Demonstration of RNA N‐Glycosidase Activity of a Vero Toxin (VT2 Variant) Produced by Escherichia coli 091: H21 from a Patient with the Hemolytic Uremic Syndrome

A new Vero toxin purified from Escherichia coli O91:H21 isolated from a patient with the hemolytic uremic syndrome (VT2vh) was shown to inhibit elongation factor 1-dependent aminoacyl-tRNA binding to ribosomes, resulting in inhibition of protein synthesis in rabbit reticulocytes. VT2vh, like Shiga toxin, VT1 and VT2, showed RNA N-glycosidase activity and cleaved the N-glycosidic bond of the adenosine residue at position 4324 in 28S ribosomal RNA.