1PUO | pdb_00001puo

Crystal structure of Fel d 1- the major cat allergen

• PDB DOI: https://doi.org/10.2210/pdb1PUO/pdb

• Classification: ALLERGEN
• Organism(s): Felis catus
• Expression System: Escherichia coli
• Mutation(s): No 
• Membrane Protein: Yes  OPM


• Deposited: 2003-06-25 Released: 2003-10-14 
• Deposition Author(s): Kaiser, L., Gronlund, H., Sandalova, T., Ljunggren, H.G., van Hage-Hamsten, M., Achour, A., Schneider, G.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.85 Å
• R-Value Free: 
  0.237 (Depositor), 0.244 (DCC) 
• R-Value Work: 
  0.201 (Depositor) 
• R-Value Observed: 
  0.203 (Depositor) 

Literature

The crystal structure of the major cat allergen Fel d 1, a member of the secretoglobin family.

Kaiser, L., Gronlund, H., Sandalova, T., Ljunggren, H.G., van Hage-Hamsten, M., Achour, A., Schneider, G.

(2003) J Biological Chem 278: 37730-37735

• PubMed: 12851385 
• DOI: https://doi.org/10.1074/jbc.M304740200
• Primary Citation Related Structures: 
  1PUO


• PubMed Abstract: 
  

  The domestic cat (Felis domesticus) is one of the most important causes of allergic asthma worldwide. The dominating cat allergen, Fel d 1, is composed of two heterodimers. Recently, it has been shown that recombinant Fel d 1, consisting of chain 2 and chain 1 fused together without additional linker, has immunological properties indistinguishable from the natural heterodimeric protein. Herein, we report the crystal structure of recombinant monomeric Fel d 1 at 1.85-A resolution, determined by multi-wavelength anomalous diffraction using selenomethionine substituted protein. Fel d 1 is an all-helical protein and consists of eight helices. The two halves of the recombinant Fel d 1 molecule, corresponding to the wild-type Fel d 1 chains, are very similar in three-dimensional structure, despite the lack of significant sequence identity. The structure of the Fel d 1 presents a striking similarity to that of uteroglobin, a steroid-inducible cytokine-like molecule with anti-inflammatory and immunomodulatory properties. An internal, asymmetric cavity is formed in the Fel d 1 that could bind an endogenous ligand. The distribution of residues lining this cavity suggests that such a ligand must be amphipathic. The structure of Fel d 1 displays the localization of three previously defined Fel d 1 IgE epitopes on the surface of the protein. The three-dimensional structure provides a framework for rational design of hypoallergenic mutants aimed for treatment of cat allergy.

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Organizational Affiliation: 
• Department of Medicine, Unit of Clinical Immunology and Allergy, Karolinska Institutet and Hospital L2:04, S-171 76 Stockholm, Sweden.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly 2  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 2 assigned by authors and generated by PISA (software)

Macromolecule Content 

• Total Structure Weight: 38.62 kDa 
• Atom Count: 2,467 
• Modeled Residue Count: 283 
• Deposited Residue Count: 340 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Major allergen I polypeptide, fused chain 2, chain 1	A, B	170	Felis catus	Mutation(s): 0  Gene Names: CH2, CH1 Membrane Entity: Yes
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
UniProt Groups	P30438P30440

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
MPD	C [auth A], D [auth A], E [auth B], F [auth B]	(4S)-2-METHYL-2,4-PENTANEDIOL C6 H14 O2 SVTBMSDMJJWYQN-YFKPBYRVSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.85 Å
• R-Value Free:  0.237 (Depositor), 0.244 (DCC) 
• R-Value Work:  0.201 (Depositor) 
• R-Value Observed: 0.203 (Depositor) 

Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 43.29	α = 90
b = 51.539	β = 95.27
c = 67.725	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
MOSFLM	data reduction
CCP4	data scaling
SOLVE	phasing
RESOLVE	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2003-10-14 
Deposition Author(s): Kaiser, L., Gronlund, H., Sandalova, T., Ljunggren, H.G., van Hage-Hamsten, M., Achour, A., Schneider, G.

Revision History  

• Version 1.0: 2003-10-14
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2017-08-02
  Changes: Data collection, Refinement description, Source and taxonomy
• Version 1.4: 2019-07-03
  Changes: Advisory, Author supporting evidence, Data collection, Derived calculations
• Version 1.5: 2024-10-30
  Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary