3IYK

Bluetongue virus structure reveals a sialic acid binding domain, amphipathic helices and a central coiled coil in the outer capsid proteins


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 7 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Bluetongue virus coat protein VP2 contains sialic acid-binding domains, and VP5 resembles enveloped virus fusion proteins.

Zhang, X.Boyce, M.Bhattacharya, B.Zhang, X.Schein, S.Roy, P.Zhou, Z.H.

(2010) Proc.Natl.Acad.Sci.USA 107: 6292-6297

  • DOI: 10.1073/pnas.0913403107

  • PubMed Abstract: 
  • Bluetongue virus (BTV) is transmitted by blood-feeding insects (Culicoides sp.) and causes hemorrhagic diseases in livestock. BTV is a nonenveloped, double-stranded RNA (dsRNA) virus with two capsids: a well-studied, stable core enclosing the dsRNA g ...

    Bluetongue virus (BTV) is transmitted by blood-feeding insects (Culicoides sp.) and causes hemorrhagic diseases in livestock. BTV is a nonenveloped, double-stranded RNA (dsRNA) virus with two capsids: a well-studied, stable core enclosing the dsRNA genome and a highly unstable, poorly studied coat responsible for host cell attachment and entry. Here, based on cryo-electron microscopy (cryoEM), we report a 7-A resolution structure of the infectious BTV virion, including the coat proteins. We show that unlike other dsRNA viruses, the VP2 attachment trimer has a triskelion shape composed of three tip domains branching from a central hub domain. We identify three putative sialic acid-binding pockets in the hub and present supporting biochemical data indicating sugar moiety binding is important for BTV infection. Despite being a nonenveloped virus, the putative VP5 membrane penetration trimer, located slightly inward of the VP2 attachment trimer, has a central coiled-coil alpha-helical bundle, similar to the fusion proteins of many enveloped viruses (e.g., HIV, herpesviruses, vesicular stomatitis virus, and influenza virus). Moreover, mapping of the amino acid sequence of VP5 to the secondary structural elements identified by cryoEM locates 15 amphipathic alpha-helical regions on the external surface of each VP5 trimer. The cryoEM density map also reveals few, weak interactions between the VP5 trimer and both the outer-coat VP2 trimer and the underlying core VP7 trimer, suggesting that the surface of VP5 could unfurl like an umbrella during penetration and shedding of the coat to release the transcriptionally active core particle.


    Organizational Affiliation

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA 90095-7364, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
VP5
A, B, C, D, E, F
526Bluetongue virus
Find proteins for C5IWW1 (Bluetongue virus)
Go to UniProtKB:  C5IWW1
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
VP2
G, I, K
600Bluetongue virus
Find proteins for C5IWV8 (Bluetongue virus)
Go to UniProtKB:  C5IWV8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MNA
Query on MNA

Download SDF File 
Download CCD File 
G, I, K
2-O-METHYL-5-N-ACETYL-ALPHA-D- NEURAMINIC ACID
C12 H21 N O9
NJRVVFURCKKXOD-MIDKXNQYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 7 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-04-07
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance