Shiga toxin 1 (Stx1)

Shiga toxin 1 is a bacterial protein toxin produced by *Shigella dysenteriae* type 1 and Shiga toxin-producing *Escherichia coli* (STEC). It is an AB5-type holotoxin composed of one enzymatically active A subunit and a pentamer of B subunits. The B subunits bind to the cellular glycolipid globotriaosylceramide (Gb3) on host endothelial cells, facilitating endocytosis and retrograde trafficking to the endoplasmic reticulum. The A subunit then enters the cytosol and enzymatically removes a specific adenine from 28S rRNA, inactivating the ribosome and inhibiting protein synthesis, leading to cell death. Shiga toxin 1 is a major virulence factor in severe gastrointestinal infections, including hemorrhagic colitis and hemolytic uremic syndrome, particularly in children[1][2][3][6]. Key distinctions: Shiga toxin 1 is antigenically distinct from Shiga toxin 2 (Stx2). While both have similar mechanisms, Stx2 is generally more toxic in animal models and human disease. The primary clinical relevance of Shiga toxin 1 is as a virulence factor in infectious disease, making it a potential—but highly challenging—target for therapeutic intervention[1][3].

Other names

Shiga-like toxin 1Stx1aVerotoxin 1Vero toxin 1Shiga-toxin type 1

Ribosome inactivation by removing a specific adenine residue from the 28S rRNA of the 60S subunit, halting protein synthesis[1][3]. Cellular entry via binding B pentamer to the glycosphingolipid receptor globotriaosylceramide (Gb3)[1][2][3].