1bxt
|
STREPTOCOCCAL SUPERANTIGEN (SSA) FROM STREPTOCOCCUS PYOGENES
OverviewOverview
Streptococcal superantigen (SSA) is a 28,000 Mr toxin originally isolated, from a pathogenic strain of Streptococcus pyogenes that has 60% sequence, identity with staphylococcal enterotoxin B (SEB). SSA and SEB, however, do, not compete for binding on the surfaces of cells expressing MHC class II, molecules. This behavior had been ascribed to SSA and SEB binding to, distinct sites on, or different subsets of, HLA-DR molecules. Here we, demonstrate that SSA binds predominantly to HLA-DQ, rather than to HLA-DR, molecules, and present the crystal structure of SSA at 1.85 A resolution., These data provide a structural basis for interpreting the interaction of, SSA with HLA-DQ molecules as well as a foundation for understanding, bacterial superantigen affinities for distinct MHC isotypes.
About this StructureAbout this Structure
1BXT is a Single protein structure of sequence from Streptococcus pyogenes. Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for HLA-DQ binding by the streptococcal superantigen SSA., Sundberg E, Jardetzky TS, Nat Struct Biol. 1999 Feb;6(2):123-9. PMID:10048922
Page seeded by OCA on Sun Nov 25 00:45:57 2007