Members of this family, which are found in prokaryotic exotoxin A, catalyse the transfer of ADP ribose from nicotinamide adenine dinucleotide (NAD) to elongation factor-2 in eukaryotic cells, with subsequent inhibition of protein synthesis [1].

1: Crystal structure of the catalytic domain of Pseudomonas exotoxin A complexed with a nicotinamide adenine dinucleotide analog: implications for the activation process and for ADP ribosylation. Li M, Dyda F, Benhar I, Pastan I, Davies DR; Proc Natl Acad Sci U S A. 1996;93:6902-6906. PMID:8692916