1ha5
Structural features of a zinc-binding site in the superantigen streptococcal pyrogenic exotoxin A (SpeA1): implications for MHC class II recognition.Structural features of a zinc-binding site in the superantigen streptococcal pyrogenic exotoxin A (SpeA1): implications for MHC class II recognition.
Structural highlights
FunctionSPEA_STRPY Causative agent of the symptoms associated with scarlet fever, have been associated with streptococcal toxic shock-like disease and may play a role in the early events of rheumatic fever. Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedStreptococcal pyrogenic exotoxin A (SpeA) is produced by Streptococcus pyogenes, and has been associated with severe infections such as scarlet fever and Streptococcal Toxic Shock Syndrome (STSS). In this study, the crystal structure of SpeA1 (the product of speA allele 1) in the presence of 2.5 mM zinc was determined at 2.8 A resolution. The protein crystallizes in the orthorhombic space group P2(1)2(1)2, with four molecules in the crystallographic asymmetric unit. The final structure has a crystallographic R-factor of 21.4% for 7,031 protein atoms, 143 water molecules, and 4 zinc atoms (one zinc atom per molecule). Four protein ligands-Glu 33, Asp 77, His 106, and His 110-form a zinc binding site that is similar to the one observed in a related superantigen, staphylococcoal enterotoxin C2. Mutant toxin forms substituting Ala for each of the zinc binding residues were generated. The affinity of these mutants for zinc ion confirms the composition of this metal binding site. The implications of zinc binding to SpeA1 for MHC class II recognition are explored using a molecular modeling approach. The results indicate that, despite their common overall architecture, superantigens appear to have multiple ways of complex formation with MHC class II molecules. Structural features of a zinc binding site in the superantigen strepococcal pyrogenic exotoxin A (SpeA1): implications for MHC class II recognition.,Baker M, Gutman DM, Papageorgiou AC, Collins CM, Acharya KR Protein Sci. 2001 Jun;10(6):1268-73. PMID:11369867[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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