Crystal structure of the vaccine antigen Transferrin Binding Protein B (TbpB) mutant Phe-171-Ala from Actinobacillus pleuropneumoniae H49

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 

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Nonbinding site-directed mutants of transferrin binding protein B exhibit enhanced immunogenicity and protective capabilities.

Frandoloso, R.Martinez-Martinez, S.Calmettes, C.Fegan, J.Costa, E.Curran, D.Yu, R.H.Gutierrez-Martin, C.B.Rodriguez-Ferri, E.F.Moraes, T.F.Schryvers, A.B.

(2015) Infect Immun 83: 1030-1038

  • DOI: https://doi.org/10.1128/IAI.02572-14
  • Primary Citation of Related Structures:  
    4O3W, 4O3X, 4O3Y, 4O3Z, 4O49, 4O4U, 4O4X

  • PubMed Abstract: 

    Host-adapted Gram-negative bacterial pathogens from the Pasteurellaceae, Neisseriaceae, and Moraxellaceae families normally reside in the upper respiratory or genitourinary tracts of their hosts and rely on utilizing iron from host transferrin (Tf) for growth and survival. The surface receptor proteins that mediate this critical iron acquisition pathway have been proposed as ideal vaccine targets due to the critical role that they play in survival and disease pathogenesis in vivo. In particular, the surface lipoprotein component of the receptor, Tf binding protein B (TbpB), had received considerable attention as a potential antigen for vaccines in humans and food production animals but this has not translated into the series of successful vaccine products originally envisioned. Preliminary immunization experiments suggesting that host Tf could interfere with development of the immune response prompted us to directly address this question with site-directed mutant proteins defective in binding Tf. Site-directed mutants with dramatically reduced binding of porcine transferrin and nearly identical structure to the native proteins were prepared. A mutant Haemophilus parasuis TbpB was shown to induce an enhanced B-cell and T-cell response in pigs relative to native TbpB and provide superior protection from infection than the native TbpB or a commercial vaccine product. The results indicate that binding of host transferrin modulates the development of the immune response against TbpBs and that strategies designed to reduce or eliminate binding can be used to generate superior antigens for vaccines.

  • Organizational Affiliation

    Laboratory of Immunology, Faculty of Agronomy and Veterinary Medicine, University of Passo Fundo, São José, Passo Fundo, Brazil Department of Animal Health, University of León, León, Spain.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Transferrin binding protein BA [auth B]255Actinobacillus pleuropneumoniaeMutation(s): 1 
Gene Names: tbpB
Find proteins for G0T4F6 (Actinobacillus pleuropneumoniae)
Explore G0T4F6 
Go to UniProtKB:  G0T4F6
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupG0T4F6
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.195 
  • R-Value Observed: 0.198 
  • Space Group: P 61
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.38α = 90
b = 41.38β = 90
c = 234γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-01-14
    Type: Initial release
  • Version 1.1: 2015-03-04
    Changes: Database references
  • Version 1.2: 2024-02-28
    Changes: Data collection, Database references