Three-dimensional structure of the anthrax toxin pore inserted into lipid nanodiscs and lipid vesicles.

ABSTRACT: A major goal in understanding the pathogenesis of the anthrax bacillus is to determine how the protective antigen (PA) pore mediates translocation of the enzymatic components of anthrax toxin across membranes. To obtain structural insights into this mechanism, we constructed PA-pore membrane complexes and visualized them by using negative-stain electron microscopy. Two populations of PA pores were visualized in membranes, vesicle-inserted and nanodisc-inserted, allowing us to reconstruct two virtually identical PA-pore structures at 22-A resolution. Reconstruction of a domain 4-truncated PA pore inserted into nanodiscs showed that this domain does not significantly influence pore structure. Normal mode flexible fitting of the x-ray crystallographic coordinates of the PA prepore indicated t

SUBMITTER: Katayama H 

PROVIDER: S-EPMC2840458 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature