3seb
From Proteopedia
(New page: 200px<br /><applet load="3seb" size="450" color="white" frame="true" align="right" spinBox="true" caption="3seb, resolution 1.48Å" /> '''STAPHYLOCOCCAL ENTER...) |
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| - | [[Image:3seb.gif|left|200px]]<br /><applet load="3seb" size=" | + | [[Image:3seb.gif|left|200px]]<br /><applet load="3seb" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="3seb, resolution 1.48Å" /> | caption="3seb, resolution 1.48Å" /> | ||
'''STAPHYLOCOCCAL ENTEROTOXIN B'''<br /> | '''STAPHYLOCOCCAL ENTEROTOXIN B'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Staphylococcal enterotoxin B is a member of a family of toxins known as | + | Staphylococcal enterotoxin B is a member of a family of toxins known as superantigens that activate a large number of T-cells (up to 20%) by cross-linking MHC class II molecules with T-cell receptors in a Vbeta-restricted fashion. The crystal structure of staphylococcal enterotoxin B presented here has been determined at 1.5 A resolution, the highest resolution so far for a superantigen. The final model contains 1948 protein atoms and 177 water molecules and has excellent geometry with root-mean-square (rms) deviation of 0.007 A and 1.73 degrees in bond lengths and bond angles, respectively. The overall fold is similar to that of other microbial superantigens, but as it lacks the zinc-binding site found in other members of this family, such as staphylococcal enterotoxin A, C2 and D, this enterotoxin possesses only one MHC class II binding site. Comparison of the crystal structure of free SEB and in complex with an MHC class II molecule revealed no major changes in the MHC-binding site upon complex formation. However, a number of water molecules found in the free SEB may be displaced in the complex or contribute further to its stability. Detailed analysis of the TcR-binding site of SEB, SEA and SEC2 shows significant differences which may account for the ability of each superantigen to bind specific Vbeta sequences. |
==About this Structure== | ==About this Structure== | ||
| - | 3SEB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http:// | + | 3SEB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3SEB OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Staphylococcus aureus]] | [[Category: Staphylococcus aureus]] | ||
| - | [[Category: Acharya, K | + | [[Category: Acharya, K R.]] |
| - | [[Category: Papageorgiou, A | + | [[Category: Papageorgiou, A C.]] |
[[Category: enterotoxin]] | [[Category: enterotoxin]] | ||
[[Category: superantigen]] | [[Category: superantigen]] | ||
[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:11:19 2008'' |
Revision as of 17:11, 21 February 2008
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STAPHYLOCOCCAL ENTEROTOXIN B
Overview
Staphylococcal enterotoxin B is a member of a family of toxins known as superantigens that activate a large number of T-cells (up to 20%) by cross-linking MHC class II molecules with T-cell receptors in a Vbeta-restricted fashion. The crystal structure of staphylococcal enterotoxin B presented here has been determined at 1.5 A resolution, the highest resolution so far for a superantigen. The final model contains 1948 protein atoms and 177 water molecules and has excellent geometry with root-mean-square (rms) deviation of 0.007 A and 1.73 degrees in bond lengths and bond angles, respectively. The overall fold is similar to that of other microbial superantigens, but as it lacks the zinc-binding site found in other members of this family, such as staphylococcal enterotoxin A, C2 and D, this enterotoxin possesses only one MHC class II binding site. Comparison of the crystal structure of free SEB and in complex with an MHC class II molecule revealed no major changes in the MHC-binding site upon complex formation. However, a number of water molecules found in the free SEB may be displaced in the complex or contribute further to its stability. Detailed analysis of the TcR-binding site of SEB, SEA and SEC2 shows significant differences which may account for the ability of each superantigen to bind specific Vbeta sequences.
About this Structure
3SEB is a Single protein structure of sequence from Staphylococcus aureus. Full crystallographic information is available from OCA.
Reference
Crystal structure of microbial superantigen staphylococcal enterotoxin B at 1.5 A resolution: implications for superantigen recognition by MHC class II molecules and T-cell receptors., Papageorgiou AC, Tranter HS, Acharya KR, J Mol Biol. 1998 Mar 20;277(1):61-79. PMID:9514739
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