1hqr
From Proteopedia
(New page: 200px<br /> <applet load="1hqr" size="450" color="white" frame="true" align="right" spinBox="true" caption="1hqr, resolution 3.20Å" /> '''CRYSTAL STRUCTURE O...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1hqr.gif|left|200px]]<br /> | + | [[Image:1hqr.gif|left|200px]]<br /><applet load="1hqr" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1hqr" size=" | + | |
caption="1hqr, resolution 3.20Å" /> | caption="1hqr, resolution 3.20Å" /> | ||
'''CRYSTAL STRUCTURE OF A SUPERANTIGEN BOUND TO THE HIGH-AFFINITY, ZINC-DEPENDENT SITE ON MHC CLASS II'''<br /> | '''CRYSTAL STRUCTURE OF A SUPERANTIGEN BOUND TO THE HIGH-AFFINITY, ZINC-DEPENDENT SITE ON MHC CLASS II'''<br /> | ||
==Overview== | ==Overview== | ||
| - | MHC class II molecules possess two binding sites for bacterial | + | 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. |
==Disease== | ==Disease== | ||
| Line 11: | Line 10: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1HQR is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1HQR is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes] with <scene name='pdbligand=ZN:'>ZN</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HQR OCA]. |
==Reference== | ==Reference== | ||
| Line 26: | Line 25: | ||
[[Category: superantigen-mhc class ii complex]] | [[Category: superantigen-mhc class ii complex]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:03:56 2008'' |
Revision as of 11:03, 21 February 2008
|
CRYSTAL STRUCTURE OF A SUPERANTIGEN BOUND TO THE HIGH-AFFINITY, ZINC-DEPENDENT SITE ON MHC CLASS II
Contents |
Overview
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.
Disease
Known diseases associated with this structure: Chronic infections, due to MBL deficiency OMIM:[154545], Diabetes mellitus, gestational, susceptibility to OMIM:[154545], Mannose-binding protein deficiency OMIM:[154545], Meningococcal disease, susceptibility to OMIM:[154545]
About this Structure
1HQR is a Protein complex structure of sequences from Homo sapiens and Streptococcus pyogenes with as ligand. Full crystallographic information is available from OCA.
Reference
Crystal structure of a superantigen bound to the high-affinity, zinc-dependent site on MHC class II., Li Y, Li H, Dimasi N, McCormick JK, Martin R, Schuck P, Schlievert PM, Mariuzza RA, Immunity. 2001 Jan;14(1):93-104. PMID:11163233
Page seeded by OCA on Thu Feb 21 13:03:56 2008
