Homologous Superfamily

Enterotoxin (IPR008992)

Short name: Enterotoxin

Overlapping entries


Cholera toxin produced by Vibrio cholerae and heat-labile enterotoxin, produced by enterotoxigenic Escherichia coli, are AB5 heterohexamers, consisting of one A polypeptide and five identical B polypeptides, with an ADP-ribosylating A subunit and a GM1 receptor binding B pentamer. These toxins are among the most potent mucosal adjuvants known. The B pentamer is required for binding to the cell surface receptor ganglioside GM1. The A subunit can be proteolytically cleaved within the single disulphide-linked loop between two cysteine residues to produce the enzymatically active A1 polypeptide and the smaller A2 polypeptide that links fragment A1 to the B pentamer. Upon entry into enterocytes by endocytosis and following reduction and translocation, CT-A1 ADP-ribosylates a regulatory G-protein (Gsalpha), which leads to constitutive activation of adenylate cyclase, increased intracellular concentration of cyclic AMP, and secretion of fluid and electrolytes into the lumen of the small intestine [PMID: 11395467].

All superfamily members contain a common OB-fold, a five-stranded beta-sheet coiled to form a closed beta-barrel capped by an alpha-helix located between the third and fourth strands.

GO terms

Biological Process

GO:0009405 pathogenesis

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.