An amphipathic alpha-helix including glutamates 509 and 516 is crucial for membrane translocation of adenylate cyclase toxin and modulates formation and cation selectivity of its membrane channels.


The Bordetella pertussis adenylate cyclase toxin-hemolysin (ACT or CyaA) is a multifunctional protein. It forms small cation-selective channels in target cell and lipid bilayer membranes and it delivers into cell cytosol the amino-terminal adenylate cyclase (AC) domain, which catalyzes uncontrolled conversion of ATP to cAMP and causes cell intoxication… (More)