Download MendeleyThe cross-reactive calcium-binding pollen allergen, Phl p 7, reveals a novel dimer assembly
Verdino, P., Westritschnig, K., Valenta, R., Keller, W.(2002) EMBO J 21: 5007-5016
- PubMed: 12356717
- DOI: https://doi.org/10.1093/emboj/cdf526
- Primary Citation of Related Structures:
1K9U - PubMed Abstract:
The timothy grass pollen allergen Phl p 7 assembles most of the IgE epitopes of a novel family of 2 EF-hand calcium-binding proteins and therefore represents a diagnostic marker allergen and vaccine candidate for immunotherapy. Here we report the first three-dimensional structure of a representative of the 2 EF-hand allergen family, Phl p 7, in the calcium-bound form. The protein occurs as a novel dimer assembly with unique features: in contrast to well known EF-hand proteins such as calmodulin, parvalbumin or the S100 proteins, Phl p 7 adopts an extended conformation. Two protein monomers assemble in a head-to-tail arrangement with domain-swapped EF-hand pairing. The intertwined dimer adopts a barrel-like structure with an extended hydrophobic cavity providing a ligand-binding site. Calcium binding acts as a conformational switch between an open and a closed dimeric form of Phl p 7. These findings are interesting in the context of lipid- and calcium-dependent pollen tube growth. Furthermore, the structure of Phl p 7 allows for the rational development of vaccine strategies for treatment of sensitized allergic patients.
Organizational Affiliation:
Institute of Chemistry, Structural Biology Group, Karl-Franzens-University Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
