Crystal structure of the dog lipocalin allergen Can f 2 and implications for cross-reactivity to the cat allergen Fel d 4

Experimental Data Snapshot

  • Resolution: 1.45 Å
  • R-Value Free: 0.168 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.158 

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Crystal Structure of the Dog Lipocalin Allergen Can f 2: Implications for Cross-reactivity to the Cat Allergen Fel d 4

Madhurantakam, C.Nilsson, O.B.Uchtenhagen, H.Konradsen, J.Saarne, T.Hogbom, E.Sandalova, T.Gronlund, H.Achour, A.

(2010) J Mol Biol 401: 68-83

  • DOI: https://doi.org/10.1016/j.jmb.2010.05.043
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The dog lipocalin allergen Can f 2 is an important cause of allergic sensitization in humans worldwide. Here, the first crystal structure of recombinant rCan f 2 at 1.45 A resolution displays a classical lipocalin fold with a conserved Gly-Xaa-Trp motif, in which Trp19 stabilizes the overall topology of the monomeric rCan f 2. Phe38 and Tyr84 localized on the L1 and L5 loops, respectively, control access to the highly hydrophobic calyx. Although the rCan f 2 calyx is nearly identical with the aero-allergens MUP1, Equ c 1 and A2U from mouse, horse and rat, respectively, no IgE cross-reactivity was found using sera from five mono-sensitized subjects. However, clear IgE cross-reactivity was demonstrated between Can f 2 and the cat allergen Fel d 4, although they share less than 22% sequence identity. This suggests a role for these allergens in co-sensitization between cat- and dog-allergic patients.

  • Organizational Affiliation

    Centre for Infectious Medicine, F59, Department of Medicine Huddinge, Karolinska University Hospital Huddinge, Karolinska Institutet, Stockholm, Sweden.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Minor allergen Can f 2170Canis lupus familiarisMutation(s): 0 
Gene Names: can f 2
Find proteins for O18874 (Canis lupus familiaris)
Explore O18874 
Go to UniProtKB:  O18874
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO18874
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on GOL

Download Ideal Coordinates CCD File 
C3 H8 O3
Experimental Data & Validation

Experimental Data

  • Resolution: 1.45 Å
  • R-Value Free: 0.168 
  • R-Value Work: 0.157 
  • R-Value Observed: 0.158 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.175α = 90
b = 76.898β = 90
c = 64.996γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-05-26
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-11-01
    Changes: Data collection, Database references, Derived calculations, Refinement description