Identification of a Secondary Zinc-Binding Site in Staphylococcal Enterotoxin C2: Implications for Superantigen RecognitionPapageorgiou, A.C., Baker, M.D., Mcleod, J.D., Goda, S., Manzotti, C.N., Sanson, D.M., Tranter, H.S., Acharya, K.R.
(2004) J.Biol.Chem. 279: 1297
- PubMed: 14559915
- DOI: 10.1074/jbc.M307333200
- PubMed Abstract:
- Crystallization and Preliminary X-Ray Analysis of a Microbial Superantigen Staphylococcal Enterotoxin C2
Passalacqua, E.F.,Brehm, R.D.,Acharya, K.R.,Tranter, H.S.
(1993) J.Mol.Biol. 233: 170
- Molecular Topology is Important for the Function of Staphylococcal Superantigens
Tranter, H.,Brehm, R.D.,Acharya, K.R.
(1995) Bacterial Superantigens: Structure, Function and Therapeutic Potential --: 5
- Structural Basis of Superantigen Action Inferred from Crystal Structure of Toxic-Shock Syndrome Toxin-1
Acharya, K.R.,Passalacqua, E.F.,Jones, E.Y.,Harlos, K.,Stuart, D.I.,Brehm, R.D.,Tranter, H.S.
(1994) Nature 367: 94
- Structure of the Superantigen Enterotoxin C2 from Staphylococcus Aureus Reveals a Zinc-Binding Site
Papageorgiou, A.C.,Acharya, K.R.,Shapiro, R.,Passalacqua, E.F.,Brehm, R.D.,Tranter, H.S.
(1995) Structure 3: 769
The 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 ...
The 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.
Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.