1UNS

IDENTIFICATION OF A SECONDARY ZINC-BINDING SITE IN STAPHYLOCOCCAL ENTEROTOXIN C2: IMPLICATIONS FOR SUPERANTIGEN RECOGNITION

DOI: 10.2210/pdb1UNS/pdb

Classification: TOXIN
Organism(s): Staphylococcus aureus
Mutation(s): No

Deposited: 2003-09-15 Released: 2003-11-13
Deposition Author(s): Papageorgiou, A.C., Baker, M.D., McLeod, J.D., Goda, S., Sansom, D.M., Tranter, H.S., Acharya, K.R.

Experimental Data Snapshot

Method: X-RAY DIFFRACTION
Resolution: 2.00 Å
R-Value Free: 0.225
R-Value Work: 0.198
R-Value Observed: 0.198

wwPDB Validation 3D Report Full Report

This is version 1.2 of the entry. See complete history.

Literature

Identification of a Secondary Zinc-Binding Site in Staphylococcal Enterotoxin C2: Implications for Superantigen Recognition

Papageorgiou, 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 Search on PubMed
DOI: 10.1074/jbc.M307333200
Primary Citation of Related Structures:
1UNS

PubMed Abstract:

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.

Related Citations:

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

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

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

Organizational Affiliation:

Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.

Macromolecules

Find similar proteins by:

(by identity cutoff) | Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ENTEROTOXIN TYPE C-2	A	239	Staphylococcus aureus	Mutation(s): 0 Gene Names: entC2
Find proteins for P34071 (Staphylococcus aureus) Explore P34071 Go to UniProtKB: P34071
Protein Feature View Expand
Reference Sequence

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
ZN Query on ZN Download Ideal Coordinates CCD File SDF format, chain B [A] SDF format, chain C [A] MOL2 format, chain B [A] MOL2 format, chain C [A]	A	ZINC ION Zn PTFCDOFLOPIGGS-UHFFFAOYSA-N		Ligand Interaction