The Relationship between Structure and Binding Effect of Shiga Toxin

Abstract

Shiga toxin is an exotoxin protein. Shiga toxin is produced by the bacterium Shigella dysenteriae, or a similar one produced by E. coli, causing dysentery in humans. The motivation of this work is to explore the functions of the toxin through its structure. The Shiga toxin is a AB5 toxin that binds to specific receptors that are located on the cells’ surface to enter the cell. Transmission is from species such as swine, cattle, and deer that harbor toxigenic bacteria without syndromes but can be spread to humans through them shedding the toxin onto their feces. The Shiga toxin is an AB5 toxin, meaning the B subunit has the role of binding to cellular receptors, globotriaosylceramide (Gb3) or a glycoprotein which is located primarily on the surface of endothelial cells. Due to its structure, the Shiga toxin is unique for its highly selective receptors that allows the toxin to kill cells whether they are healthy or cancerous cells. With further research our team hopes to learn more about its functions and explore the possible benefits of the toxin.