4RGM

Structure of Staphylococcal Enterotoxin B bound to the neutralizing antibody 20B1

DOI: 10.2210/pdb4RGM/pdb

Classification: TOXIN/IMMUNE SYSTEM
Organism(s): Staphylococcus aureus, Mus musculus
Expression System: Escherichia coli BL21(DE3)
Mutation(s): No

Deposited: 2014-09-30 Released: 2015-01-21
Deposition Author(s): Franklin, M.C., Dutta, K., Varshney, A.K., Goger, M.J., Fries, B.C.

Experimental Data Snapshot

Method: X-RAY DIFFRACTION
Resolution: 2.69 Å
R-Value Free: 0.277
R-Value Work: 0.225
R-Value Observed: 0.228

wwPDB Validation 3D Report Full Report

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

Literature

Mechanisms mediating enhanced neutralization efficacy of staphylococcal enterotoxin B by combinations of monoclonal antibodies.

Dutta, K., Varshney, A.K., Franklin, M.C., Goger, M., Wang, X., Fries, B.C.

(2015) J Biol Chem 290: 6715-6730

PubMed: 25572397 Search on PubMedSearch on PubMed Central
DOI: 10.1074/jbc.M114.630715
Primary Citation of Related Structures:
4RGM, 4RGN, 4RGO

PubMed Abstract:

Staphylococcal enterotoxin B (SEB) is a superantigen that cross-links the major histocompatibility complex class II and specific V-β chains of the T-cell receptor, thus forming a ternary complex. Developing neutralizing mAb to disrupt the ternary complex and abrogate the resulting toxicity is a major therapeutic challenge because SEB is effective at very low concentrations. We show that combining two SEB-specific mAbs enhances their efficacy, even though one of the two mAbs by itself has no effect on neutralization. Crystallography was employed for fine-mapping conformational epitopes in binary and ternary complexes between SEB and Fab fragments. NMR spectroscopy was used to validate and identify subtle allosteric changes induced by mAbs binding to SEB. The mapping of epitopes established that a combination of different mAbs can enhance efficacy of mAb-mediated protection from SEB induced lethal shock by two different mechanisms: one mAb mixture promoted clearance of the toxin both in vitro and in vivo by FcR-mediated cross-linking and clearance, whereas the other mAb mixture induced subtle allosteric conformational changes in SEB that perturbed formation of the SEB·T-cell receptor·major histocompatibility complex class II trimer. Finally structural information accurately predicted mAb binding to other superantigens that share conformational epitopes with SEB. Fine mapping of conformational epitopes is a powerful tool to establish the mechanism and optimize the action of synergistic mAb combinations.

Related Citations:

Generation, characterization, and epitope mapping of neutralizing and protective monoclonal antibodies against staphylococcal enterotoxin B-induced lethal shock.
Varshney, A.K., Wang, X., Cook, E., Dutta, K., Scharff, M.D., Goger, M.J., Fries, B.C.
(2011) J Biol Chem 286: 9737

Organizational Affiliation:

the Department of Medicine and Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11790, and the Department of Medicine, Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York 10461 Bettina.Fries@stonybrookmedicine.edu.

Macromolecules

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(by identity cutoff) | Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Enterotoxin type B	A, S	245	Staphylococcus aureus	Mutation(s): 0 Gene Names: entB
Find proteins for P01552 (Staphylococcus aureus) Explore P01552 Go to UniProtKB: P01552
Protein Feature View Expand
Reference Sequence

Find similar proteins by:

(by identity cutoff) | Structure

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
20B1 light chain	B, L	214	Mus musculus	Mutation(s): 0
Protein Feature View Expand
Reference Sequence

Find similar proteins by:

(by identity cutoff) | Structure

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
20B1 heavy chain	C, H	223	Mus musculus	Mutation(s): 0
Protein Feature View Expand
Reference Sequence