Inhibition of Protein Synthesis by Exotoxins from Corynebacterium diphtheriae and Pseudomonas aeruginosa

Abstract

Among the organisms known to produce toxins which inhibit protein synthesis specifically are two pathogenic bacteria, Corynebacterium diphtheriae and Pseudomonas aeruginosa. Although the two pathogens differ markedly in gross characteristics, habitat, transmissibility, and infectious characterisitics, it now seems clear that the major toxic proteins produced by the two have almost identical modes of action at the molecular level. Both catalyze an unusual covalent modification of elongation factor 2 (EF-2), an essential factor in protein synthesis. The factor is thereby inactivated, and protein synthesis is inhibited. This inhibition is believed to be largely or partly responsible for the major toxemic symptoms observed in infections by the two pathogens.