Calcium-induced folding and stabilization of the intrinsically disordered RTX domain of the CyaA toxin.

ABSTRACT: The adenylate cyclase toxin (CyaA) is one of the major virulence factors of Bordetella pertussis, the causative agent of whooping cough. Its C-terminal region, the receptor-binding domain (RD), contains ∼40 calcium-binding Repeat in ToXin (RTX) motifs, which are characteristic of many virulence factors of pathogenic bacteria. We previously showed that RD is intrinsically disordered in the absence of calcium and acquires its functional three-dimensional structure upon calcium binding. To gain further insight into the physicochemical properties of RD, we characterized its calcium-induced conformational and stability changes by combining spectroscopic approaches. We show that RD, in the absence of calcium, adopts premolten globule conformations, due in part to the strong internal electrostati

SUBMITTER: Chenal A 

PROVIDER: S-EPMC2998614 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature