| - | The Shiga toxin family, a group of cytotoxins associated with diarrhoeal, diseases and the haemolytic uraemic syndrome, includes Shiga toxin from, Shigella dysenteriae type 1 and verotoxins produced by enteropathogenic, Escherichia coli. The family belongs to the A-B class of bacterial toxins, which includes the cholera toxin family, pertussis and diphtheria toxins., These toxins all have bipartite structures consisting of an enzymatic A, subunit associated with a B oligomer which binds to specific cell-surface, receptors, but their amino-acid sequences and pathogenic mechanisms, differ. We have determined the crystal structure of the B oligomer of, verotoxin-1 from E. coli. The structure unexpectedly resembles that of the, B oligomer of the cholera toxin-like heat-labile enterotoxin from E. coli, despite the absence of detectable sequence similarity between these two, proteins. This result implies a distant evolutionary relationship between, the Shiga toxin and cholera toxin families. We suggest that the cell, surface receptor-binding site lies in a cleft between adjacent subunits of, the B pentamer, providing a potential target for drugs and vaccines to, prevent toxin binding and effect.
| + | |
| - | Crystal structure of the cell-binding B oligomer of verotoxin-1 from E. coli., Stein PE, Boodhoo A, Tyrrell GJ, Brunton JL, Read RJ, Nature. 1992 Feb 20;355(6362):748-50. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=1741063 1741063]
| + | |
