+Open data
-Basic information
Entry | Database: PDB / ID: 7vrt | |||||||||
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Title | The unexpanded head structure of phage T4 | |||||||||
Components |
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Keywords | VIRUS / virus assembly / capsid expansion / capsid length control / prolate virus structure / virus decoration proteins / capsid stabilization | |||||||||
Function / homology | Capsid vertex protein / Major capsid protein, Myoviridae / Major capsid protein Gp23 / Capsid protein, T4-like bacteriophage-like / T=13 icosahedral viral capsid / viral capsid / Major capsid protein / Capsid vertex protein Function and homology information | |||||||||
Biological species | Enterobacteria phage T4 (virus) | |||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 5.1 Å | |||||||||
Authors | Fang, Q. / Tang, W. / Fokine, A. / Mahalingam, M. / Shao, Q. / Rossmann, M.G. / Rao, V.B. | |||||||||
Funding support | United States, 2items
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Citation | Journal: Proc Natl Acad Sci U S A / Year: 2022 Title: Structures of a large prolate virus capsid in unexpanded and expanded states generate insights into the icosahedral virus assembly. Authors: Qianglin Fang / Wei-Chun Tang / Andrei Fokine / Marthandan Mahalingam / Qianqian Shao / Michael G Rossmann / Venigalla B Rao / Abstract: Many icosahedral viruses assemble proteinaceous precursors called proheads or procapsids. Proheads are metastable structures that undergo a profound structural transition known as expansion that ...Many icosahedral viruses assemble proteinaceous precursors called proheads or procapsids. Proheads are metastable structures that undergo a profound structural transition known as expansion that transforms an immature unexpanded head into a mature genome-packaging head. Bacteriophage T4 is a model virus, well studied genetically and biochemically, but its structure determination has been challenging because of its large size and unusually prolate-shaped, ∼1,200-Å-long and ∼860-Å-wide capsid. Here, we report the cryogenic electron microscopy (cryo-EM) structures of T4 capsid in both of its major conformational states: unexpanded at a resolution of 5.1 Å and expanded at a resolution of 3.4 Å. These are among the largest structures deposited in Protein Data Bank to date and provide insights into virus assembly, head length determination, and shell expansion. First, the structures illustrate major domain movements and ∼70% additional gain in inner capsid volume, an essential transformation to contain the entire viral genome. Second, intricate intracapsomer interactions involving a unique insertion domain dramatically change, allowing the capsid subunits to rotate and twist while the capsomers remain fastened at quasi-threefold axes. Third, high-affinity binding sites emerge for a capsid decoration protein that clamps adjacent capsomers, imparting extraordinary structural stability. Fourth, subtle conformational changes at capsomers' periphery modulate intercapsomer angles between capsomer planes that control capsid length. Finally, conformational changes were observed at the symmetry-mismatched portal vertex, which might be involved in triggering head expansion. These analyses illustrate how small changes in local capsid subunit interactions lead to profound shifts in viral capsid morphology, stability, and volume. | |||||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 7vrt.cif.gz | 12.4 MB | Display | PDBx/mmCIF format |
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PDB format | pdb7vrt.ent.gz | Display | PDB format | |
PDBx/mmJSON format | 7vrt.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 7vrt_validation.pdf.gz | 3 MB | Display | wwPDB validaton report |
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Full document | 7vrt_full_validation.pdf.gz | 3.1 MB | Display | |
Data in XML | 7vrt_validation.xml.gz | 1.4 MB | Display | |
Data in CIF | 7vrt_validation.cif.gz | 2.3 MB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/vr/7vrt ftp://data.pdbj.org/pub/pdb/validation_reports/vr/7vrt | HTTPS FTP |
-Related structure data
Related structure data | 32103MC 7vs5C M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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Symmetry | Point symmetry: (Schoenflies symbol: C5 (5 fold cyclic)) |
-Components
#1: Protein | Mass: 56074.242 Da / Num. of mol.: 180 / Source method: isolated from a natural source / Source: (natural) Enterobacteria phage T4 (virus) / References: UniProt: P04535 #2: Protein | Mass: 47039.023 Da / Num. of mol.: 11 / Source method: isolated from a natural source / Source: (natural) Enterobacteria phage T4 (virus) / References: UniProt: P19896 |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
-Sample preparation
Component | Name: Escherichia virus T4 / Type: VIRUS / Entity ID: all / Source: NATURAL |
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Molecular weight | Experimental value: NO |
Source (natural) | Organism: Escherichia virus T4 |
Details of virus | Empty: YES / Enveloped: NO / Isolate: STRAIN / Type: VIRION |
Natural host | Organism: Escherichia coli |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Instrument: GATAN CRYOPLUNGE 3 / Cryogen name: NITROGEN |
-Electron microscopy imaging
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD |
Image recording | Electron dose: 25.3 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
-Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION |
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Symmetry | Point symmetry: C5 (5 fold cyclic) |
3D reconstruction | Resolution: 5.1 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 28706 / Symmetry type: POINT |