+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-42600 | |||||||||
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Title | Murine norovirus in the presence of 1mM calcium | |||||||||
Map data | Murine norovirus in the presence of calcium | |||||||||
Sample |
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Keywords | murine / norovirus / metals / activation / VIRAL PROTEIN | |||||||||
Function / homology | Calicivirus coat protein C-terminal / Calicivirus coat protein C-terminal / Calicivirus coat protein / Calicivirus coat protein / Picornavirus/Calicivirus coat protein / virion component / Viral coat protein subunit / : / Capsid protein Function and homology information | |||||||||
Biological species | Murine norovirus 1 | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.74 Å | |||||||||
Authors | Smith TJ | |||||||||
Funding support | United States, 1 items
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Citation | Journal: J Virol / Year: 2024 Title: The reversible activation of norovirus by metal ions. Authors: Michael Sherman / Faith Cox / Hong Smith / Mohamed H Habib / Stephanie Karst / Christiane E Wobus / Thomas J Smith / Abstract: Murine norovirus (MNV) undergoes extremely large conformational changes in response to the environment. The = 3 icosahedral capsid is composed of 180 copies of ~58-kDa VP1 comprised of N-terminus (N) ...Murine norovirus (MNV) undergoes extremely large conformational changes in response to the environment. The = 3 icosahedral capsid is composed of 180 copies of ~58-kDa VP1 comprised of N-terminus (N), shell (S), and C-terminal protruding (P) domains. At neutral pH, the P domains are loosely tethered to the shell and float ~15 Å above the surface. At low pH or in the presence of bile salts, the P domain drops onto the shell and this movement is accompanied by conformational changes within the P domain that enhance receptor interactions while blocking antibody binding. While previous crystallographic studies identified metal binding sites in the isolated P domain, the ~2.7-Å cryo-electron microscopy structures of MNV in the presence of Mg or Ca presented here show that metal ions can recapitulate the contraction observed at low pH or in the presence of bile. Further, we show that these conformational changes are reversed by dialysis against EDTA. As observed in the P domain crystal structures, metal ions bind to and contract the G'H' loop. This movement is correlated with the lifting of the C'D' loop and rotation of the P domain dimers about each other, exposing the bile salt binding pocket. Isothermal titration calorimetry experiments presented here demonstrate that the activation signals (bile salts, low pH, and metal ions) act in a synergistic manner that, individually, all result in the same activated structure. We present a model whereby these reversible conformational changes represent a uniquely dynamic and tissue-specific structural adaptation to the environment.IMPORTANCEThe highly mobile protruding domains on the calicivirus capsids are recognized by cell receptor(s) and antibodies. At neutral pH, they float ~15 Å above the shell but at low pH or in the presence of bile salts, they contract onto the surface. Concomitantly, changes within the P domain block antibody binding while enhancing receptor binding. While we previously demonstrated that metals also block antibody binding, it was unknown whether they might also cause similar conformational changes in the virion. Here, we present the near atomic cryo-electron microscopy structures of infectious murine norovirus (MNV) in the presence of calcium or magnesium ions. The metal ions reversibly induce the same P domain contraction as low pH and bile salts and act in a synergistic manner with the other stimuli. We propose that, unlike most other viruses, MNV facilely changes conformations as a unique means to escape immune surveillance as it moves through various tissues. | |||||||||
History |
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-Structure visualization
Supplemental images |
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-Downloads & links
-EMDB archive
Map data | emd_42600.map.gz | 567.2 MB | EMDB map data format | |
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Header (meta data) | emd-42600-v30.xml emd-42600.xml | 14.4 KB 14.4 KB | Display Display | EMDB header |
Images | emd_42600.png | 260 KB | ||
Filedesc metadata | emd-42600.cif.gz | 5.2 KB | ||
Others | emd_42600_half_map_1.map.gz emd_42600_half_map_2.map.gz | 555.8 MB 555.8 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-42600 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-42600 | HTTPS FTP |
-Validation report
Summary document | emd_42600_validation.pdf.gz | 1012 KB | Display | EMDB validaton report |
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Full document | emd_42600_full_validation.pdf.gz | 1011.6 KB | Display | |
Data in XML | emd_42600_validation.xml.gz | 19.7 KB | Display | |
Data in CIF | emd_42600_validation.cif.gz | 23.4 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-42600 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-42600 | HTTPS FTP |
-Related structure data
Related structure data | 8uuxMC 8uv3C C: citing same article (ref.) M: atomic model generated by this map |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_42600.map.gz / Format: CCP4 / Size: 600.7 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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Annotation | Murine norovirus in the presence of calcium | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.1 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Half map: MNV calcium half map A
File | emd_42600_half_map_1.map | ||||||||||||
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Annotation | MNV calcium half map A | ||||||||||||
Projections & Slices |
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Density Histograms |
-Half map: MNV calcium half map B
File | emd_42600_half_map_2.map | ||||||||||||
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Annotation | MNV calcium half map B | ||||||||||||
Projections & Slices |
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Density Histograms |
-Sample components
-Entire : Murine norovirus 1
Entire | Name: Murine norovirus 1 |
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Components |
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-Supramolecule #1: Murine norovirus 1
Supramolecule | Name: Murine norovirus 1 / type: virus / ID: 1 / Parent: 0 / Macromolecule list: #1 / NCBI-ID: 223997 / Sci species name: Murine norovirus 1 / Virus type: VIRION / Virus isolate: STRAIN / Virus enveloped: No / Virus empty: No |
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-Macromolecule #1: Capsid protein
Macromolecule | Name: Capsid protein / type: protein_or_peptide / ID: 1 / Number of copies: 3 / Enantiomer: LEVO |
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Source (natural) | Organism: Murine norovirus 1 |
Molecular weight | Theoretical: 56.136617 KDa |
Sequence | String: SGQDLVPAAV EQAVPIQPVA GAALAAPAAG QINQIDPWIF QNFVQCPLGE FSISPRNTPG EILFDLALGP GLNPYLAHLS AMYTGWVGN MEVQLVLAGN AFTAGKVVVA LVPPYFPKGS LTTAQITCFP HVMCDVRTLE PIQLPLLDVR RVLWHATQDQ E ESMRLVCM ...String: SGQDLVPAAV EQAVPIQPVA GAALAAPAAG QINQIDPWIF QNFVQCPLGE FSISPRNTPG EILFDLALGP GLNPYLAHLS AMYTGWVGN MEVQLVLAGN AFTAGKVVVA LVPPYFPKGS LTTAQITCFP HVMCDVRTLE PIQLPLLDVR RVLWHATQDQ E ESMRLVCM LYTPLRTNSP GDESFVVSGR LLSKPAADFN FVYLTPPIER TIYRMVDLPV IQPRLCTHAR WPAPVYGLLV DP SLPSNPQ WQNGRVHVDG TLLGTTPISG SWVSCFAAEA AYEFQSGTGE VATFTLIEQD GSAYVPGDRA APLGYPDFSG QLE IEIQTE TTKTGDKLKV TTFEMILGPT TNADQAPYQG RVFASVTAAA SLDLVDGRVR AVPRSIYGFQ DTIPEYNDGL LVPL APPIG PFLPGEVLLR FRTYMRQIDT ADAAAEAIDC ALPQEFVSWF ASNAFTVQSE ALLLRYRNTL TGQLLFECKL YNEGY IALS YSGSGPLTFP TDGIFEVVSW VPRLYQLASV GS UniProtKB: Capsid protein |
-Macromolecule #2: CALCIUM ION
Macromolecule | Name: CALCIUM ION / type: ligand / ID: 2 / Number of copies: 3 / Formula: CA |
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Molecular weight | Theoretical: 40.078 Da |
-Macromolecule #3: water
Macromolecule | Name: water / type: ligand / ID: 3 / Number of copies: 310 / Formula: HOH |
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Molecular weight | Theoretical: 18.015 Da |
Chemical component information | ChemComp-HOH: |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.4 |
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Vitrification | Cryogen name: ETHANE-PROPANE |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average electron dose: 48.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: SPOT SCAN / Imaging mode: BRIGHT FIELD / Nominal defocus max: 2.5 µm / Nominal defocus min: 1.5 µm |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Startup model | Type of model: NONE |
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Final reconstruction | Resolution.type: BY AUTHOR / Resolution: 2.74 Å / Resolution method: FSC 0.143 CUT-OFF / Number images used: 77727 |
Initial angle assignment | Type: NOT APPLICABLE |
Final angle assignment | Type: NOT APPLICABLE |