1ha5: Difference between revisions
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==Overview== | ==Overview== | ||
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 ... | 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 Structure== | ==About this Structure== | ||
1HA5 is a | 1HA5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes] with ZN as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: ZN11. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1HA5 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: zinc binding]] | [[Category: zinc binding]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 12:41:15 2007'' | ||
