4IGY

Crystal structure of kirola (Act d 11) - triclinic form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.92 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.212 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structural and bioinformatic analysis of the kiwifruit allergen Act d 11, a member of the family of ripening-related proteins.

Chruszcz, M.Ciardiello, M.A.Osinski, T.Majorek, K.A.Giangrieco, I.Font, J.Breiteneder, H.Thalassinos, K.Minor, W.

(2013) Mol Immunol 56: 794-803

  • DOI: https://doi.org/10.1016/j.molimm.2013.07.004
  • Primary Citation of Related Structures:  
    4IGV, 4IGW, 4IGX, 4IGY, 4IH0, 4IH2, 4IHR

  • PubMed Abstract: 

    The allergen Act d 11, also known as kirola, is a 17 kDa protein expressed in large amounts in ripe green and yellow-fleshed kiwifruit. Ten percent of all kiwifruit-allergic individuals produce IgE specific for the protein. Using X-ray crystallography, we determined the first three-dimensional structures of Act d 11, produced from both recombinant expression in Escherichia coli and from the natural source (kiwifruit). While Act d 11 is immunologically correlated with the birch pollen allergen Bet v 1 and other members of the pathogenesis-related protein family 10 (PR-10), it has low sequence similarity to PR-10 proteins. By sequence Act d 11 appears instead to belong to the major latex/ripening-related (MLP/RRP) family, but analysis of the crystal structures shows that Act d 11 has a fold very similar to that of Bet v 1 and other PR-10 related allergens regardless of the low sequence identity. The structures of both the natural and recombinant protein include an unidentified ligand, which is relatively small (about 250 Da by mass spectrometry experiments) and most likely contains an aromatic ring. The ligand-binding cavity in Act d 11 is also significantly smaller than those in PR-10 proteins. The binding of the ligand, which we were not able to unambiguously identify, results in conformational changes in the protein that may have physiological and immunological implications. Interestingly, the residue corresponding to Glu45 in Bet v 1 (Glu46), which is important for IgE binding to the birch pollen allergen, is conserved in Act d 11, even though it is not in other allergens with significantly higher sequence identity to Bet v 1. We suggest that the so-called Gly-rich loop (or P-loop), which is conserved in all PR-10 allergens, may be responsible for IgE cross-reactivity between Bet v 1 and Act d 11.


  • Organizational Affiliation

    Department of Chemistry and Biochemistry, University of South Carolina, 631 Sumter Street, Columbia, SC 29208, USA; Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA. Electronic address: chruszcz@mailbox.sc.edu.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Kirola
A, B, C, D
150Actinidia deliciosaMutation(s): 0 
UniProt
Find proteins for P85524 (Actinidia deliciosa)
Explore P85524 
Go to UniProtKB:  P85524
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP85524
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.92 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.212 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 56.144α = 66.34
b = 56.094β = 85.37
c = 64.949γ = 65.24
Software Package:
Software NamePurpose
HKL-3000data collection
HKL-3000phasing
MOLREPphasing
REFMACrefinement
HKL-3000data reduction
HKL-3000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-09-04
    Type: Initial release
  • Version 1.1: 2022-04-13
    Changes: Database references, Derived calculations, Structure summary
  • Version 1.2: 2023-09-20
    Changes: Data collection, Refinement description