Mechanism of actin-dependent activation of nucleotidyl cyclase toxins from bacterial human pathogens

Abstract

The nucleotidyl cyclase toxin exoenzyme Y (ExoY), which is secreted by the human pathogens Pseudomonas aeruginosa and Vibrio vulnificus is activated by actin. Here, the authors present the cryo-EM structures of PaExoY bound to F-actin and VvExoY in complex with G-actin-profilin. These structures together with molecular dynamics simulations and enzymatic assays provide insights into the activation mechanism for both bacterial cyclase toxin families that interact with either F- or G-actin.