The members of this family are are sequences that are similar to the N-terminal half of the ShET2 enterotoxin produced by Shigella flexneri (Swiss:Q47635) and Escherichia coli (Swiss:Q47634). This protein was found to confer toxigenicity in the Ussing chamber, and the N-terminal region was found to be important for the protein's enterotoxic effect. It is thought to be a hydrophobic protein that forms inclusion bodies within the bacterial cell, and may be secreted by the Mxi system [1]. Most members of this family are annotated as putative enterotoxins, but one member (Swiss:Q8X606) is a regulator of acetyl CoA synthetase, and another two members (Swiss:P76205 and Swiss:P23325) are annotated as ankyrin-like regulatory proteins and contain Ank repeats (Pfam:PF00023).

1: Identification and cloning of a novel plasmid-encoded enterotoxin of enteroinvasive Escherichia coli and Shigella strains. Nataro JP, Seriwatana J, Fasano A, Maneval DR, Guers LD, Noriega F, Dubovsky F, Levine MM, Morris JG Jr; Infect Immun 1995;63:4721-4728. PMID:7591128