2ici
From Proteopedia
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|PDB= 2ici |SIZE=350|CAPTION= <scene name='initialview01'>2ici</scene>, resolution 1.560Å | |PDB= 2ici |SIZE=350|CAPTION= <scene name='initialview01'>2ici</scene>, resolution 1.560Å | ||
|SITE= | |SITE= | ||
| - | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM ION'>MG</scene> | + | |LIGAND= <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene> |
|ACTIVITY= | |ACTIVITY= | ||
|GENE= speI ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1314 Streptococcus pyogenes]) | |GENE= speI ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1314 Streptococcus pyogenes]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2ici FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ici OCA], [http://www.ebi.ac.uk/pdbsum/2ici PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=2ici RCSB]</span> | ||
}} | }} | ||
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[[Category: Sundberg, E J.]] | [[Category: Sundberg, E J.]] | ||
[[Category: Varma, A K.]] | [[Category: Varma, A K.]] | ||
| - | [[Category: MG]] | ||
[[Category: streptococcal superantigen spei]] | [[Category: streptococcal superantigen spei]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Mar 31 03:42:25 2008'' |
Revision as of 00:42, 31 March 2008
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| , resolution 1.560Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Gene: | speI (Streptococcus pyogenes) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of Streptococcal Pyrogenic Exotoxin I
Overview
Superantigens (SAgs) are potent microbial toxins that bind simultaneously to T cell receptors (TCRs) and class II major histocompatibility complex molecules, resulting in the activation and expansion of large T cell subsets and the onset of numerous human diseases. Within the bacterial SAg family, streptococcal pyrogenic exotoxin I (SpeI) has been classified as belonging to the group V SAg subclass, which are characterized by a unique, relatively conserved approximately 15 amino acid extension (amino acid residues 154 to 170 in SpeI; herein referred to as the alpha3-beta8 loop), absent in SAg groups I through IV. Here, we report the crystal structure of SpeI at 1.56 A resolution. Although the alpha3-beta8 loop in SpeI is several residues shorter than that of another group V SAg, staphylococcal enterotoxin serotype I, the C-terminal portions of these loops, which are located adjacent to the putative TCR binding site, are structurally similar. Mutagenesis and subsequent functional analysis of SpeI indicates that TCR beta-chains are likely engaged in a similar general orientation as other characterized SAgs. We show, however, that the alpha3-beta8 loop length, and the presence of key glycine residues, are necessary for optimal activation of T cells. Based on Vbeta-skewing analysis of human T cells activated with SpeI and structural models, we propose that the alpha3-beta8 loop is positioned to form productive intermolecular contacts with the TCR beta-chain, likely in framework region 3, and that these contacts are required for optimal TCR recognition by SpeI, and likely all other group V SAgs.
About this Structure
2ICI is a Single protein structure of sequence from Streptococcus pyogenes. Full crystallographic information is available from OCA.
Reference
Crystal structure of the streptococcal superantigen SpeI and functional role of a novel loop domain in T cell activation by group V superantigens., Brouillard JN, Gunther S, Varma AK, Gryski I, Herfst CA, Rahman AK, Leung DY, Schlievert PM, Madrenas J, Sundberg EJ, McCormick JK, J Mol Biol. 2007 Apr 6;367(4):925-34. Epub 2007 Jan 12. PMID:17303163
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