1jck
From Proteopedia
(New page: 200px<br /><applet load="1jck" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jck, resolution 3.5Å" /> '''T-CELL RECEPTOR BETA ...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1jck.gif|left|200px]]<br /><applet load="1jck" size=" | + | [[Image:1jck.gif|left|200px]]<br /><applet load="1jck" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1jck, resolution 3.5Å" /> | caption="1jck, resolution 3.5Å" /> | ||
'''T-CELL RECEPTOR BETA CHAIN COMPLEXED WITH SEC3 SUPERANTIGEN'''<br /> | '''T-CELL RECEPTOR BETA CHAIN COMPLEXED WITH SEC3 SUPERANTIGEN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Superantigens (SAgs) are viral or bacterial proteins that act as potent | + | Superantigens (SAgs) are viral or bacterial proteins that act as potent T-cell stimulants and have been implicated in a number of human diseases, including toxic shock syndrome, diabetes mellitus and multiple sclerosis. The interaction of SAgs with the T-cell receptor (TCR) and major histocompatibility complex (MHC) proteins results in the stimulation of a disproportionately large fraction of the T-cell population. We report here the crystal structures of the beta-chain of a TCR complexed with the Staphylococcus aureus enterotoxins C2 and C3 (SEC2, SEC3). These enterotoxins, which cause both toxic shock and food poisoning, bind in an identical way to the TCR beta-chain. The complementarity-determining region 2 (CDR2) of the beta-chain and, to lesser extents, CDR1 and hypervariable region 4 (HV4), bind in a cleft between the two domains of the SAgs. Thus, there is considerable overlap between the SAg-binding site and the peptide/MHC-binding sites of the TCR. A model of a TCR-SAg-MHC complex constructed from the crystal structures of (1) the beta-chain-SEC3 complex, (2) a complex between staphylococcal enterotoxin B (SEB) and an MHC molecule, and (3) a TCR V(alpha) domain, reveals that the SAg acts as a wedge between the TCR and MHC to displace the antigenic peptide away from the TCR combining site. In this way, the SAg is able to circumvent the normal mechanism for T-cell activation by specific peptide/MHC complexes. |
==About this Structure== | ==About this Structure== | ||
| - | 1JCK is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] and [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http:// | + | 1JCK is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus] and [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JCK OCA]. |
==Reference== | ==Reference== | ||
| Line 14: | Line 14: | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
| - | [[Category: Fields, B | + | [[Category: Fields, B A.]] |
| - | [[Category: Mariuzza, R | + | [[Category: Mariuzza, R A.]] |
[[Category: complex (toxin/receptor)]] | [[Category: complex (toxin/receptor)]] | ||
[[Category: enterotoxin]] | [[Category: enterotoxin]] | ||
| Line 26: | Line 26: | ||
[[Category: transmembrane]] | [[Category: transmembrane]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:21:13 2008'' |
Revision as of 11:21, 21 February 2008
|
T-CELL RECEPTOR BETA CHAIN COMPLEXED WITH SEC3 SUPERANTIGEN
Overview
Superantigens (SAgs) are viral or bacterial proteins that act as potent T-cell stimulants and have been implicated in a number of human diseases, including toxic shock syndrome, diabetes mellitus and multiple sclerosis. The interaction of SAgs with the T-cell receptor (TCR) and major histocompatibility complex (MHC) proteins results in the stimulation of a disproportionately large fraction of the T-cell population. We report here the crystal structures of the beta-chain of a TCR complexed with the Staphylococcus aureus enterotoxins C2 and C3 (SEC2, SEC3). These enterotoxins, which cause both toxic shock and food poisoning, bind in an identical way to the TCR beta-chain. The complementarity-determining region 2 (CDR2) of the beta-chain and, to lesser extents, CDR1 and hypervariable region 4 (HV4), bind in a cleft between the two domains of the SAgs. Thus, there is considerable overlap between the SAg-binding site and the peptide/MHC-binding sites of the TCR. A model of a TCR-SAg-MHC complex constructed from the crystal structures of (1) the beta-chain-SEC3 complex, (2) a complex between staphylococcal enterotoxin B (SEB) and an MHC molecule, and (3) a TCR V(alpha) domain, reveals that the SAg acts as a wedge between the TCR and MHC to displace the antigenic peptide away from the TCR combining site. In this way, the SAg is able to circumvent the normal mechanism for T-cell activation by specific peptide/MHC complexes.
About this Structure
1JCK is a Protein complex structure of sequences from Mus musculus and Staphylococcus aureus. Full crystallographic information is available from OCA.
Reference
Crystal structure of a T-cell receptor beta-chain complexed with a superantigen., Fields BA, Malchiodi EL, Li H, Ysern X, Stauffacher CV, Schlievert PM, Karjalainen K, Mariuzza RA, Nature. 1996 Nov 14;384(6605):188-92. PMID:8906797
Page seeded by OCA on Thu Feb 21 13:21:13 2008
