Summary
PDB 2OJE deposited: 2007-01-12 modified: 2009-02-24
Title Mycoplasma arthritidis-derived mitogen complexed with class II MHC molecule HLA-DR1/HA complex in the presence of EDTA
Authors Eisele, L., Guo, Y., Li, H., Li, Z., Mourad, W., Zhao, Y.
Method X-RAY DIFFRACTION
Structure factors resolution 3.0 rfactor 0.211 rfree 0.261
DPI 1.37 theoretical min: 0.58
Citations

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.

J Biol Chem. 2007 Mar 2;282(9):5991-6000. Epub 2006 Dec 13.

Cross References
Database source Identifier Description
PubMed 17166841 JBCHA3
Biomolecule Structure Assembly Serial Assembly Type Conformational State Chains Ligands Atoms
2OJE/1 2OJE 1 tetramer 0 4 2 4669
2OJE/2 2OJE 2 tetramer 0 4 2 4738
2OJE/3 2OJE 3 hexadecamer 0 16 8 18814