1HQR

CRYSTAL STRUCTURE OF A SUPERANTIGEN BOUND TO THE HIGH-AFFINITY, ZINC-DEPENDENT SITE ON MHC CLASS II

Summary for 1HQR

• Entry DOI: 10.2210/pdb1hqr/pdb
• Descriptor: HLA-DR ALPHA CHAIN, HLA-DR BETA CHAIN, MYELIN BASIC PROTEIN, ... (5 entities in total)
• Functional Keywords: superantigen-mhc class ii complex, immune system
• Biological source: Homo sapiens (human); More
• Cellular location: Cell membrane; Single-pass type I membrane protein: P01903; Myelin membrane; Peripheral membrane protein; Cytoplasmic side: P02686
• Total number of polymer chains: 4
• Total formula weight: 69324.94

Authors

Li, Y.,Li, H.,Dimasi, N.,Schlievert, P.,Mariuzza, R. (deposition date: 2000-12-19, release date: 2001-01-03, Last modification date: 2024-11-13)

Primary citation

Li, Y.,Li, H.,Dimasi, N.,McCormick, J.K.,Martin, R.,Schuck, P.,Schlievert, P.M.,Mariuzza, R.A.
Crystal structure of a superantigen bound to the high-affinity, zinc-dependent site on MHC class II.
Immunity, 14:93-104, 2001

PubMed Abstract: MHC class II molecules possess two binding sites for bacterial superantigens (SAGs): a low-affinity site on the alpha chain and a high-affinity, zinc-dependent site on the beta chain. Only the former has been defined crystallographically. We report the structure of streptococcal pyrogenic exotoxin C (SPE-C) complexed with HLA-DR2a (DRA*0101, DRB5*0101) bearing a self-peptide from myelin basic protein (MBP). SPE-C binds the beta chain through a zinc bridge that links the SAG and class II molecules. Surprisingly, SPE-C also makes extensive contacts with the MBP peptide, such that peptide accounts for one third of the surface area of the MHC molecule buried in the complex, similar to TCR-peptide/MHC complexes. Thus, SPE-C may optimize T cell responses by mimicking the peptide dependence of conventional antigen presentation and recognition.

PubMed: 11163233
DOI: 10.1016/S1074-7613(01)00092-9

Experimental method

X-RAY DIFFRACTION (3.2 Å)