Probing the pH-dependent prepore to pore transition of Bacillus anthracis protective antigen with differential oxidative protein footprinting.

ABSTRACT: The protective antigen (PA) component of the anthrax toxin (ATx) plays an essential role in the pathogenesis of the bioterrorism bacterium Bacillus anthracis. After oligomerization on the cell surface and docking of lethal factor and/or edema factor, PA is internalized and undergoes a conformational change when exposed to the low pH of the endosome to form a membrane-penetrating pore. While the structure of the PA prepore has been determined, precise structural information regarding the pore state remains lacking. Oxidative protein footprinting (OPF) can provide dynamic structural information about a protein complex through analysis of amino acid oxidation both before and after a conformational change. In this study, PA at pH 7.5 and 5.5 was exposed to hydroxyl radicals generated by ionizi

SUBMITTER: Smedley JG 

PROVIDER: S-EPMC2645544 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature