8EPU | pdb_00008epu

1.6 A crystal structure of the lipocalin dog allergen Can f 1 with the C118S mutation


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 
    0.230 (Depositor), 0.228 (DCC) 
  • R-Value Work: 
    0.211 (Depositor), 0.211 (DCC) 
  • R-Value Observed: 
    0.212 (Depositor) 

Starting Model: in silico
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wwPDB Validation 3D Report Full Report

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This is version 1.2 of the entry. See complete history

Literature

Structural and ligand binding analysis of the pet allergens Can f 1 and Fel d 7.

Min, J.Foo, A.C.Y.Gabel, S.A.Perera, L.DeRose, E.F.Pomes, A.Pedersen, L.C.Mueller, G.A.

(2023) Front Allergy 4: 1133412-1133412

  • DOI: https://doi.org/10.3389/falgy.2023.1133412
  • Primary Citation Related Structures: 
    8EPU, 8EPV

  • PubMed Abstract: 

    Pet lipocalins are respiratory allergens with a central hydrophobic ligand-binding cavity called a calyx. Molecules carried in the calyx by allergens are suggested to influence allergenicity, but little is known about the native ligands. To provide more information on prospective ligands, we report crystal structures, NMR, molecular dynamics, and florescence studies of a dog lipocalin allergen Can f 1 and its closely related (and cross-reactive) cat allergen Fel d 7. Structural comparisons with reported lipocalins revealed that Can f 1 and Fel d 7 calyxes are open and positively charged while other dog lipocalin allergens are closed and negatively charged. We screened fatty acids as surrogate ligands, and found that Can f 1 and Fel d 7 bind multiple ligands with preferences for palmitic acid (16:0) among saturated fatty acids and oleic acid (18:1 cis-9) among unsaturated ones. NMR analysis of methyl probes reveals that conformational changes occur upon binding of pinolenic acid inside the calyx. Molecular dynamics simulation shows that the carboxylic group of fatty acids shuttles between two positively charged amino acids inside the Can f 1 and Fel d 7 calyx. Consistent with simulations, the stoichiometry of oleic acid-binding is 2:1 (fatty acid: protein) for Can f 1 and Fel d 7. The results provide valuable insights into the determinants of selectivity and candidate ligands for pet lipocalin allergens Can f 1 and Fel d 7.


  • Organizational Affiliation
    • Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Durham, NC, United States.

Macromolecule Content 

  • Total Structure Weight: 16.57 kDa 
  • Atom Count: 1,170 
  • Modeled Residue Count: 145 
  • Deposited Residue Count: 149 
  • Unique protein chains: 1

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
Major allergen Can f 1149Canis lupus familiarisMutation(s): 1 
UniProt
Find proteins for O18873 (Canis lupus familiaris)
Explore O18873 
Go to UniProtKB:  O18873
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO18873
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free:  0.230 (Depositor), 0.228 (DCC) 
  • R-Value Work:  0.211 (Depositor), 0.211 (DCC) 
  • R-Value Observed: 0.212 (Depositor) 
Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.214α = 90
b = 36.512β = 100.8
c = 57.973γ = 90
Software Package:
Software NamePurpose
SERGUIdata collection
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

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Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of Environmental Health Sciences (NIH/NIEHS)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2023-04-05
    Type: Initial release
  • Version 1.1: 2024-04-03
    Changes: Data collection, Refinement description
  • Version 1.2: 2024-10-16
    Changes: Structure summary