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Egelman EH. Helical reconstruction, again. Curr Opin Struct Biol 2024; 85:102788. [PMID: 38401399 PMCID: PMC10923117 DOI: 10.1016/j.sbi.2024.102788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 01/23/2024] [Accepted: 02/02/2024] [Indexed: 02/26/2024]
Abstract
Many protein and nucleoprotein complexes exist as helical polymers. As a result, much effort has been invested in developing methods for using electron microscopy to determine the structure of these assemblies. With the revolution in cryo-electron microscopy (cryo-EM), it has now become routine to reach a near-atomic level of resolution for these structures, and it is the exception when this is not possible. However, the greatest challenge is frequently determining the correct symmetry. This review focuses on why this can be so difficult and the current absence of a better approach than trial-and-error.
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Affiliation(s)
- Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA 22903, USA.
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2
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Benning FMC, Jenni S, Garcia CY, Nguyen TH, Zhang X, Chao LH. Helical reconstruction of VP39 reveals principles for baculovirus nucleocapsid assembly. Nat Commun 2024; 15:250. [PMID: 38177118 PMCID: PMC10767040 DOI: 10.1038/s41467-023-44596-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: 06/22/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024] Open
Abstract
Baculoviruses are insect-infecting pathogens with wide applications as biological pesticides, in vitro protein production vehicles and gene therapy tools. Its cylindrical nucleocapsid, which encapsulates and protects the circular double-stranded viral DNA encoding proteins for viral replication and entry, is formed by the highly conserved major capsid protein VP39. The mechanism for VP39 assembly remains unknown. We use electron cryomicroscopy to determine a 3.2 Å helical reconstruction of an infectious nucleocapsid of Autographa californica multiple nucleopolyhedrovirus, revealing how dimers of VP39 assemble into a 14-stranded helical tube. We show that VP39 comprises a distinct protein fold conserved across baculoviruses, which includes a Zinc finger domain and a stabilizing intra-dimer sling. Analysis of sample polymorphism shows that VP39 assembles in several closely-related helical geometries. This VP39 reconstruction reveals general principles for baculoviral nucleocapsid assembly.
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Affiliation(s)
- Friederike M C Benning
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA
| | - Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Coby Y Garcia
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
- Harvard College, Cambridge, MA, 02138, USA
| | - Tran H Nguyen
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Xuewu Zhang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Luke H Chao
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, 02114, USA.
- Department of Genetics, Harvard Medical School, Boston, MA, 02115, USA.
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3
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Benning FMC, Jenni S, Garcia CY, Nguyen TH, Zhang X, Chao LH. Helical reconstruction of VP39 reveals principles for baculovirus nucleocapsid assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.15.545104. [PMID: 37398449 PMCID: PMC10312762 DOI: 10.1101/2023.06.15.545104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Baculoviruses are insect-infecting pathogens with wide applications as biological pesticides, in vitro protein production vehicles and gene therapy tools. Its cylindrical nucleocapsid, which encapsulates and protects the circular double-stranded viral DNA encoding proteins for viral replication and entry, is formed by the highly conserved major capsid protein VP39. The mechanism for VP39 assembly remains unknown. We determined a 3.2 Å electron cryomicroscopy helical reconstruction of an infectious nucleocapsid of Autographa californica multiple nucleopolyhedrovirus, revealing how dimers of VP39 assemble into a 14-stranded helical tube. We show that VP39 comprises a unique protein fold conserved across baculoviruses, which includes a Zinc finger domain and a stabilizing intra-dimer sling. Analysis of sample polymorphism revealed that VP39 assembles in several closely-related helical geometries. This VP39 reconstruction reveals general principles for baculoviral nucleocapsid assembly.
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Affiliation(s)
- Friederike M. C. Benning
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
| | - Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Coby Y. Garcia
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Harvard College, Cambridge, MA 02138, USA
| | - Tran H. Nguyen
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Xuewu Zhang
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Luke H. Chao
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
- Department of Genetics, Harvard Medical School, Boston, MA, USA
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4
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Seitz I, Saarinen S, Kumpula EP, McNeale D, Anaya-Plaza E, Lampinen V, Hytönen VP, Sainsbury F, Cornelissen JJLM, Linko V, Huiskonen JT, Kostiainen MA. DNA-origami-directed virus capsid polymorphism. NATURE NANOTECHNOLOGY 2023; 18:1205-1212. [PMID: 37460794 PMCID: PMC10575778 DOI: 10.1038/s41565-023-01443-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 06/06/2023] [Indexed: 10/15/2023]
Abstract
Viral capsids can adopt various geometries, most iconically characterized by icosahedral or helical symmetries. Importantly, precise control over the size and shape of virus capsids would have advantages in the development of new vaccines and delivery systems. However, current tools to direct the assembly process in a programmable manner are exceedingly elusive. Here we introduce a modular approach by demonstrating DNA-origami-directed polymorphism of single-protein subunit capsids. We achieve control over the capsid shape, size and topology by employing user-defined DNA origami nanostructures as binding and assembly platforms, which are efficiently encapsulated within the capsid. Furthermore, the obtained viral capsid coatings can shield the encapsulated DNA origami from degradation. Our approach is, moreover, not limited to a single type of capsomers and can also be applied to RNA-DNA origami structures to pave way for next-generation cargo protection and targeting strategies.
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Affiliation(s)
- Iris Seitz
- Department of Bioproducts and Biosystems, Aalto University, Aalto, Finland
| | - Sharon Saarinen
- Department of Bioproducts and Biosystems, Aalto University, Aalto, Finland
| | - Esa-Pekka Kumpula
- Institute of Biotechnology, Helsinki Institute of Life Science HiLIFE, University of Helsinki, Helsinki, Finland
| | - Donna McNeale
- Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | | | - Vili Lampinen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Vesa P Hytönen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Frank Sainsbury
- Centre for Cell Factories and Biopolymers, Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Jeroen J L M Cornelissen
- Department of Molecules and Materials, MESA+ Institute for Nanotechnology, University of Twente, Enschede, Netherlands
| | - Veikko Linko
- Department of Bioproducts and Biosystems, Aalto University, Aalto, Finland
- LIBER Center of Excellence, Aalto University, Aalto, Finland
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Juha T Huiskonen
- Institute of Biotechnology, Helsinki Institute of Life Science HiLIFE, University of Helsinki, Helsinki, Finland.
| | - Mauri A Kostiainen
- Department of Bioproducts and Biosystems, Aalto University, Aalto, Finland.
- LIBER Center of Excellence, Aalto University, Aalto, Finland.
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5
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Lugmayr W, Kotov V, Goessweiner-Mohr N, Wald J, DiMaio F, Marlovits TC. StarMap: a user-friendly workflow for Rosetta-driven molecular structure refinement. Nat Protoc 2023; 18:239-264. [PMID: 36323866 DOI: 10.1038/s41596-022-00757-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 08/08/2022] [Indexed: 01/13/2023]
Abstract
Cryogenic electron microscopy (cryo-EM) data represent density maps of macromolecular systems at atomic or near-atomic resolution. However, building and refining 3D atomic models by using data from cryo-EM maps is not straightforward and requires significant hands-on experience and manual intervention. We recently developed StarMap, an easy-to-use interface between the popular structural display program ChimeraX and Rosetta, a powerful molecular modeling engine. StarMap offers a general approach for refining structural models of biological macromolecules into cryo-EM density maps by combining Monte Carlo sampling with local density-guided optimization, Rosetta-based all-atom refinement and real-space B-factor calculations in a straightforward workflow. StarMap includes options for structural symmetry, local refinements and independent model validation. The overall quality of the refinement and the structure resolution is then assessed via analytical outputs, such as magnification calibration (pixel size calibration) and Fourier shell correlations. Z-scores reported by StarMap provide an easily interpretable indicator of the goodness of fit for each residue and can be plotted to evaluate structural models and improve local residue refinements, as well as to identify flexible regions and potentially functional sites in large macromolecular complexes. The protocol requires general computer skills, without the need for coding expertise, because most parts of the workflow can be operated by clicking tabs within the ChimeraX graphical user interface. Time requirements for the model refinement depend on the size and quality of the input data; however, this step can typically be completed within 1 d. The analytical parts of the workflow are completed within minutes.
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Affiliation(s)
- Wolfgang Lugmayr
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria
| | - Vadim Kotov
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.,Evotec SE, Hamburg, Germany
| | - Nikolaus Goessweiner-Mohr
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.,Johannes Kepler University, Institute of Biophysics, Linz, Austria
| | - Jiri Wald
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany.,CSSB Centre for Structural Systems Biology, Hamburg, Germany.,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany.,Research Institute of Molecular Pathology (IMP), Vienna, Austria.,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria
| | - Frank DiMaio
- University of Washington, Department of Biochemistry, Seattle, WA, USA
| | - Thomas C Marlovits
- University Medical Center Hamburg-Eppendorf (UKE), Institute of Structural and Systems Biology, Hamburg, Germany. .,CSSB Centre for Structural Systems Biology, Hamburg, Germany. .,Deutsches Elektronen Synchrotron (DESY), Hamburg, Germany. .,Research Institute of Molecular Pathology (IMP), Vienna, Austria. .,Institute for Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.
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6
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Kadamannil NN, Heo JM, Jang D, Zalk R, Kolusheva S, Zarivach R, Frank GA, Kim JM, Jelinek R. High-Resolution Cryo-Electron Microscopy Reveals the Unique Striated Hollow Structure of Photocatalytic Macrocyclic Polydiacetylene Nanotubes. J Am Chem Soc 2022; 144:17889-17896. [PMID: 36126329 DOI: 10.1021/jacs.2c06710] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High-resolution structures are crucial for understanding the functional properties of nanomaterials. We applied single-particle cryo-electron microscopy (cryo-EM), a method traditionally used for structure determination of biological macromolecules, to obtain high-resolution structures of synthetic non-biological filaments formed by photopolymerization of macrocyclic diacetylene (MDA) amphiphilic monomers. Tomographic analysis showed that the MDA monomers self-assemble into hollow nanotubes upon dispersion in water. Single-particle analysis revealed tubes consisting of six pairs of covalently bonded filaments held together by hydrophobic interactions, where each filament is composed of macrocyclic rings stacked in parallel "chair" conformations. The hollow MDA nanotube structures we found may account for the efficient scavenging of amphiphilic pollutants in water and subsequent photodegradation of the guest species.
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Affiliation(s)
| | - Jung-Moo Heo
- Department of Chemical Engineering, Hanyang University, Seoul 04763, Korea
| | - Daewoong Jang
- Department of Chemical Engineering, Hanyang University, Seoul 04763, Korea
| | - Ran Zalk
- Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Sofiya Kolusheva
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.,Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Raz Zarivach
- Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.,The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.,Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Gabriel A Frank
- Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.,The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.,Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
| | - Jong-Man Kim
- Department of Chemical Engineering, Hanyang University, Seoul 04763, Korea
| | - Raz Jelinek
- Department of Chemistry, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel.,Ilse Katz Institute for Nanotechnology, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel
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7
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Conley MJ, Short JM, Burns AM, Streetley J, Hutchings J, Bakker SE, Power BJ, Jaffery H, Haney J, Zanetti G, Murcia PR, Stewart M, Fearns R, Vijayakrishnan S, Bhella D. Helical ordering of envelope-associated proteins and glycoproteins in respiratory syncytial virus. EMBO J 2022; 41:e109728. [PMID: 34935163 PMCID: PMC8804925 DOI: 10.15252/embj.2021109728] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 12/20/2022] Open
Abstract
Human respiratory syncytial virus (RSV) causes severe respiratory illness in children and the elderly. Here, using cryogenic electron microscopy and tomography combined with computational image analysis and three-dimensional reconstruction, we show that there is extensive helical ordering of the envelope-associated proteins and glycoproteins of RSV filamentous virions. We calculated a 16 Å resolution sub-tomogram average of the matrix protein (M) layer that forms an endoskeleton below the viral envelope. These data define a helical lattice of M-dimers, showing how M is oriented relative to the viral envelope. Glycoproteins that stud the viral envelope were also found to be helically ordered, a property that was coordinated by the M-layer. Furthermore, envelope glycoproteins clustered in pairs, a feature that may have implications for the conformation of fusion (F) glycoprotein epitopes that are the principal target for vaccine and monoclonal antibody development. We also report the presence, in authentic virus infections, of N-RNA rings packaged within RSV virions. These data provide molecular insight into the organisation of the virion and the mechanism of its assembly.
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Affiliation(s)
- Michaela J Conley
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
| | - Judith M Short
- Medical Research Council Laboratory of Molecular BiologyCambridgeUK
| | - Andrew M Burns
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
| | - James Streetley
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
| | - Joshua Hutchings
- Department of Biological SciencesBirkbeck CollegeLondonUK
- Present address:
Division of Biological SciencesUniversity of California San DiegoLa JollaCAUSA
| | - Saskia E Bakker
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
- Present address:
School of Life SciencesUniversity of WarwickCoventryUK
| | - B Joanne Power
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
- Present address:
Department of Biochemistry and Molecular BiologyThe Huck Center for Malaria ResearchPennsylvania State UniversityUniversity ParkPAUSA
| | - Hussain Jaffery
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
| | - Joanne Haney
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
| | - Giulia Zanetti
- Department of Biological SciencesBirkbeck CollegeLondonUK
| | - Pablo R Murcia
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
| | - Murray Stewart
- Medical Research Council Laboratory of Molecular BiologyCambridgeUK
| | - Rachel Fearns
- Department of MicrobiologyBoston University School of MedicineBostonMAUSA
- National Emerging Infectious Diseases LaboratoriesBoston UniversityBostonMAUSA
| | | | - David Bhella
- Medical Research Council – University of Glasgow Centre for Virus ResearchGlasgowUK
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