6EDJ

Cryo-EM structure of Woodchuck hepatitis virus capsid


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.52 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural Differences between the Woodchuck Hepatitis Virus Core Protein in the Dimer and Capsid States Are Consistent with Entropic and Conformational Regulation of Assembly.

Zhao, Z.Wang, J.C.Gonzalez-Gutierrez, G.Venkatakrishnan, B.Asor, R.Khaykelson, D.Raviv, U.Zlotnick, A.

(2019) J Virol 93

  • DOI: 10.1128/JVI.00141-19
  • Primary Citation of Related Structures:  
    6ECS, 6EDJ

  • PubMed Abstract: 
  • Hepadnaviruses are hepatotropic enveloped DNA viruses with an icosahedral capsid. Hepatitis B virus (HBV) causes chronic infection in an estimated 240 million people; woodchuck hepatitis virus (WHV), an HBV homologue, has been an important model system for drug development ...

    Hepadnaviruses are hepatotropic enveloped DNA viruses with an icosahedral capsid. Hepatitis B virus (HBV) causes chronic infection in an estimated 240 million people; woodchuck hepatitis virus (WHV), an HBV homologue, has been an important model system for drug development. The dimeric capsid protein (Cp) has multiple functions during the viral life cycle and thus has become an important target for a new generation of antivirals. Purified HBV and WHV Cp spontaneously assemble into 120-dimer capsids. Though they have 65% identity, WHV Cp has error-prone assembly with stronger protein-protein association. We have taken advantage of the differences in assemblies to investigate the basis of assembly regulation. We determined the structures of the WHV capsid to 4.5-Å resolution by cryo-electron microscopy (cryo-EM) and of the WHV Cp dimer to 2.9-Å resolution by crystallography and examined the biophysical properties of the dimer. We found, in dimer, that the subdomain that makes protein-protein interactions is partially disordered and rotated 21° from its position in capsid. This subdomain is susceptible to proteolysis, consistent with local disorder. WHV assembly shows similar susceptibility to HBV antiviral molecules, suggesting that HBV assembly follows similar transitions. These data show that there is an entropic cost for assembly that is compensated for by the energetic gain of burying hydrophobic interprotein contacts. We propose a series of stages in assembly that incorporate a disorder-to-order transition and structural shifts. We suggest that a cascade of structural changes may be a common mechanism for regulating high-fidelity capsid assembly in HBV and other viruses. IMPORTANCE Virus capsids assemble spontaneously with surprisingly high fidelity. This requires strict geometry and a narrow range of association energies for these protein-protein interactions. It was hypothesized that requiring subunits to undergo a conformational change to become assembly active could regulate assembly by creating an energetic barrier and attenuating association. We found that woodchuck hepatitis virus capsid protein undergoes structural transitions between its dimeric and its 120-dimer capsid states. It is likely that the closely related hepatitis B virus capsid protein undergoes similar structural changes, which has implications for drug design. Regulation of assembly by structural transition may be a common mechanism for many viruses.


    Organizational Affiliation

    Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana, USA azlotnic@indiana.edu.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
External core antigenA, B, C, D149Woodchuck hepatitis virusMutation(s): 0 
UniProt
Find proteins for P0C6J2 (Woodchuck hepatitis B virus (isolate 1))
Explore P0C6J2 
Go to UniProtKB:  P0C6J2
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.52 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute Of Allergy and Infectious Diseases (NIH/NIAID)United StatesR01-AI11893

Revision History  (Full details and data files)

  • Version 1.0: 2019-05-01
    Type: Initial release
  • Version 1.1: 2019-11-13
    Changes: Database references
  • Version 1.2: 2019-12-18
    Changes: Author supporting evidence