spacer Mycoplasma arthritidis-derived mitogen complexed with class II MHC molecule HLA-DR1/HA complex in the presence of EDTA
Primary citation
Title Zinc induces dimerization of the class II major histocompatibility complex molecule that leads to cooperative binding to a superantigen.
Authors Li, H.search; Zhao, Y.search; Guo, Y.search; Li, Z.search; Eisele, L.search; Mourad, W.search
Journal J.BIOL.CHEM.search vol:282, pag:5991-6000 (2007), Identifiers: PubMed ID (17166841)search DOI (10.1074/jbc.M608482200)
Abstract Dimerization of class II major histocompatibility complex (MHC) plays an important role in the MHC biological function. Mycoplasma arthritidis-derived mitogen (MAM) is a superantigen that can activate large fractions of T cells bearing specific T cell receptor Vbeta elements. Here we have used structural, sedimentation, and surface plasmon resonance detection approaches to investigate the molecular interactions between MAM and the class II MHC molecule HLA-DR1 in the context of a hemagglutinin peptide-(306-318) (HA). Our results revealed that zinc ion can efficiently induce the dimerization of the HLA-DR1/HA complex. Because the crystal structure of the MAM/HLA-DR1/hemagglutinin complex in the presence of EDTA is nearly identical to the structure of the complex crystallized in the presence of zinc ion, Zn(2+) is evidently not directly involved in the binding between MAM and HLA-DR1. Sedimentation and surface plasmon resonance studies further revealed that MAM binds the HLA-DR1/HA complex with high affinity in a 1:1 stoichiometry, in the absence of Zn(2+). However, in the presence of Zn(2+), a dimerized MAM/HLA-DR1/HA complex can arise through the Zn(2+)-induced DR1 dimer. In the presence of Zn(2+), cooperative binding of MAM to the DR1 dimer was also observed.
MeSH terms Antigenssearch, Bacterialsearch, Crystallographysearch, X-Raysearch, Dimerizationsearch, HLA-DR1 Antigensearch, Hemagglutininssearch, Histocompatibility Antigens Class IIsearch, Humanssearch, Multiprotein Complexessearch, Mycoplasma arthritidissearch, Protein Bindingsearch, Protein Conformationsearch, Superantigenssearch, Zincsearch
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