PMID: 15326297 , Related PDB ids: 1TZN, 1TZO

Authors:

Lacy DB, Wigelsworth DJ, Melnyk RA, Harrison SC, Collier RJ

Title:

Structure of heptameric protective antigen bound to an anthrax toxin receptor: a role for receptor in pH-dependent pore formation.

Journal:

Proc Natl Acad Sci U S A. 2004 Sep 7;101(36):13147-51. Epub 2004 Aug 23.

Abstract:

After binding to cellular receptors and proteolytic activation, the protective antigen component of anthrax toxin forms a heptameric prepore. The prepore later undergoes pH-dependent conversion to a pore, mediating translocation of the edema and lethal factors to the cytosol. We describe structures of the prepore (3.6 A) and a prepore:receptor complex (4.3 A) that reveal the location of pore-forming loops and an unexpected interaction of the receptor with the pore-forming domain. Lower pH is required for prepore-to-pore conversion in the presence of the receptor, indicating that this interaction regulates pH-dependent pore formation. We present an example of a receptor negatively regulating pH-dependent membrane insertion.