[English] 日本語
Yorodumi
- PDB-6dzu: Mechanism of cellular recognition by PCV2 -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: PDB / ID: 6dzu
TitleMechanism of cellular recognition by PCV2
ComponentsPutative capsid protein
KeywordsVIRUS LIKE PARTICLE / viral jelly-roll
Function / homologyCircovirus capsid protein / Circovirus capsid superfamily / Circovirus capsid protein / viral capsid assembly / T=1 icosahedral viral capsid / symbiont entry into host cell / virion attachment to host cell / Putative capsid protein
Function and homology information
Biological speciesPorcine circovirus 2
MethodELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.3 Å
Model detailsCryo-EM image reconstruction at 3.2Angstrom resolution
AuthorsKhayat, R. / Dhindwal, S.
Funding support United States, 1items
OrganizationGrant numberCountry
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)5SC1AI114843 United States
CitationJournal: J Virol / Year: 2019
Title: Porcine Circovirus 2 Uses a Multitude of Weak Binding Sites To Interact with Heparan Sulfate, and the Interactions Do Not Follow the Symmetry of the Capsid.
Authors: Sonali Dhindwal / Bryant Avila / Shanshan Feng / Reza Khayat /
Abstract: Porcine circovirus 2 (PCV2) is the smallest pathogenic virus capable of autonomous replication within its host. Infections result in immunosuppression and subsequent death of the host and are ...Porcine circovirus 2 (PCV2) is the smallest pathogenic virus capable of autonomous replication within its host. Infections result in immunosuppression and subsequent death of the host and are initiated via the attachment of the PCV2 icosahedral capsid to heparan sulfate (HS) and chondroitin sulfate B (CSB) glycosaminoglycans on the cell surface. However, the underlying mechanism of structural recognition remains to be explored. Using heparin, a routinely used analog of heparan sulfate, we demonstrate that increasing lengths of heparin exhibit a greater affinity toward PCV2. Our competition assays indicate that dextran sulfate (8 kDa) has a higher affinity for PCV2 than heparin (12 kDa), chondroitin sulfate B (41 kDa), hyaluronic acid (1.6 MDa), and dextran (6 kDa). This suggests that polymers high in sulfate content are capable of competing with the PCV2-heparan sulfate interaction and, thus, have the potential to inhibit PCV2 infection. Finally, we visualized the interaction between heparin and the PCV2 capsid using cryo-electron microscopy single-particle analysis, symmetry expansion, and focused classification. The image reconstructions provide the first example of an asymmetric distribution of heparin on the surface of an icosahedral virus capsid. We demonstrate that each of the 60 capsid subunits that generate the T1 capsid can bind heparin via one of five binding sites. However, not all of the binding sites were occupied by heparin, and only one-third to two-thirds of the binding sites were occupied. The binding sites are defined by arginine, lysine, and polar amino acids. Mutating the arginine, lysine, and polar amino acids to alanine diminished the binding capacity of PCV2 to heparin. It has been demonstrated that porcine circovirus 2 (PCV2) attaches to cells via heparan sulfate (HS) and chondroitin sulfate B (CSB) glycosaminoglycans; however, the underlying structural mechanism describing the HS/CSB recognition by PCV2 remains to be explored. We used cryo-electron microscopy with single-particle analysis, symmetry expansion, and focused classification to visualize the interaction between the PCV2 capsid and heparin, an analog of heparan sulfate, to better than 3.6-Å resolution. We observed that the interaction between PCV2 and heparin does not adhere to the icosahedral symmetry of the capsid. To the best of our knowledge, this is the first example where the interaction between heparin and an icosahedral capsid does not follow the symmetry elements of the capsid. Our findings also suggest that anionic polymers, such as dextran sulfate, may act to inhibit PCV2 infection.
History
DepositionJul 5, 2018Deposition site: RCSB / Processing site: RCSB
Revision 1.0Dec 26, 2018Provider: repository / Type: Initial release
Revision 1.1Dec 18, 2019Group: Author supporting evidence / Database references / Category: citation_author / pdbx_audit_support
Item: _citation_author.name / _pdbx_audit_support.funding_organization
Revision 1.2Mar 13, 2024Group: Data collection / Database references / Category: chem_comp_atom / chem_comp_bond / database_2
Item: _database_2.pdbx_DOI / _database_2.pdbx_database_accession

-
Structure visualization

Movie
  • Deposited structure unit
  • Imaged by Jmol
  • Download
  • Simplified surface model + fitted atomic model
  • EMDB-8939
  • Imaged by Jmol
  • Download
  • Superimposition on EM map
  • EMDB-8939
  • Imaged by UCSF Chimera
  • Download
Movie viewer
Structure viewerMolecule:
MolmilJmol/JSmol

Downloads & links

-
Assembly

Deposited unit
A1: Putative capsid protein
A2: Putative capsid protein
A3: Putative capsid protein
A4: Putative capsid protein
A5: Putative capsid protein
A6: Putative capsid protein
A7: Putative capsid protein
A8: Putative capsid protein
A9: Putative capsid protein
AA: Putative capsid protein
AB: Putative capsid protein
AC: Putative capsid protein
AD: Putative capsid protein
AE: Putative capsid protein
AF: Putative capsid protein
AG: Putative capsid protein
AH: Putative capsid protein
AI: Putative capsid protein
AJ: Putative capsid protein
AK: Putative capsid protein
AL: Putative capsid protein
AM: Putative capsid protein
AN: Putative capsid protein
AO: Putative capsid protein
AP: Putative capsid protein
AQ: Putative capsid protein
AR: Putative capsid protein
AS: Putative capsid protein
AT: Putative capsid protein
AU: Putative capsid protein
AV: Putative capsid protein
AW: Putative capsid protein
AX: Putative capsid protein
AY: Putative capsid protein
AZ: Putative capsid protein
Aa: Putative capsid protein
Ab: Putative capsid protein
Ac: Putative capsid protein
Ad: Putative capsid protein
Ae: Putative capsid protein
Af: Putative capsid protein
Ag: Putative capsid protein
Ah: Putative capsid protein
Ai: Putative capsid protein
Aj: Putative capsid protein
Ak: Putative capsid protein
Al: Putative capsid protein
Am: Putative capsid protein
An: Putative capsid protein
Ao: Putative capsid protein
Ap: Putative capsid protein
Aq: Putative capsid protein
Ar: Putative capsid protein
As: Putative capsid protein
At: Putative capsid protein
Au: Putative capsid protein
Av: Putative capsid protein
Aw: Putative capsid protein
Ax: Putative capsid protein
Ay: Putative capsid protein


Theoretical massNumber of molelcules
Total (without water)1,314,82060
Polymers1,314,82060
Non-polymers00
Water00
1


  • Idetical with deposited unit
  • defined by author
TypeNameSymmetry operationNumber
identity operation1_5551

-
Components

#1: Protein ...
Putative capsid protein


Mass: 21913.668 Da / Num. of mol.: 60 / Fragment: Capsid protein / Mutation: None
Source method: isolated from a genetically manipulated source
Source: (gene. exp.) Porcine circovirus 2 / Gene: ORF2 / Plasmid: pFastBac1 / Production host: Trichoplusia ni (cabbage looper) / Strain (production host): High Five / References: UniProt: G0ZPJ2

-
Experimental details

-
Experiment

ExperimentMethod: ELECTRON MICROSCOPY
EM experimentAggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction

-
Sample preparation

ComponentName: PCV2 / Type: VIRUS / Entity ID: all
Molecular weightUnits: KILODALTONS/NANOMETER / Experimental value: NO
Source (natural)Organism: Porcine circovirus 2
Details of virusEmpty: NO / Enveloped: NO / Isolate: SPECIES / Type: VIRUS-LIKE PARTICLE
Natural hostOrganism: Sus scrofa
Virus shellName: Capsid protein / Diameter: 215 nm / Triangulation number (T number): 1
Buffer solutionpH: 7
Buffer component
IDConc.NameFormulaBuffer-ID
120 mM(4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid)HEPES1
2250 mMSodium ChlorideNaCl1
30.1 mMTris(2-carboxyethyl)phosphineTCEP1
42 mMEthylenediaminetetraacetic acidEDTA1
SpecimenConc.: 0.718 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES / Details: This sample was monodisperse
Specimen supportDetails: Grids are from TedPella: 01824 / Grid material: COPPER / Grid mesh size: 400 divisions/in. / Grid type: Homemade
VitrificationInstrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 4 K

-
Electron microscopy imaging

MicroscopyModel: FEI TITAN
Electron gunElectron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM
Electron lensMode: BRIGHT FIELD / Calibrated defocus min: 280 nm / Calibrated defocus max: 3200 nm / Cs: 2.7 mm / C2 aperture diameter: 100 µm / Alignment procedure: COMA FREE
Specimen holderCryogen: NITROGEN
Image recordingAverage exposure time: 5 sec. / Electron dose: 35 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 1149
Image scansMovie frames/image: 50 / Used frames/image: 2-50

-
Processing

EM software
IDNameCategoryDetails
2Leginonimage acquisition
4GctfCTF correctionPer particle estimation
7Cootmodel fitting
9RELIONinitial Euler assignment
10cryoSPARCfinal Euler assignment
11RELIONclassification
12cryoSPARC3D reconstruction
13PHENIXmodel refinement
CTF correctionDetails: Per particle estimation / Type: PHASE FLIPPING AND AMPLITUDE CORRECTION
Particle selectionNum. of particles selected: 54409
SymmetryPoint symmetry: I (icosahedral)
3D reconstructionResolution: 3.3 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 28938 / Algorithm: FOURIER SPACE / Symmetry type: POINT
Atomic model buildingB value: 35.5 / Protocol: FLEXIBLE FIT / Space: REAL / Target criteria: Correlation coefficient

+
About Yorodumi

-
News

-
Feb 9, 2022. New format data for meta-information of EMDB entries

New format data for meta-information of EMDB entries

  • Version 3 of the EMDB header file is now the official format.
  • The previous official version 1.9 will be removed from the archive.

Related info.:EMDB header

External links:wwPDB to switch to version 3 of the EMDB data model

-
Aug 12, 2020. Covid-19 info

Covid-19 info

URL: https://pdbj.org/emnavi/covid19.php

New page: Covid-19 featured information page in EM Navigator.

Related info.:Covid-19 info / Mar 5, 2020. Novel coronavirus structure data

+
Mar 5, 2020. Novel coronavirus structure data

Novel coronavirus structure data

Related info.:Yorodumi Speices / Aug 12, 2020. Covid-19 info

External links:COVID-19 featured content - PDBj / Molecule of the Month (242):Coronavirus Proteases

+
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)

EMDB accession codes are about to change! (news from PDBe EMDB page)

  • The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
  • The EM Navigator/Yorodumi systems omit the EMD- prefix.

Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator

External links:EMDB Accession Codes are Changing Soon! / Contact to PDBj

+
Jul 12, 2017. Major update of PDB

Major update of PDB

  • wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary.
  • This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated.
  • In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software).
  • Now, EM Navigator and Yorodumi are based on the updated data.

External links:wwPDB Remediation / Enriched Model Files Conforming to OneDep Data Standards Now Available in the PDB FTP Archive

-
Yorodumi

Thousand views of thousand structures

  • Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
  • This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
  • The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.

Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi

Read more