2EJN

Structural characterization of the tetrameric form of the major cat allergen fel D 1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.64 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.190 

Starting Model: experimental
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This is version 1.5 of the entry. See complete history


Literature

Structural characterization of the tetrameric form of the major cat allergen Fel d 1

Kaiser, L.Velickovic, T.C.Badia-Martinez, D.Adedoyin, J.Thunberg, S.Hallen, D.Berndt, K.Gronlund, H.Gafvelin, G.van Hage, M.Achour, A.

(2007) J Mol Biol 370: 714-727

  • DOI: https://doi.org/10.1016/j.jmb.2007.04.074
  • Primary Citation of Related Structures:  
    2EJN

  • PubMed Abstract: 

    Felis domesticus allergen 1(Fel d 1) is a 35 kDa tetrameric glycoprotein formed by two heterodimers which elicits IgE responses in 95% of patients with allergy to cat. We have previously established in vitro conditions for the appropriate folding of recombinant Fel d 1 using a direct linkage of chain 1 to chain 2 (construct Fel d 1 (1+2)) and chain 2 to chain 1 (construct Fel d 1 (2+1)). Although the crystal structure of Fel d 1 (2+1) revealed a striking structural similarity to that of uteroglobin, a steroid-inducible cytokine-like molecule with anti-inflammatory and immunomodulatory properties, no functional tetrameric form of Fel d 1 could be identified. Here we present the crystal structure of the Fel d 1 (1+2) tetramer at 1.6 A resolution. Interestingly, the crystal structure of tetrameric Fel d 1 reveals two different calcium-binding sites. Symmetrically positioned on each side of the Fel d 1 tetramer, the external Ca(2+)-binding sites correspond to a putative Ca(2+)-binding site previously suggested for uteroglobin. The second Ca(2+)-binding site lies within the dimerization interface, stabilizing the formation of the Fel d 1 tetramer, and inducing important local conformational changes that directly govern the shape of two water-filled cavities. The crystal structure suggests a potential portal for an unknown ligand. Alternatively, the two cavities could be used by the allergen as a conditional inner space allowing for the spatial rearrangement of centrally localized side-chains, such as Asp130, without altering the overall fold of the molecule. The striking structural similarity of the major cat allergen to uteroglobin, coupled to the identification in the present study of a common Ca(2+)-binding site, let us speculate that Fel d 1 could provoke an allergic response through the modulation of phospholipase A2, by sequestering Ca ions in a similar manner as previously suggested for uteroglobin.


  • Organizational Affiliation

    Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Major allergen I polypeptide chain 1, chain 2
A, B
153Felis catusMutation(s): 0 
Gene Names: ch1ch2
UniProt
Find proteins for P30438 (Felis catus)
Explore P30438 
Go to UniProtKB:  P30438
Find proteins for P30440 (Felis catus)
Explore P30440 
Go to UniProtKB:  P30440
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupsP30438P30440
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.64 Å
  • R-Value Free: 0.220 
  • R-Value Work: 0.190 
  • R-Value Observed: 0.190 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 38.588α = 70.8
b = 42.996β = 80.56
c = 48.906γ = 81.53
Software Package:
Software NamePurpose
ADSCdata collection
MOLREPphasing
REFMACrefinement
MOSFLMdata reduction
CCP4data scaling

Structure Validation

View Full Validation Report



Entry History 

Revision History  (Full details and data files)

  • Version 1.0: 2007-04-17
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-08-16
    Changes: Data collection, Refinement description, Source and taxonomy
  • Version 1.4: 2023-10-25
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.5: 2024-11-06
    Changes: Structure summary