Enterotoxin type B

Staphylococcal/Streptococcal toxin, N-terminal domain
Crystal structure of the superantigen Spe-H (zinc bound) from Streptococcus pyogenes
Identifiers
Symbol	Staphylococcal/Streptococcal toxin, N-terminal domain
Pfam	PF01123
InterPro	IPR006173
PROSITE	PDOC00250
SCOP	1se3
SUPERFAMILY	1se3
Available protein structures: Pfam structures PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

In the field of molecular biology, enterotoxin type B, also known as Staphylococcal enterotoxin B (SEB), is an enterotoxin produced by the gram-positive bacteria Staphylococcus aureus. It is a common cause of food poisoning, with severe diarrhea, nausea and intestinal cramping often starting within a few hours of ingestion. Being quite stable, the toxin may remain active even after the contaminating bacteria are killed. It can withstand boiling at 100 °C for a few minutes.Gastroenteritis occurs because SEB is a superantigen, causing the immune system to release a large amount of cytokines that lead to significant inflammation.

Additionally, this protein is one of the causative agents of toxic shock syndrome.

The function of this protein is to facilitate the infection of the host organism. It is a virulence factor designed to induce pathogenesis. One of the major virulence exotoxins is the toxic shock syndrome toxin (TSST), which is secreted by the organism upon successful invasion. It causes a major inflammatory response in the host via superantigenic properties, and is the causative agent of toxic shock syndrome. It functions as a superantigen through activation of a significant fraction of T-cells (up to 20%) by cross-linking MHC class II molecules with T-cell receptors. TSST is a multisystem illness with several symptoms such as high fever, hypotension, dizziness, rash and peeling skin.