN domains. Here, we show that CNTN2 forms transient homophilic interactions (KD ∼200 nM). Cryo-EM structures of full-length CNTN2 and CNTN2_Ig1-Ig6 reveal a T-shaped homodimer formed by intertwined, parallel monomers. Unexpectedly, the horseshoe-shaped Ig1-Ig4 headpieces extend their Ig2-Ig3 tips outwards on either side of the homodimer, while Ig4, Ig5, Ig6, and the FN domains form a central stalk. Cross-linking mass spectrometry and cell-based binding assays confirm the 3D assembly of the CNTN2 homodimer. The interface mediating homodimer formation differs between CNTNs, as do the homophilic versus heterophilic interaction mechanisms. The CNTN family thus encodes a versatile molecular platform that supports a very diverse portfolio of protein interactions and that can be leveraged to strategically guide neural circuit development.
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Affiliation(s)
- Shanghua Fan
- Department of Pharmacology and Toxicology; University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Nicolas Chofflet
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B2, Canada
| | - Aaron O Bailey
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - William K Russell
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Ziqi Zhang
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
| | - Hideto Takahashi
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada; Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada; Division of Experimental Medicine, McGill University, Montreal, QC H3A 0G4, Canada.
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Gabby Rudenko
- Department of Pharmacology and Toxicology; University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA.
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10
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Zhang X, Li S, Zhang K. Cryo-EM: A window into the dynamic world of RNA molecules. Curr Opin Struct Biol 2024; 88:102916. [PMID: 39232250 DOI: 10.1016/j.sbi.2024.102916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 08/10/2024] [Accepted: 08/10/2024] [Indexed: 09/06/2024]
Abstract
RNAs are critical for complex cellular functions, characterized by their structural versatility and ability to undergo conformational transitions in response to cellular cues. The elusive structures of RNAs are being unraveled with unprecedented clarity, thanks to the technological advancements in structural biology, including nuclear magnetic resonance (NMR), X-ray crystallography, cryo-electron microscopy (cryo-EM) etc. This review focuses on examining the revolutionary impact of cryo-EM on our comprehension of RNA structural dynamics, underscoring the technique's contributions to structural biology and envisioning the future trajectory of this rapidly evolving field.
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Affiliation(s)
- Xiaojing Zhang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Shanshan Li
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Kaiming Zhang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.
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11
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Chan LM, Courteau BJ, Maker A, Wu M, Basanta B, Mehmood H, Bulkley D, Joyce D, Lee BC, Mick S, Czarnik C, Gulati S, Lander GC, Verba KA. High-resolution single-particle imaging at 100-200 keV with the Gatan Alpine direct electron detector. J Struct Biol 2024; 216:108108. [PMID: 38944401 PMCID: PMC11542591 DOI: 10.1016/j.jsb.2024.108108] [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: 02/14/2024] [Revised: 06/03/2024] [Accepted: 06/26/2024] [Indexed: 07/01/2024]
Abstract
Developments in direct electron detector technology have played a pivotal role in enabling high-resolution structural studies by cryo-EM at 200 and 300 keV. Yet, theory and recent experiments indicate advantages to imaging at 100 keV, energies for which the current detectors have not been optimized. In this study, we evaluated the Gatan Alpine detector, designed for operation at 100 and 200 keV. Compared to the Gatan K3, Alpine demonstrated a significant DQE improvement at these energies, specifically a ∼ 4-fold improvement at Nyquist at 100 keV. In single-particle cryo-EM experiments, Alpine datasets yielded better than 2 Å resolution reconstructions of apoferritin at 120 and 200 keV on a ThermoFisher Scientific (TFS) Glacios microscope fitted with a non-standard SP-Twin lens. We also achieved a ∼ 3.2 Å resolution reconstruction of a 115 kDa asymmetric protein complex, proving Alpine's effectiveness with complex biological samples. In-depth analysis revealed that Alpine reconstructions are comparable to K3 reconstructions at 200 keV, and remarkably, reconstruction from Alpine at 120 keV on a TFS Glacios surpassed all but the 300 keV data from a TFS Titan Krios with GIF/K3. Additionally, we show Alpine's capability for high-resolution data acquisition and screening on lower-end systems by obtaining ∼ 3 Å resolution reconstructions of apoferritin and aldolase at 100 keV and detailed 2D averages of a 55 kDa sample using a side-entry cryo holder. Overall, we show that Gatan Alpine performs well with the standard 200 keV imaging systems and may potentially capture the benefits of lower accelerating voltages, bringing smaller sized particles within the scope of cryo-EM.
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Affiliation(s)
- Lieza M Chan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - Brandon J Courteau
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - Allison Maker
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - Mengyu Wu
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92024, United States
| | - Benjamin Basanta
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92024, United States
| | - Hev Mehmood
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - David Bulkley
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA 94158, United States
| | | | | | | | | | | | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92024, United States.
| | - Kliment A Verba
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States.
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12
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Bobe D, Kopylov M, Miller J, Owji AP, Eng ET. Multi-species cryoEM calibration and workflow verification standard. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.05.606612. [PMID: 39149318 PMCID: PMC11326162 DOI: 10.1101/2024.08.05.606612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Cryogenic electron microscopy (cryoEM) is a rapidly growing structural biology modality that has been successful in revealing molecular details of biological systems. However, unlike established biophysical and analytical techniques with calibration standards, cryoEM has lacked comprehensive biological test samples. We introduce a cryoEM calibration sample that is a mixture of compatible macromolecules that can be used not only for resolution optimization but also provides multiple reference points for evaluating instrument performance, data quality, and image processing workflows in a single experiment. This combined test specimen provides researchers a reference point for validating their cryoEM pipeline, benchmarking their methodologies, and testing new algorithms.
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Affiliation(s)
- Daija Bobe
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Mykhailo Kopylov
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Jessalyn Miller
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Aaron P. Owji
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
| | - Edward T. Eng
- Simons Electron Microscopy Center, New York Structural Biology Center, New York, NY 10027, USA
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13
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Pillai A, Idris A, Philomin A, Weidle C, Skotheim R, Leung PJY, Broerman A, Demakis C, Borst AJ, Praetorius F, Baker D. De novo design of allosterically switchable protein assemblies. Nature 2024; 632:911-920. [PMID: 39143214 PMCID: PMC11338832 DOI: 10.1038/s41586-024-07813-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 07/11/2024] [Indexed: 08/16/2024]
Abstract
Allosteric modulation of protein function, wherein the binding of an effector to a protein triggers conformational changes at distant functional sites, plays a central part in the control of metabolism and cell signalling1-3. There has been considerable interest in designing allosteric systems, both to gain insight into the mechanisms underlying such 'action at a distance' modulation and to create synthetic proteins whose functions can be regulated by effectors4-7. However, emulating the subtle conformational changes distributed across many residues, characteristic of natural allosteric proteins, is a significant challenge8,9. Here, inspired by the classic Monod-Wyman-Changeux model of cooperativity10, we investigate the de novo design of allostery through rigid-body coupling of peptide-switchable hinge modules11 to protein interfaces12 that direct the formation of alternative oligomeric states. We find that this approach can be used to generate a wide variety of allosterically switchable systems, including cyclic rings that incorporate or eject subunits in response to peptide binding and dihedral cages that undergo effector-induced disassembly. Size-exclusion chromatography, mass photometry13 and electron microscopy reveal that these designed allosteric protein assemblies closely resemble the design models in both the presence and absence of peptide effectors and can have ligand-binding cooperativity comparable to classic natural systems such as haemoglobin14. Our results indicate that allostery can arise from global coupling of the energetics of protein substructures without optimized side-chain-side-chain allosteric communication pathways and provide a roadmap for generating allosterically triggerable delivery systems, protein nanomachines and cellular feedback control circuitry.
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Affiliation(s)
- Arvind Pillai
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
| | - Abbas Idris
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Annika Philomin
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Connor Weidle
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Rebecca Skotheim
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Philip J Y Leung
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Program in Molecular Engineering, University of Washington, Seattle, WA, USA
| | - Adam Broerman
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA
| | - Cullen Demakis
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Graduate Program in Biological Physics, Structure, and Design, University of Washington, Seattle, WA, USA
| | - Andrew J Borst
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Florian Praetorius
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria.
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
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14
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Kang H, Han AR, Zhang A, Jeong H, Koh W, Lee JM, Lee H, Jo HY, Maria-Solano MA, Bhalla M, Kwon J, Roh WS, Yang J, An HJ, Choi S, Kim HM, Lee CJ. GolpHCat (TMEM87A), a unique voltage-dependent cation channel in Golgi apparatus, contributes to Golgi-pH maintenance and hippocampus-dependent memory. Nat Commun 2024; 15:5830. [PMID: 38992057 PMCID: PMC11239671 DOI: 10.1038/s41467-024-49297-8] [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: 12/14/2023] [Accepted: 05/30/2024] [Indexed: 07/13/2024] Open
Abstract
Impaired ion channels regulating Golgi pH lead to structural alterations in the Golgi apparatus, such as fragmentation, which is found, along with cognitive impairment, in Alzheimer's disease. However, the causal relationship between altered Golgi structure and cognitive impairment remains elusive due to the lack of understanding of ion channels in the Golgi apparatus of brain cells. Here, we identify that a transmembrane protein TMEM87A, renamed Golgi-pH-regulating cation channel (GolpHCat), expressed in astrocytes and neurons that contributes to hippocampus-dependent memory. We find that GolpHCat displays unique voltage-dependent currents, which is potently inhibited by gluconate. Additionally, we gain structural insights into the ion conduction through GolpHCat at the molecular level by determining three high-resolution cryogenic-electron microscopy structures of human GolpHCat. GolpHCat-knockout mice show fragmented Golgi morphology and altered protein glycosylation and functions in the hippocampus, leading to impaired spatial memory. These findings suggest a molecular target for Golgi-related diseases and cognitive impairment.
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Affiliation(s)
- Hyunji Kang
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
- IBS School, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea
| | - Ah-Reum Han
- Center for Biomolecular and Cellular Structure, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Aihua Zhang
- Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Heejin Jeong
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Korea
| | - Wuhyun Koh
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Jung Moo Lee
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Hayeon Lee
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Hee Young Jo
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Korea
| | - Miguel A Maria-Solano
- Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Seoul, 03760, Republic of Korea
| | - Mridula Bhalla
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Jea Kwon
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Woo Suk Roh
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Jimin Yang
- Center for Biomolecular and Cellular Structure, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea
| | - Hyun Joo An
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Korea
| | - Sun Choi
- Global AI Drug Discovery Center, College of Pharmacy and Graduate School of Pharmaceutical Science, Ewha Womans University, Seoul, 03760, Republic of Korea.
| | - Ho Min Kim
- Center for Biomolecular and Cellular Structure, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea.
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
| | - C Justin Lee
- Center for Cognition and Sociality, Life Science Cluster, Institute for Basic Science (IBS), 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Republic of Korea.
- IBS School, University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon, 34113, Republic of Korea.
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15
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Morgenstern TJ, Darko-Boateng A, Afriyie E, Shanmugam SK, Zhou X, Choudhury P, Desai M, Kass RS, Clarke OB, Colecraft HM. Ion channel inhibition by targeted recruitment of NEDD4-2 with divalent nanobodies. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596281. [PMID: 38854018 PMCID: PMC11160594 DOI: 10.1101/2024.05.28.596281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Targeted recruitment of E3 ubiquitin ligases to degrade traditionally undruggable proteins is a disruptive paradigm for developing new therapeutics. Two salient limitations are that <2% of the ~600 E3 ligases in the human genome have been exploited to produce proteolysis targeting chimeras (PROTACs), and the efficacy of the approach has not been demonstrated for a vital class of complex multi-subunit membrane proteins- ion channels. NEDD4-1 and NEDD4-2 are physiological regulators of myriad ion channels, and belong to the 28-member HECT (homologous to E6AP C-terminus) family of E3 ligases with widespread roles in cell/developmental biology and diverse diseases including various cancers, immunological and neurological disorders, and chronic pain. The potential efficacy of HECT E3 ligases for targeted protein degradation is unexplored, constrained by a lack of appropriate binders, and uncertain due to their complex regulation by layered intra-molecular and posttranslational mechanisms. Here, we identified a nanobody that binds with high affinity and specificity to a unique site on the N-lobe of the NEDD4-2 HECT domain at a location physically separate from sites critical for catalysis- the E2 binding site, the catalytic cysteine, and the ubiquitin exosite- as revealed by a 3.1 Å cryo-electron microscopy reconstruction. Recruiting endogenous NEDD4-2 to diverse ion channel proteins (KCNQ1, ENaC, and CaV2.2) using a divalent (DiVa) nanobody format strongly reduced their functional expression with minimal off-target effects as assessed by global proteomics, compared to simple NEDD4-2 overexpression. The results establish utility of a HECT E3 ligase for targeted protein downregulation, validate a class of complex multi-subunit membrane proteins as susceptible to this modality, and introduce endogenous E3 ligase recruitment with DiVa nanobodies as a general method to generate novel genetically-encoded ion channel inhibitors.
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Affiliation(s)
- Travis J. Morgenstern
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY
| | - Arden Darko-Boateng
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY
| | - Emmanuel Afriyie
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY
| | - Sri Karthika Shanmugam
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY
| | - Xinle Zhou
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY
| | - Papiya Choudhury
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY
| | | | - Robert S. Kass
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY
| | - Oliver B. Clarke
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY
- Department of Anesthesiology, Columbia University Irving Medical Center, New York, NY
| | - Henry M. Colecraft
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, NY
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY
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16
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Premageetha GT, Vinothkumar KR, Bose S. Exploring advances in single particle CryoEM with apoferritin: From blobs to true atomic resolution. Int J Biochem Cell Biol 2024; 169:106536. [PMID: 38307321 DOI: 10.1016/j.biocel.2024.106536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 01/21/2024] [Accepted: 01/23/2024] [Indexed: 02/04/2024]
Abstract
Deciphering the three-dimensional structures of macromolecules is of paramount importance for gaining insights into their functions and roles in human health and disease. Single particle cryoEM has emerged as a powerful technique that enables direct visualization of macromolecules and their complexes, and through subsequent averaging, achieve near atomic-level resolution. A major breakthrough was recently achieved with the determination of the apoferritin structure at true atomic resolution. In this review, we discuss the latest technological innovations across the entire single-particle workflow, which have been instrumental in driving the resolution revolution and in transforming cryoEM as a mainstream technique in structural biology. We illustrate these advancements using apoferritin as an example that has served as an excellent benchmark sample for assessing emerging technologies. We further explore whether the existing technology can routinely generate atomic structures of dynamic macromolecules that more accurately represent real-world samples, the limitations in the workflow, and the current approaches employed to overcome them.
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Affiliation(s)
- Gowtham ThambraRajan Premageetha
- Institute for Stem Cell Science and Regenerative Medicine, GKVK Post, Bangalore 560065, India; Manipal Academy of Higher Education, Tiger Circle Road, Manipal, Karnataka 576104, India.
| | - Kutti R Vinothkumar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Post, Bangalore 560065, India
| | - Sucharita Bose
- Institute for Stem Cell Science and Regenerative Medicine, GKVK Post, Bangalore 560065, India.
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17
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Chan LM, Courteau BJ, Maker A, Wu M, Basanta B, Mehmood H, Bulkley D, Joyce D, Lee BC, Mick S, Gulati S, Lander GC, Verba KA. High-resolution single-particle imaging at 100-200 keV with the Gatan Alpine direct electron detector. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.14.580363. [PMID: 38405886 PMCID: PMC10888765 DOI: 10.1101/2024.02.14.580363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Developments in direct electron detector technology have played a pivotal role in enabling high-resolution structural studies by cryo-EM at 200 and 300 keV. Yet, theory and recent experiments indicate advantages to imaging at 100 keV, energies for which the current detectors have not been optimized. In this study, we evaluated the Gatan Alpine detector, designed for operation at 100 and 200 keV. Compared to the Gatan K3, Alpine demonstrated a significant DQE improvement at these voltages, specifically a ~4-fold improvement at Nyquist at 100 keV. In single-particle cryo-EM experiments, Alpine datasets yielded better than 2 Å resolution reconstructions of apoferritin at 120 and 200 keV on a ThermoFisher Scientific (TFS) Glacios microscope. We also achieved a ~3.2 Å resolution reconstruction for a 115 kDa asymmetric protein complex, proving its effectiveness with complex biological samples. In-depth analysis revealed that Alpine reconstructions are comparable to K3 reconstructions at 200 keV, and remarkably, reconstruction from Alpine at 120 keV on a TFS Glacios surpassed all but the 300 keV data from a TFS Titan Krios with GIF/K3. Additionally, we show Alpine's capability for high-resolution data acquisition and screening on lower-end systems by obtaining ~3 Å resolution reconstructions of apoferritin and aldolase at 100 keV and detailed 2D averages of a 55 kDa sample using a side-entry cryo holder. Overall, we show that Gatan Alpine performs well with the standard 200 keV imaging systems and may potentially capture the benefits of lower accelerating voltages, possibly bringing smaller sized particles within the scope of cryo-EM.
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Affiliation(s)
- Lieza M Chan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - Brandon J Courteau
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - Allison Maker
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - Mengyu Wu
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92024, United States
| | - Benjamin Basanta
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92024, United States
| | - Hevatib Mehmood
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
| | - David Bulkley
- Department of Biochemistry & Biophysics, University of California, San Francisco, CA 94158, United States
| | | | | | | | | | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, CA 92024, United States
| | - Kliment A Verba
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, United States
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18
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Wei J, Moore K, Bammes B, Levin BDA, Hagopian N, Jacobs R, Morgan D, Voyles PM. Deep Learning Approach for High-accuracy Electron Counting of Monolithic Active Pixel Sensor-type Direct Electron Detectors at Increased Electron Dose. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:2026-2036. [PMID: 38066670 DOI: 10.1093/micmic/ozad132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/25/2023] [Accepted: 11/05/2023] [Indexed: 12/23/2023]
Abstract
Electron counting can be performed algorithmically for monolithic active pixel sensor direct electron detectors to eliminate readout noise and Landau noise arising from the variability in the amount of deposited energy for each electron. Errors in existing counting algorithms include mistakenly counting a multielectron strike as a single electron event, and inaccurately locating the incident position of the electron due to lateral spread of deposited energy and dark noise. Here, we report a supervised deep learning (DL) approach based on Faster region-based convolutional neural network (R-CNN) to recognize single electron events at varying electron doses and voltages. The DL approach shows high accuracy according to the near-ideal modulation transfer function (MTF) and detector quantum efficiency for sparse images. It predicts, on average, 0.47 pixel deviation from the incident positions for 200 kV electrons versus 0.59 pixel using the conventional counting method. The DL approach also shows better robustness against coincidence loss as the electron dose increases, maintaining the MTF at half Nyquist frequency above 0.83 as the electron density increases to 0.06 e-/pixel. Thus, the DL model extends the advantages of counting analysis to higher dose rates than conventional methods.
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Affiliation(s)
- Jingrui Wei
- Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Ave, Madison, WI 53706, USA
| | - Kalani Moore
- Direct Electron L.P., 13240 Evening Crk S Dr Ste. 311, San Diego, CA 92128, USA
| | - Benjamin Bammes
- Direct Electron L.P., 13240 Evening Crk S Dr Ste. 311, San Diego, CA 92128, USA
| | - Barnaby D A Levin
- Direct Electron L.P., 13240 Evening Crk S Dr Ste. 311, San Diego, CA 92128, USA
| | - Nicholas Hagopian
- Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Ave, Madison, WI 53706, USA
| | - Ryan Jacobs
- Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Ave, Madison, WI 53706, USA
| | - Dane Morgan
- Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Ave, Madison, WI 53706, USA
| | - Paul M Voyles
- Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Ave, Madison, WI 53706, USA
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19
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Li Z, Wang S, Nattermann U, Bera AK, Borst AJ, Yaman MY, Bick MJ, Yang EC, Sheffler W, Lee B, Seifert S, Hura GL, Nguyen H, Kang A, Dalal R, Lubner JM, Hsia Y, Haddox H, Courbet A, Dowling Q, Miranda M, Favor A, Etemadi A, Edman NI, Yang W, Weidle C, Sankaran B, Negahdari B, Ross MB, Ginger DS, Baker D. Accurate computational design of three-dimensional protein crystals. NATURE MATERIALS 2023; 22:1556-1563. [PMID: 37845322 DOI: 10.1038/s41563-023-01683-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 09/07/2023] [Indexed: 10/18/2023]
Abstract
Protein crystallization plays a central role in structural biology. Despite this, the process of crystallization remains poorly understood and highly empirical, with crystal contacts, lattice packing arrangements and space group preferences being largely unpredictable. Programming protein crystallization through precisely engineered side-chain-side-chain interactions across protein-protein interfaces is an outstanding challenge. Here we develop a general computational approach for designing three-dimensional protein crystals with prespecified lattice architectures at atomic accuracy that hierarchically constrains the overall number of degrees of freedom of the system. We design three pairs of oligomers that can be individually purified, and upon mixing, spontaneously self-assemble into >100 µm three-dimensional crystals. The structures of these crystals are nearly identical to the computational design models, closely corresponding in both overall architecture and the specific protein-protein interactions. The dimensions of the crystal unit cell can be systematically redesigned while retaining the space group symmetry and overall architecture, and the crystals are extremely porous and highly stable. Our approach enables the computational design of protein crystals with high accuracy, and the designed protein crystals, which have both structural and assembly information encoded in their primary sequences, provide a powerful platform for biological materials engineering.
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Affiliation(s)
- Zhe Li
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Shunzhi Wang
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Una Nattermann
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Graduate Program in Biological Physics, Structure & Design, University of Washington, Seattle, WA, USA
| | - Asim K Bera
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Andrew J Borst
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Muammer Y Yaman
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Matthew J Bick
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Erin C Yang
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Graduate Program in Biological Physics, Structure & Design, University of Washington, Seattle, WA, USA
| | - William Sheffler
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Byeongdu Lee
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - Soenke Seifert
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA
| | - Greg L Hura
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Hannah Nguyen
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Alex Kang
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Radhika Dalal
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Joshua M Lubner
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Yang Hsia
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Hugh Haddox
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Alexis Courbet
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- HHMI, University of Washington, Seattle, WA, USA
| | - Quinton Dowling
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Marcos Miranda
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Andrew Favor
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Molecular Engineering and Sciences Institute, University of Washington, Seattle, WA, USA
| | - Ali Etemadi
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Medical Biotechnology Department, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Natasha I Edman
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Molecular and Cellular Biology Graduate Program, University of Washington, Seattle, WA, USA
- Medical Scientist Training Program, University of Washington, Seattle, WA, USA
| | - Wei Yang
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Connor Weidle
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Banumathi Sankaran
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Babak Negahdari
- Medical Biotechnology Department, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Michael B Ross
- Department of Chemistry, University of Massachusetts Lowell, Lowell, MA, USA
| | - David S Ginger
- Department of Chemistry, 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.
- HHMI, University of Washington, Seattle, WA, USA.
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20
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Mangan GL, Moldovan G, Stewart A. InFluence: An Open-Source Python Package to Model Images Captured with Direct Electron Detectors. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1380-1401. [PMID: 37488831 DOI: 10.1093/micmic/ozad064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 04/26/2023] [Accepted: 05/03/2023] [Indexed: 07/26/2023]
Abstract
The high detection efficiencies of direct electron detectors facilitate the routine collection of low fluence electron micrographs and diffraction patterns. Low dose and low fluence electron microscopy experiments are the only practical way to acquire useful data from beam sensitive pharmaceutical and biological materials. Appropriate modeling of low fluence images acquired using direct electron detectors is, therefore, paramount for quantitative analysis of the experimental images. We have developed a new open-source Python package to accurately model any single layer direct electron detector for low and high fluence imaging conditions, including a means to validate against experimental data through computation of modulation transfer function and detective quantum efficiency.
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Affiliation(s)
- Gearóid Liam Mangan
- Physics Department, Faculty of Science and Engineering, University of Limerick, Limerick V94 T9PX, Ireland
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
| | - Grigore Moldovan
- Point Electronic Gmbh, Erich-Neuss-Weg 15, Halle (Saale) D-06120, Germany
| | - Andrew Stewart
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
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21
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Wei J, Moore K, Bammes B, Levin BDA, Morgan D, Voyles PM. Deep Learning Approach for High-accuracy Electron Counting of Direct Electron Detectors at Increased Electron Dose. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:702-704. [PMID: 37613170 DOI: 10.1093/micmic/ozad067.346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Jingrui Wei
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Kalani Moore
- Direct Electron L.P., San Diego, CA, United States of America
| | - Benjamin Bammes
- Direct Electron L.P., San Diego, CA, United States of America
| | | | | | - Paul M Voyles
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, United States of America
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22
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McRae EKS, Rasmussen HØ, Liu J, Bøggild A, Nguyen MTA, Sampedro Vallina N, Boesen T, Pedersen JS, Ren G, Geary C, Andersen ES. Structure, folding and flexibility of co-transcriptional RNA origami. NATURE NANOTECHNOLOGY 2023; 18:808-817. [PMID: 36849548 PMCID: PMC10566746 DOI: 10.1038/s41565-023-01321-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
RNA origami is a method for designing RNA nanostructures that can self-assemble through co-transcriptional folding with applications in nanomedicine and synthetic biology. However, to advance the method further, an improved understanding of RNA structural properties and folding principles is required. Here we use cryogenic electron microscopy to study RNA origami sheets and bundles at sub-nanometre resolution revealing structural parameters of kissing-loop and crossover motifs, which are used to improve designs. In RNA bundle designs, we discover a kinetic folding trap that forms during folding and is only released after 10 h. Exploration of the conformational landscape of several RNA designs reveal the flexibility of helices and structural motifs. Finally, sheets and bundles are combined to construct a multidomain satellite shape, which is characterized by individual-particle cryo-electron tomography to reveal the domain flexibility. Together, the study provides a structural basis for future improvements to the design cycle of genetically encoded RNA nanodevices.
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Affiliation(s)
- Ewan K S McRae
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - Helena Østergaard Rasmussen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Andreas Bøggild
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - Michael T A Nguyen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | | | - Thomas Boesen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
- Department of Chemistry, Aarhus University, Aarhus, Denmark
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Cody Geary
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - Ebbe Sloth Andersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark.
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark.
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23
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Liu J, McRae EKS, Zhang M, Geary C, Andersen ES, Ren G. Tertiary structure of single-instant RNA molecule reveals folding landscape. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.19.541511. [PMID: 37292713 PMCID: PMC10245749 DOI: 10.1101/2023.05.19.541511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The folding of RNA and protein molecules during their synthesis is a crucial self-assembly process that nature employs to convert genetic information into the complex molecular machinery that supports life. Misfolding events are the cause of several diseases, and the folding pathway of central biomolecules, such as the ribosome, is strictly regulated by programmed maturation processes and folding chaperones. However, the dynamic folding processes are challenging to study because current structure determination methods heavily rely on averaging, and existing computational methods do not efficiently simulate non-equilibrium dynamics. Here we utilize individual-particle cryo-electron tomography (IPET) to investigate the folding landscape of a rationally designed RNA origami 6-helix bundle that undergoes slow maturation from a "young" to "mature" conformation. By optimizing the IPET imaging and electron dose conditions, we obtain 3D reconstructions of 120 individual particles at resolutions ranging from 23-35 Å, enabling us first-time to observe individual RNA helices and tertiary structures without averaging. Statistical analysis of 120 tertiary structures confirms the two main conformations and suggests a possible folding pathway driven by helix-helix compaction. Studies of the full conformational landscape reveal both trapped states, misfolded states, intermediate states, and fully compacted states. The study provides novel insight into RNA folding pathways and paves the way for future studies of the energy landscape of molecular machines and self-assembly processes.
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24
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Lutz ID, Wang S, Norn C, Courbet A, Borst AJ, Zhao YT, Dosey A, Cao L, Xu J, Leaf EM, Treichel C, Litvicov P, Li Z, Goodson AD, Rivera-Sánchez P, Bratovianu AM, Baek M, King NP, Ruohola-Baker H, Baker D. Top-down design of protein architectures with reinforcement learning. Science 2023; 380:266-273. [PMID: 37079676 DOI: 10.1126/science.adf6591] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 03/21/2023] [Indexed: 04/22/2023]
Abstract
As a result of evolutionary selection, the subunits of naturally occurring protein assemblies often fit together with substantial shape complementarity to generate architectures optimal for function in a manner not achievable by current design approaches. We describe a "top-down" reinforcement learning-based design approach that solves this problem using Monte Carlo tree search to sample protein conformers in the context of an overall architecture and specified functional constraints. Cryo-electron microscopy structures of the designed disk-shaped nanopores and ultracompact icosahedra are very close to the computational models. The icosohedra enable very-high-density display of immunogens and signaling molecules, which potentiates vaccine response and angiogenesis induction. Our approach enables the top-down design of complex protein nanomaterials with desired system properties and demonstrates the power of reinforcement learning in protein design.
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Affiliation(s)
- Isaac D Lutz
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Shunzhi Wang
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Christoffer Norn
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- BioInnovation Institute, DK2200 Copenhagen N, Denmark
| | - Alexis Courbet
- 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
| | - Andrew J Borst
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Yan Ting Zhao
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
- Oral Health Sciences, University of Washington, Seattle, WA, USA
| | - Annie Dosey
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Longxing Cao
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Jinwei Xu
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, 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, USA
| | - Catherine Treichel
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Patrisia Litvicov
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
| | - Zhe Li
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Alexander D Goodson
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | | | | | - Minkyung Baek
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Neil P King
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Hannele Ruohola-Baker
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, USA
- Oral Health Sciences, 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
- Department of Bioengineering, University of Washington, Seattle, WA, USA
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25
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Alexander JAN, Locher KP. Emerging structural insights into C-type glycosyltransferases. Curr Opin Struct Biol 2023; 79:102547. [PMID: 36827761 DOI: 10.1016/j.sbi.2023.102547] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 12/19/2022] [Accepted: 01/11/2023] [Indexed: 02/24/2023]
Abstract
Glycosyltransferases of the C superfamily (GT-Cs) are enzymes found in all domains of life. They catalyse the stepwise synthesis of oligosaccharides or the transfer of assembled glycans from lipid-linked donor substrates to acceptor proteins. The processes mediated by GT-Cs are required for C-, N- and O-linked glycosylation, all of which are essential post-translational modifications in higher-order eukaryotes. Until recently, GT-Cs were thought to share a conserved structural module of 7 transmembrane helices; however, recently determined GT-C structures revealed novel folds. Here we analyse the growing diversity of GT-C folds and discuss the emergence of two subclasses, termed GT-CA and GT-CB. Further substrate-bound structures are needed to facilitate a molecular understanding of glycan recognition and catalysis in these two subclasses.
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Affiliation(s)
| | - Kaspar P Locher
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland.
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26
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Cheng J, Liu T, You X, Zhang F, Sui SF, Wan X, Zhang X. Determining protein structures in cellular lamella at pseudo-atomic resolution by GisSPA. Nat Commun 2023; 14:1282. [PMID: 36922493 PMCID: PMC10017804 DOI: 10.1038/s41467-023-36175-y] [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: 07/14/2022] [Accepted: 01/18/2023] [Indexed: 03/17/2023] Open
Abstract
Cryo-electron tomography is a major tool used to study the structure of protein complexes in situ. However, the throughput of tilt-series image data collection is still quite low. Here, we show that GisSPA, a GPU accelerated program, can translationally and rotationally localize the target protein complex in cellular lamellae, as prepared with a focused ion beam, using single cryo-electron microscopy images without tilt-series, and reconstruct the protein complex at near-atomic resolution. GisSPA allows high-throughput data collection without the acquisition of tilt-series images and reconstruction of the tomogram, which is essential for high-resolution reconstruction of asymmetric or low-symmetry protein complexes. We demonstrate the power of GisSPA with 3.4-Å and 3.9-Å resolutions of resolving phycobilisome and tetrameric photosystem II complex structures in cellular lamellae, respectively. In this work, we present GisSPA as a practical tool that facilitates high-resolution in situ protein structure determination.
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Affiliation(s)
- Jing Cheng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Tong Liu
- High Performance Computer Research Center, Institute of Computing Technology, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xin You
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Fa Zhang
- Beijing Institute of Technology, Beijing, 100081, China
| | - Sen-Fang Sui
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Xiaohua Wan
- Beijing Institute of Technology, Beijing, 100081, China.
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
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27
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Harrison PJ, Vecerkova T, Clare DK, Quigley A. A review of the approaches used to solve sub-100 kDa membrane proteins by cryo-electron microscopy. J Struct Biol 2023; 215:107959. [PMID: 37004781 DOI: 10.1016/j.jsb.2023.107959] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/07/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
Membrane proteins (MPs) are essential components of all biological membranes, contributing to key cellular functions that include signalling, molecular transport and energy metabolism. Consequently, MPs are important biomedical targets for therapeutics discovery. Despite hardware and software developments in cryo-electron microscopy, as well as MP sample preparation, MPs smaller than 100 kDa remain difficult to study structurally. Significant investment is required to overcome low levels of naturally abundant protein, MP hydrophobicity as well as conformational and compositional instability. Here we have reviewed the sample preparation approaches that have been taken to successfully express, purify and prepare small MPs for analysis by cryo-EM (those with a total solved molecular weight of under 100 kDa), as well as examining the differing approaches towards data processing and ultimately obtaining a structural solution. We highlight common challenges at each stage in the process as well as strategies that have been developed to overcome these issues. Finally, we discuss future directions and opportunities for the study of sub-100 kDa membrane proteins by cryo-EM.
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28
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Fréchin L, Holvec S, von Loeffelholz O, Hazemann I, Klaholz BP. High-resolution cryo-EM performance comparison of two latest-generation cryo electron microscopes on the human ribosome. J Struct Biol 2023; 215:107905. [PMID: 36241135 DOI: 10.1016/j.jsb.2022.107905] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 09/23/2022] [Accepted: 10/05/2022] [Indexed: 11/29/2022]
Abstract
Recent technological advances in cryo electron microscopy (cryo-EM) have led to new opportunities in the structural biology field. Here we benchmark the performance of two 300 kV latest-generation cryo electron microscopes, Titan Krios G4 from Thermofisher Scientific and CRYO ARM 300 from Jeol, with regards to achieving high resolution single particle reconstructions on a real case sample. We compare potentially limiting factors such as drift rates, astigmatism & coma aberrations and performance during image processing and show that both microscopes, while comprising rather different technical setups & parameter settings and equipped with different types of energy filters & cameras, achieve a resolution of around 2 Å on the human ribosome, a non-symmetric object which constitutes a key drug target. Astigmatism correction, CTF refinement and correction of higher order aberrations through refinement in separate optics groups helped to account for astigmatism/coma caused by beam tilting during multi-spot and multi-hole acquisition in neighbouring holes without stage movement. The obtained maps resolve Mg2+ ions, water molecules, inhibitors and side-chains including chemical modifications. The fact that both instruments can resolve such detailed features will greatly facilitate understanding molecular mechanisms of various targets and helps in cryo-EM structure based drug design. The methods and analysis tools used here will be useful also to characterize existing instruments and optimize data acquisition settings and are applicable broadly to other drug targets in structural biology.
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Affiliation(s)
- Léo Fréchin
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Samuel Holvec
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Ottilie von Loeffelholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Isabelle Hazemann
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France
| | - Bruno P Klaholz
- Centre for Integrative Biology (CBI), Department of Integrated Structural Biology, IGBMC (Institute of Genetics and of Molecular and Cellular Biology), 1 rue Laurent Fries, Illkirch, France; Centre National de la Recherche Scientifique (CNRS) UMR 7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale (Inserm) U964, Illkirch, France; Université de Strasbourg, Strasbourg, France.
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29
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Gerben S, Borst AJ, Hicks DR, Moczygemba I, Feldman D, Coventry B, Yang W, Bera AK, Miranda M, Kang A, Nguyen H, Baker D. Design of Diverse Asymmetric Pockets in De Novo Homo-oligomeric Proteins. Biochemistry 2023; 62:358-368. [PMID: 36627259 PMCID: PMC9850923 DOI: 10.1021/acs.biochem.2c00497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 11/28/2022] [Indexed: 01/12/2023]
Abstract
A challenge for design of protein-small-molecule recognition is that incorporation of cavities with size, shape, and composition suitable for specific recognition can considerably destabilize protein monomers. This challenge can be overcome through binding pockets formed at homo-oligomeric interfaces between folded monomers. Interfaces surrounding the central homo-oligomer symmetry axes necessarily have the same symmetry and so may not be well suited to binding asymmetric molecules. To enable general recognition of arbitrary asymmetric substrates and small molecules, we developed an approach to designing asymmetric interfaces at off-axis sites on homo-oligomers, analogous to those found in native homo-oligomeric proteins such as glutamine synthetase. We symmetrically dock curved helical repeat proteins such that they form pockets at the asymmetric interface of the oligomer with sizes ranging from several angstroms, appropriate for binding a single ion, to up to more than 20 Å across. Of the 133 proteins tested, 84 had soluble expression in E. coli, 47 had correct oligomeric states in solution, 35 had small-angle X-ray scattering (SAXS) data largely consistent with design models, and 8 had negative-stain electron microscopy (nsEM) 2D class averages showing the structures coming together as designed. Both an X-ray crystal structure and a cryogenic electron microscopy (cryoEM) structure are close to the computational design models. The nature of these proteins as homo-oligomers allows them to be readily built into higher-order structures such as nanocages, and the asymmetric pockets of these structures open rich possibilities for small-molecule binder design free from the constraints associated with monomer destabilization.
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Affiliation(s)
- Stacey
R Gerben
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Andrew J Borst
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Derrick R Hicks
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Isabelle Moczygemba
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - David Feldman
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Brian Coventry
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Wei Yang
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Asim K. Bera
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Marcos Miranda
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Alex Kang
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - Hannah Nguyen
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
| | - David Baker
- Department
of Biochemistry, University of Washington, Seattle, Washington 98195, United States
- Institute
for Protein Design, University of Washington, Seattle, Washington 98195, United States
- Howard
Hughes Medical Institute, University of
Washington, Seattle, Washington 98195, United States
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30
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Nakanishi A, Kishikawa JI, Mitsuoka K, Yokoyama K. Cryo-EM analysis of V/A-ATPase intermediates reveals the transition of the ground-state structure to steady-state structures by sequential ATP binding. J Biol Chem 2023; 299:102884. [PMID: 36626983 PMCID: PMC9971907 DOI: 10.1016/j.jbc.2023.102884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/22/2022] [Accepted: 12/27/2022] [Indexed: 01/09/2023] Open
Abstract
Vacuolar/archaeal-type ATPase (V/A-ATPase) is a rotary ATPase that shares a common rotary catalytic mechanism with FoF1 ATP synthase. Structural images of V/A-ATPase obtained by single-particle cryo-electron microscopy during ATP hydrolysis identified several intermediates, revealing the rotary mechanism under steady-state conditions. However, further characterization is needed to understand the transition from the ground state to the steady state. Here, we identified the cryo-electron microscopy structures of V/A-ATPase corresponding to short-lived initial intermediates during the activation of the ground state structure by time-resolving snapshot analysis. These intermediate structures provide insights into how the ground-state structure changes to the active, steady state through the sequential binding of ATP to its three catalytic sites. All the intermediate structures of V/A-ATPase adopt the same asymmetric structure, whereas the three catalytic dimers adopt different conformations. This is significantly different from the initial activation process of FoF1, where the overall structure of the F1 domain changes during the transition from a pseudo-symmetric to a canonical asymmetric structure (PNAS NEXUS, pgac116, 2022). In conclusion, our findings provide dynamical information that will enhance the future prospects for studying the initial activation processes of the enzymes, which have unknown intermediate structures in their functional pathway.
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Affiliation(s)
- Atsuko Nakanishi
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto, Japan,Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, Japan
| | - Jun-ichi Kishikawa
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto, Japan,Institute for Protein Research, Osaka University, Osaka Japan
| | - Kaoru Mitsuoka
- Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, Osaka, Japan
| | - Ken Yokoyama
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto, Japan.
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31
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Hall M, Schexnaydre E, Holmlund C, Carroni M. Protein Structural Analysis by Cryogenic Electron Microscopy. Methods Mol Biol 2023; 2652:439-463. [PMID: 37093490 DOI: 10.1007/978-1-0716-3147-8_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Cryogenic electron microscopy (cryo-EM) is constantly developing and growing as a major technique for structure determination of protein complexes. Here, we detail the first steps of any cryo-EM project: specimen preparation and data collection. Step by step, a list of material needed is provided and the sequence of actions to carry out is given. We hope that these protocols will be useful to all people getting started with cryo-EM.
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Affiliation(s)
- Michael Hall
- SciLifeLab Cryo-EM Facility, Department of Chemistry, Umeå University, Umeå, Sweden.
| | - Erin Schexnaydre
- SciLifeLab Cryo-EM Facility, Department of Chemistry, Umeå University, Umeå, Sweden
| | - Camilla Holmlund
- SciLifeLab Cryo-EM Facility, Department of Chemistry, Umeå University, Umeå, Sweden
| | - Marta Carroni
- SciLifeLab Cryo-EM Facility, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden.
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32
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Peng R, Fu X, Mendez JH, Randolph PS, Bammes BE, Stagg SM. Characterizing the resolution and throughput of the Apollo direct electron detector. J Struct Biol X 2022; 7:100080. [PMID: 36578473 PMCID: PMC9791170 DOI: 10.1016/j.yjsbx.2022.100080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
Advances in electron detection have been essential to the success of high-resolution cryo-EM structure determination. A new generation of direct electron detector called the Apollo, has been developed by Direct Electron. The Apollo uses a novel event-based MAPS detector custom designed for ultra-fast electron counting. We have evaluated this new camera, finding that it delivers high detective quantum efficiency (DQE) and low coincidence loss, enabling high-quality electron counting data acquisition at up to nearly 80 input electrons per pixel per second. We further characterized the performance of Apollo for single particle cryo-EM on real biological samples. Using mouse apoferritin, Apollo yielded better than 1.9 Å resolution reconstructions at all three tested dose rates from a half-day data collection session each. With longer collection time and improved specimen preparation, mouse apoferritin was reconstructed to 1.66 Å resolution. Applied to a more challenging small protein aldolase, we obtained a 2.24 Å resolution reconstruction. The high quality of the map indicates that the Apollo has sufficiently high DQE to reconstruct smaller proteins and complexes with high-fidelity. Our results demonstrate that the Apollo camera performs well across a broad range of dose rates and is capable of capturing high quality data that produce high-resolution reconstructions for large and small single particle samples.
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Affiliation(s)
- Ruizhi Peng
- Institute of Molecular Biophysics, 91 Chieftain Way, Florida State University, Tallahassee, FL 32306, United States
| | - Xiaofeng Fu
- Department of Biological Sciences, 319 Stadium Drive, Tallahassee, FL 32306, United States
| | - Joshua H. Mendez
- Simons Electron Microscopy Center, 89 Convent Avenue, New York, NY 10027, United States
| | - Peter S. Randolph
- Institute of Molecular Biophysics, 91 Chieftain Way, Florida State University, Tallahassee, FL 32306, United States
| | - Benjamin E. Bammes
- Direct Electron LP, 13240 Evening Creek Drive South, Suite 311, San Diego, CA 92128, United States
| | - Scott M. Stagg
- Institute of Molecular Biophysics, 91 Chieftain Way, Florida State University, Tallahassee, FL 32306, United States,Department of Biological Sciences, 319 Stadium Drive, Tallahassee, FL 32306, United States,Corresponding author at: Institute of Molecular Biophysics, 91 Chieftain Way, Florida State University, Tallahassee, FL 32306, United States
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33
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Sheng Y, Harrison PJ, Vogirala V, Yang Z, Strain-Damerell C, Frosio T, Himes BA, Siebert CA, Zhang P, Clare DK. Application of super-resolution and correlative double sampling in cryo-electron microscopy. Faraday Discuss 2022; 240:261-276. [PMID: 35938521 PMCID: PMC9642007 DOI: 10.1039/d2fd00049k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 03/24/2022] [Indexed: 01/09/2023]
Abstract
Developments in cryo-EM have allowed atomic or near-atomic resolution structure determination to become routine in single particle analysis (SPA). However, near-atomic resolution structures determined using cryo-electron tomography and sub-tomogram averaging (cryo-ET STA) are much less routine. In this paper, we show that collecting cryo-ET STA data using the same conditions as SPA, with both correlated double sampling (CDS) and the super-resolution mode, allowed apoferritin to be reconstructed out to the physical Nyquist frequency of the images. Even with just two tilt series, STA yields an apoferritin map at 2.9 Å resolution. These results highlight the exciting potential of cryo-ET STA in the future of protein structure determination. While processing SPA data recorded in super-resolution mode may yield structures surpassing the physical Nyquist limit, processing cryo-ET STA data in the super-resolution mode gave no additional resolution benefit. We further show that collecting SPA data in the super-resolution mode, with CDS activated, reduces the estimated B-factor, leading to a reduction in the number of particles required to reach a target resolution without compromising the data size on disk and the area imaged in SerialEM. However, collecting SPA data in CDS does reduce throughput, given that a similar resolution structure, with a slightly larger B-factor, is achievable with optimised parameters for speed in EPU (without CDS).
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Affiliation(s)
- Yuewen Sheng
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
| | - Peter J Harrison
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
| | - Vinod Vogirala
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
| | - Zhengyi Yang
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
| | - Claire Strain-Damerell
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
- RCaH, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Thomas Frosio
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
| | - Benjamin A Himes
- Howard Hughes Medical Institute, RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - C Alistair Siebert
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
| | - Peijun Zhang
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
- RCaH, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Daniel K Clare
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
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34
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Structures of a phycobilisome in light-harvesting and photoprotected states. Nature 2022; 609:835-845. [PMID: 36045294 DOI: 10.1038/s41586-022-05156-4] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 07/27/2022] [Indexed: 11/08/2022]
Abstract
Phycobilisome (PBS) structures are elaborate antennae in cyanobacteria and red algae1,2. These large protein complexes capture incident sunlight and transfer the energy through a network of embedded pigment molecules called bilins to the photosynthetic reaction centres. However, light harvesting must also be balanced against the risks of photodamage. A known mode of photoprotection is mediated by orange carotenoid protein (OCP), which binds to PBS when light intensities are high to mediate photoprotective, non-photochemical quenching3-6. Here we use cryogenic electron microscopy to solve four structures of the 6.2 MDa PBS, with and without OCP bound, from the model cyanobacterium Synechocystis sp. PCC 6803. The structures contain a previously undescribed linker protein that binds to the membrane-facing side of PBS. For the unquenched PBS, the structures also reveal three different conformational states of the antenna, two previously unknown. The conformational states result from positional switching of two of the rods and may constitute a new mode of regulation of light harvesting. Only one of the three PBS conformations can bind to OCP, which suggests that not every PBS is equally susceptible to non-photochemical quenching. In the OCP-PBS complex, quenching is achieved through the binding of four 34 kDa OCPs organized as two dimers. The complex reveals the structure of the active form of OCP, in which an approximately 60 Å displacement of its regulatory carboxy terminal domain occurs. Finally, by combining our structure with spectroscopic properties7, we elucidate energy transfer pathways within PBS in both the quenched and light-harvesting states. Collectively, our results provide detailed insights into the biophysical underpinnings of the control of cyanobacterial light harvesting. The data also have implications for bioengineering PBS regulation in natural and artificial light-harvesting systems.
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35
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Xue H, Zhang M, Liu J, Wang J, Ren G. Cryo-electron tomography related radiation-damage parameters for individual-molecule 3D structure determination. Front Chem 2022; 10:889203. [PMID: 36110139 PMCID: PMC9468540 DOI: 10.3389/fchem.2022.889203] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 07/13/2022] [Indexed: 11/28/2022] Open
Abstract
To understand the dynamic structure-function relationship of soft- and biomolecules, the determination of the three-dimensional (3D) structure of each individual molecule (nonaveraged structure) in its native state is sought-after. Cryo-electron tomography (cryo-ET) is a unique tool for imaging an individual object from a series of tilted views. However, due to radiation damage from the incident electron beam, the tolerable electron dose limits image contrast and the signal-to-noise ratio (SNR) of the data, preventing the 3D structure determination of individual molecules, especially at high-resolution. Although recently developed technologies and techniques, such as the direct electron detector, phase plate, and computational algorithms, can partially improve image contrast/SNR at the same electron dose, the high-resolution structure, such as tertiary structure of individual molecules, has not yet been resolved. Here, we review the cryo-electron microscopy (cryo-EM) and cryo-ET experimental parameters to discuss how these parameters affect the extent of radiation damage. This discussion can guide us in optimizing the experimental strategy to increase the imaging dose or improve image SNR without increasing the radiation damage. With a higher dose, a higher image contrast/SNR can be achieved, which is crucial for individual-molecule 3D structure. With 3D structures determined from an ensemble of individual molecules in different conformations, the molecular mechanism through their biochemical reactions, such as self-folding or synthesis, can be elucidated in a straightforward manner.
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Affiliation(s)
- Han Xue
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Meng Zhang
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Jianjun Wang
- Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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36
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Kim H, Fu Y, Hong HJ, Lee SG, Lee DS, Kim HM. Structural basis for assembly and disassembly of the IGF/IGFBP/ALS ternary complex. Nat Commun 2022; 13:4434. [PMID: 35907924 PMCID: PMC9338993 DOI: 10.1038/s41467-022-32214-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/21/2022] [Indexed: 11/10/2022] Open
Abstract
Insulin-like growth factors (IGFs) have pleiotropic roles in embryonic and postnatal growth and differentiation. Most serum IGFs are bound in a ternary complex with IGF-binding protein 3 (IGFBP3) and acid-labile subunit (ALS), extending the serum half-life of IGFs and regulating their availability. Here, we report cryo-EM structure of the human IGF1/IGFBP3/ALS ternary complex, revealing the detailed architecture of a parachute-like ternary complex and crucial determinants for their sequential and specific assembly. In vitro biochemical studies show that proteolysis at the central linker domain of IGFBP3 induces release of its C-terminal domain rather than IGF1 release from the ternary complex, yielding an intermediate complex that enhances IGF1 bioavailability. Our results provide mechanistic insight into IGF/IGFBP3/ALS ternary complex assembly and its disassembly upon proteolysis for IGF bioavailability, suggesting a structural basis for human diseases associated with IGF1 and IGFALS gene mutations such as complete ALS deficiency (ACLSD) and IGF1 deficiency. Insulin-like growth factor 1 (IGF1) regulates growth and differentiation. Here, authors report the atomic structure of the ternary complex (IGF1/IGF-binding protein3/acid labile subunit) and its assembly/disassembly mechanism for IGF bioavailability.
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Affiliation(s)
- Hyojin Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Yaoyao Fu
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Ho Jeong Hong
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Seong-Gyu Lee
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Dong Sun Lee
- Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea. .,Center for Biomolecular & Cellular Structure, IBS, Daejeon, 34126, Republic of Korea.
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37
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Chua EYD, Mendez JH, Rapp M, Ilca SL, Tan YZ, Maruthi K, Kuang H, Zimanyi CM, Cheng A, Eng ET, Noble AJ, Potter CS, Carragher B. Better, Faster, Cheaper: Recent Advances in Cryo-Electron Microscopy. Annu Rev Biochem 2022; 91:1-32. [PMID: 35320683 PMCID: PMC10393189 DOI: 10.1146/annurev-biochem-032620-110705] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cryo-electron microscopy (cryo-EM) continues its remarkable growth as a method for visualizing biological objects, which has been driven by advances across the entire pipeline. Developments in both single-particle analysis and in situ tomography have enabled more structures to be imaged and determined to better resolutions, at faster speeds, and with more scientists having improved access. This review highlights recent advances at each stageof the cryo-EM pipeline and provides examples of how these techniques have been used to investigate real-world problems, including antibody development against the SARS-CoV-2 spike during the recent COVID-19 pandemic.
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Affiliation(s)
- Eugene Y D Chua
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Joshua H Mendez
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Micah Rapp
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
| | - Serban L Ilca
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
| | - Yong Zi Tan
- Department of Biological Sciences, National University of Singapore, Singapore;
- Disease Intervention Technology Laboratory, Agency for Science, Technology and Research (A*STAR), Singapore
| | - Kashyap Maruthi
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
| | - Huihui Kuang
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
| | - Christina M Zimanyi
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Anchi Cheng
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
| | - Edward T Eng
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
| | - Alex J Noble
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
- National Center for In-Situ Tomographic Ultramicroscopy, New York, NY, USA
- Simons Machine Learning Center, New York, NY, USA
| | - Clinton S Potter
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
- National Center for In-Situ Tomographic Ultramicroscopy, New York, NY, USA
- Simons Machine Learning Center, New York, NY, USA
| | - Bridget Carragher
- New York Structural Biology Center, New York, NY, USA; , , , , , , , , , , ,
- Simons Electron Microscopy Center, New York, NY, USA
- National Center for CryoEM Access and Training, New York, NY, USA
- National Resource for Automated Molecular Microscopy, New York, NY, USA
- National Center for In-Situ Tomographic Ultramicroscopy, New York, NY, USA
- Simons Machine Learning Center, New York, NY, USA
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38
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Gureyev TE, Paganin DM, Brown HG, Quiney HM, Allen LJ. A Method for High-Resolution Three-Dimensional Reconstruction with Ewald Sphere Curvature Correction from Transmission Electron Images. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 28:1-17. [PMID: 35485646 DOI: 10.1017/s1431927622000630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A method for three-dimensional reconstruction of objects from defocused images collected at multiple illumination directions in high-resolution transmission electron microscopy is presented. The method effectively corrects for the Ewald sphere curvature by taking into account the in-particle propagation of the electron beam. Numerical simulations demonstrate that the proposed method is capable of accurately reconstructing biological molecules or nanoparticles from high-resolution defocused images under conditions achievable in single-particle electron cryo-microscopy or electron tomography with realistic radiation doses, non-trivial aberrations, multiple scattering, and other experimentally relevant factors. The physics of the method is based on the well-known Diffraction Tomography formalism, but with the phase-retrieval step modified to include a conjugation of the phase (i.e., multiplication of the phase by a negative constant). At each illumination direction, numerically backpropagating the beam with the conjugated phase produces maximum contrast at the location of individual atoms in the molecule or nanoparticle. The resultant algorithm, Conjugated Holographic Reconstruction, can potentially be incorporated into established software tools for single-particle analysis, such as, for example, RELION or FREALIGN, in place of the conventional contrast transfer function correction procedure, in order to account for the Ewald sphere curvature and improve the spatial resolution of the three-dimensional reconstruction.
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Affiliation(s)
- Timur E Gureyev
- ARC Centre in Advanced Molecular Imaging, School of Physics, The University of Melbourne, Parkville, VIC3010, Australia
- School of Physics and Astronomy, Monash University, Clayton, VIC3800, Australia
| | - David M Paganin
- School of Physics and Astronomy, Monash University, Clayton, VIC3800, Australia
| | - Hamish G Brown
- ARC Centre in Advanced Molecular Imaging, School of Physics, The University of Melbourne, Parkville, VIC3010, Australia
| | - Harry M Quiney
- ARC Centre in Advanced Molecular Imaging, School of Physics, The University of Melbourne, Parkville, VIC3010, Australia
| | - Leslie J Allen
- ARC Centre in Advanced Molecular Imaging, School of Physics, The University of Melbourne, Parkville, VIC3010, Australia
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39
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Peck JV, Fay JF, Strauss JD. High-speed high-resolution data collection on a 200 keV cryo-TEM. IUCRJ 2022; 9:243-252. [PMID: 35371504 PMCID: PMC8895008 DOI: 10.1107/s2052252522000069] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 01/03/2022] [Indexed: 05/12/2023]
Abstract
Limitations to successful single-particle cryo-electron microscopy (cryo-EM) projects include stable sample generation, production of quality cryo-EM grids with randomly oriented particles embedded in thin vitreous ice and access to microscope time. To address the limitation of microscope time, methodologies to more efficiently collect data on a 200 keV Talos Arctica cryo-transmission electron microscope at speeds as fast as 720 movies per hour (∼17 000 per day) were tested. In this study, key parameters were explored to increase data collection speed including: (1) using the beam-image shift method to acquire multiple images per stage position, (2) employing UltrAufoil TEM grids with R0.6/1 hole spacing, (3) collecting hardware-binned data and (4) adjusting the image shift delay factor in SerialEM. Here, eight EM maps of mouse apoferritin at 1.8-1.9 Å resolution were obtained in the analysis with data collection times for each dataset ranging from 56 min to 2 h. An EM map of mouse apoferritin at 1.78 Å was obtained from an overnight data collection at a speed of 500 movies per hour and subgroup analysis performed, with no significant variation observed in data quality by image shift distance and image shift delay. The findings and operating procedures detailed herein allow for rapid turnover of single-particle cryo-EM structure determination.
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Affiliation(s)
- Jared V. Peck
- Biochemistry and Biophysics, University of North Carolina at Chapel Hill, 101 Mason Farm, Chapel Hill, NC 27599, USA
| | - Jonathan F. Fay
- Biochemistry and Biophysics, 6107 Thurston Bowles Building, Chapel Hill, NC 27599, USA
| | - Joshua D. Strauss
- Biochemistry and Biophysics, University of North Carolina at Chapel Hill, 101 Mason Farm, Chapel Hill, NC 27599, USA
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40
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Blanco-Portals J, Peiró F, Estradé S. Strategies for EELS Data Analysis. Introducing UMAP and HDBSCAN for Dimensionality Reduction and Clustering. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 28:109-122. [PMID: 35177136 DOI: 10.1017/s1431927621013696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Hierarchical density-based spatial clustering of applications with noise (HDBSCAN) and uniform manifold approximation and projection (UMAP), two new state-of-the-art algorithms for clustering analysis, and dimensionality reduction, respectively, are proposed for the segmentation of core-loss electron energy loss spectroscopy (EELS) spectrum images. The performances of UMAP and HDBSCAN are systematically compared to the other clustering analysis approaches used in EELS in the literature using a known synthetic dataset. Better results are found for these new approaches. Furthermore, UMAP and HDBSCAN are showcased in a real experimental dataset from a core–shell nanoparticle of iron and manganese oxides, as well as the triple combination nonnegative matrix factorization–UMAP–HDBSCAN. The results obtained indicate how the complementary use of different combinations may be beneficial in a real-case scenario to attain a complete picture, as different algorithms highlight different aspects of the dataset studied.
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Affiliation(s)
- Javier Blanco-Portals
- LENS-MIND, Department of Electronics and Biomedical Engineering, Universitat de Barcelona, 08028Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, 08028Barcelona, Spain
| | - Francesca Peiró
- LENS-MIND, Department of Electronics and Biomedical Engineering, Universitat de Barcelona, 08028Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, 08028Barcelona, Spain
| | - Sònia Estradé
- LENS-MIND, Department of Electronics and Biomedical Engineering, Universitat de Barcelona, 08028Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, 08028Barcelona, Spain
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