Structural highlights
FunctionENTC2_STAAU Staphylococcal enterotoxins cause the intoxication staphylococcal food poisoning syndrome. The illness characterized by high fever, hypotension, diarrhea, shock, and in some cases death. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe previously determined crystal structure of the superantigen staphylococcal enterotoxin C2 (SEC2) showed binding of a single zinc ion located between the N- and C-terminal domains. Here we present the crystal structure of SEC2 determined to 2.0 A resolution in the presence of additional zinc. The structure revealed the presence of a secondary zinc-binding site close to the major histocompatibility complex (MHC)-binding site of the toxin and some 28 A away from the primary zinc-binding site of the toxin found in previous studies. T cell stimulation assays showed that varying the concentration of zinc ions present affected the activity of the toxin and we observed that high zinc concentrations considerably inhibited T cell responses. This indicates that SEC2 may have multiple modes of interaction with the immune system that are dependent on serum zinc levels. The potential role of the secondary zinc-binding site and that of the primary one in the formation of the TCR.SEC2.MHC complex are considered, and the possibility that zinc may regulate the activity of SEC2 as a toxin facilitating different T cell responses is discussed. Identification of a secondary zinc-binding site in staphylococcal enterotoxin C2. Implications for superantigen recognition.,Papageorgiou AC, Baker MD, McLeod JD, Goda SK, Manzotti CN, Sansom DM, Tranter HS, Acharya KR J Biol Chem. 2004 Jan 9;279(2):1297-303. Epub 2003 Oct 14. PMID:14559915[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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