4LQF

Structure of murine IgG2b A2C7-Fab in complex with vaccinia antigen A33R at the resolution of 2.3 Angstroms


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 

Starting Models: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structural and Functional Characterization of Anti-A33 Antibodies Reveal a Potent Cross-Species Orthopoxviruses Neutralizer.

Matho, M.H.Schlossman, A.Meng, X.Benhnia, M.R.Kaever, T.Buller, M.Doronin, K.Parker, S.Peters, B.Crotty, S.Xiang, Y.Zajonc, D.M.

(2015) PLoS Pathog 11: e1005148-e1005148

  • DOI: https://doi.org/10.1371/journal.ppat.1005148
  • Primary Citation of Related Structures:  
    4LQF, 4LU5, 4M1G

  • PubMed Abstract: 

    Vaccinia virus A33 is an extracellular enveloped virus (EEV)-specific type II membrane glycoprotein that is essential for efficient EEV formation and long-range viral spread within the host. A33 is a target for neutralizing antibody responses against EEV. In this study, we produced seven murine anti-A33 monoclonal antibodies (MAbs) by immunizing mice with live VACV, followed by boosting with the soluble A33 homodimeric ectodomain. Five A33 specific MAbs were capable of neutralizing EEV in the presence of complement. All MAbs bind to conformational epitopes on A33 but not to linear peptides. To identify the epitopes, we have adetermined the crystal structures of three representative neutralizing MAbs in complex with A33. We have further determined the binding kinetics for each of the three antibodies to wild-type A33, as well as to engineered A33 that contained single alanine substitutions within the epitopes of the three crystallized antibodies. While the Fab of both MAbs A2C7 and A20G2 binds to a single A33 subunit, the Fab from MAb A27D7 binds to both A33 subunits simultaneously. A27D7 binding is resistant to single alanine substitutions within the A33 epitope. A27D7 also demonstrated high-affinity binding with recombinant A33 protein that mimics other orthopoxvirus strains in the A27D7 epitope, such as ectromelia, monkeypox, and cowpox virus, suggesting that A27D7 is a potent cross-neutralizer. Finally, we confirmed that A27D7 protects mice against a lethal challenge with ectromelia virus.


  • Organizational Affiliation

    Division of Cell Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, United States of America.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A33R97Vaccinia virusMutation(s): 4 
UniProt
Find proteins for Q71TT1 (Vaccinia virus)
Explore Q71TT1 
Go to UniProtKB:  Q71TT1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ71TT1
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Murine IgG2b A2C7 Heavy chain Fab domainB [auth H]216Mus musculusMutation(s): 0 
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Sequence Annotations
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Murine IgG2b A2C7 Light chain Fab domainC [auth L]219Mus musculusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.28α = 90
b = 73.18β = 90
c = 221.6γ = 90
Software Package:
Software NamePurpose
iMOSFLMdata reduction
PHASERphasing
REFMACrefinement
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-08-06
    Type: Initial release
  • Version 1.1: 2015-09-23
    Changes: Database references
  • Version 1.2: 2020-03-18
    Changes: Database references, Derived calculations
  • Version 1.3: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.4: 2024-10-09
    Changes: Structure summary