4EL6
Crystal structure of IPSE/alpha-1 from Schistosoma mansoni eggs
Summary for 4EL6
| Entry DOI | 10.2210/pdb4el6/pdb |
| Descriptor | IL-4-inducing protein (2 entities in total) |
| Functional Keywords | beta/gamma-crystallin superfamily, triggers il4 release, ige, signaling protein |
| Biological source | Schistosoma mansoni (Blood fluke) |
| Total number of polymer chains | 1 |
| Total formula weight | 11981.48 |
| Authors | Mayerhofer, H.,Meyer, H.,Tripsianes, K.,Barths, D.,Blindow, S.,Bade, S.,Madl, T.,Frey, A.,Haas, H.,Sattler, M.,Schramm, G.,Mueller-Dieckmann, J. (deposition date: 2012-04-10, release date: 2013-04-10, Last modification date: 2025-05-07) |
| Primary citation | Meyer, N.H.,Mayerhofer, H.,Tripsianes, K.,Blindow, S.,Barths, D.,Mewes, A.,Weimar, T.,Kohli, T.,Bade, S.,Madl, T.,Frey, A.,Haas, H.,Mueller-Dieckmann, J.,Sattler, M.,Schramm, G. A Crystallin Fold in the Interleukin-4-inducing Principle of Schistosoma mansoni Eggs (IPSE/ alpha-1) Mediates IgE Binding for Antigen-independent Basophil Activation. J.Biol.Chem., 290:22111-22126, 2015 Cited by PubMed Abstract: The IL-4-inducing principle from Schistosoma mansoni eggs (IPSE/α-1), the major secretory product of eggs from the parasitic worm S. mansoni, efficiently triggers basophils to release the immunomodulatory key cytokine interleukin-4. Activation by IPSE/α-1 requires the presence of IgE on the basophils, but the detailed molecular mechanism underlying activation is unknown. NMR and crystallographic analysis of IPSEΔNLS, a monomeric IPSE/α-1 mutant, revealed that IPSE/α-1 is a new member of the βγ-crystallin superfamily. We demonstrate that this molecule is a general immunoglobulin-binding factor with highest affinity for IgE. NMR binding studies of IPSEΔNLS with the 180-kDa molecule IgE identified a large positively charged binding surface that includes a flexible loop, which is unique to the IPSE/α-1 crystallin fold. Mutational analysis of amino acids in the binding interface showed that residues contributing to IgE binding are important for IgE-dependent activation of basophils. As IPSE/α-1 is unable to cross-link IgE, we propose that this molecule, by taking advantage of its unique IgE-binding crystallin fold, activates basophils by a novel, cross-linking-independent mechanism. PubMed: 26163514DOI: 10.1074/jbc.M115.675066 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.71 Å) |
Structure validation
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