1ha5: Difference between revisions
No edit summary |
No edit summary |
||
| Line 26: | Line 26: | ||
[[Category: zinc binding]] | [[Category: zinc binding]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 16:33:36 2007'' | ||
Revision as of 17:28, 5 November 2007
|
STRUCTURAL FEATURES OF A ZINC-BINDING SITE IN THE SUPERANTIGEN STREPTOCOCCAL PYROGENIC EXOTOXIN A (SPEA1): IMPLICATIONS FOR MHC CLASS II RECOGNITION.
OverviewOverview
Streptococcal pyrogenic exotoxin A (SpeA) is a superantigen produced by, Streptococcus pyogenes and is associated with severe infections, characterized by rash, hypotension, multiorgan failure and a high, mortality rate. In this study, an allelic form of this toxin, SpeA1, was, crystallized with four molecules in the crystallographic asymmetric unit, and its crystal structure was determined at 2.6 A resolution. The, crystallographic R-factor was 19.4% (33 497 reflections) for 7031 protein, atoms and 88 water molecules. The overall structure of SpeA1 is, considerably similar to that of other prototype microbial superantigens, either of staphylococcal or streptococcal origin, but has greatest, similarity to staphylococcal enterotoxin C (SEC). Based on structural and, mutagenesis data, we have mapped several important residues on the toxin, molecule, which are involved in the recognition of major, histocompatibility complex (MHC) class II molecules and T-cell receptors., Also, the toxin appears to possess a potential zinc-binding site which may, have implications in binding to particular MHC class II molecules., Finally, we propose models for SpeA1-MHC class II and SpeA1-T-cell, receptor association and the relevance of this phenomenon to the, superantigenic action of this toxin is considered.
About this StructureAbout this Structure
1HA5 is a Single protein structure of sequence from Streptococcus pyogenes with ZN as ligand. Structure known Active Site: ZN11. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for the recognition of superantigen streptococcal pyrogenic exotoxin A (SpeA1) by MHC class II molecules and T-cell receptors., Papageorgiou AC, Collins CM, Gutman DM, Kline JB, O'Brien SM, Tranter HS, Acharya KR, EMBO J. 1999 Jan 4;18(1):9-21. PMID:9878045
Page seeded by OCA on Mon Nov 5 16:33:36 2007