1ty0: Difference between revisions
New page: left|200px<br /><applet load="1ty0" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ty0, resolution 1.75Å" /> '''Crystal structure of... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1ty0.gif|left|200px]]<br /><applet load="1ty0" size=" | [[Image:1ty0.gif|left|200px]]<br /><applet load="1ty0" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1ty0, resolution 1.75Å" /> | caption="1ty0, resolution 1.75Å" /> | ||
'''Crystal structure of the streptococcal pyrogenic exotoxin J (SPE-J)'''<br /> | '''Crystal structure of the streptococcal pyrogenic exotoxin J (SPE-J)'''<br /> | ||
==Overview== | ==Overview== | ||
The protein toxins known as superantigens (SAgs), which are expressed | The protein toxins known as superantigens (SAgs), which are expressed primarily by the pathogenic bacteria Staphylococcus aureus and Streptococcus pyogenes, are highly potent immunotoxins with the ability to cause serious human disease. These SAgs share a conserved fold but quite varied activities. In addition to their common role of cross-linking T-cell receptors (TCRs) and major histocompatibility complex class II (MHC-II) molecules, some SAgs can cross-link MHC-II, using diverse mechanisms. The crystal structure of the streptococcal superantigen streptococcal pyrogenic exotoxin J (SPE-J) has been solved at 1.75 A resolution (R = 0.209, R(free) = 0.240), both with and without bound Zn(2+). The structure displays the canonical two-domain SAg fold and a zinc-binding site that is shared by a subset of other SAgs. Most importantly, in concentrated solution and in the crystal, SPE-J forms dimers. These dimers, which are present in two different crystal environments, form via the same face that is used for TCR binding in other SAgs. Site-directed mutagenesis shows that this face is also used for TCR binding SPE-J. We infer that SPE-J cross-links TCR and MHC-II as a monomer but that dimers may form on the antigen-presenting cell surface, cross-linking MHC-II and eliciting intracellular signaling. | ||
==About this Structure== | ==About this Structure== | ||
1TY0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes]. Full crystallographic information is available from [http:// | 1TY0 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TY0 OCA]. | ||
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Streptococcus pyogenes]] | [[Category: Streptococcus pyogenes]] | ||
[[Category: Arcus, V | [[Category: Arcus, V L.]] | ||
[[Category: Baker, E | [[Category: Baker, E N.]] | ||
[[Category: Baker, H | [[Category: Baker, H M.]] | ||
[[Category: Fraser, J | [[Category: Fraser, J D.]] | ||
[[Category: Proft, T.]] | [[Category: Proft, T.]] | ||
[[Category: Webb, P | [[Category: Webb, P D.]] | ||
[[Category: crystal structure]] | [[Category: crystal structure]] | ||
[[Category: dimerization]] | [[Category: dimerization]] | ||
| Line 25: | Line 25: | ||
[[Category: t-cell receptor binding]] | [[Category: t-cell receptor binding]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:18:39 2008'' | ||
Revision as of 16:18, 21 February 2008
|
Crystal structure of the streptococcal pyrogenic exotoxin J (SPE-J)
OverviewOverview
The protein toxins known as superantigens (SAgs), which are expressed primarily by the pathogenic bacteria Staphylococcus aureus and Streptococcus pyogenes, are highly potent immunotoxins with the ability to cause serious human disease. These SAgs share a conserved fold but quite varied activities. In addition to their common role of cross-linking T-cell receptors (TCRs) and major histocompatibility complex class II (MHC-II) molecules, some SAgs can cross-link MHC-II, using diverse mechanisms. The crystal structure of the streptococcal superantigen streptococcal pyrogenic exotoxin J (SPE-J) has been solved at 1.75 A resolution (R = 0.209, R(free) = 0.240), both with and without bound Zn(2+). The structure displays the canonical two-domain SAg fold and a zinc-binding site that is shared by a subset of other SAgs. Most importantly, in concentrated solution and in the crystal, SPE-J forms dimers. These dimers, which are present in two different crystal environments, form via the same face that is used for TCR binding in other SAgs. Site-directed mutagenesis shows that this face is also used for TCR binding SPE-J. We infer that SPE-J cross-links TCR and MHC-II as a monomer but that dimers may form on the antigen-presenting cell surface, cross-linking MHC-II and eliciting intracellular signaling.
About this StructureAbout this Structure
1TY0 is a Single protein structure of sequence from Streptococcus pyogenes. Full crystallographic information is available from OCA.
ReferenceReference
Crystallographic and mutational data show that the streptococcal pyrogenic exotoxin J can use a common binding surface for T-cell receptor binding and dimerization., Baker HM, Proft T, Webb PD, Arcus VL, Fraser JD, Baker EN, J Biol Chem. 2004 Sep 10;279(37):38571-6. Epub 2004 Jul 7. PMID:15247241
Page seeded by OCA on Thu Feb 21 15:18:39 2008