6uji
From Proteopedia
Low resolution crystal structure (5.5 A) of the anthrax toxin protective antigen heptamer prepore D425A mutant
Structural highlights
FunctionPAG_BACAN One of the three proteins composing the anthrax toxin, the agent which infects many mammalian species and that may cause death. PA binds to a receptor (ATR) in sensitive eukaryotic cells, thereby facilitating the translocation of the enzymatic toxin components, edema factor and lethal factor, across the target cell membrane. PA associated with LF causes death when injected, PA associated with EF produces edema. PA induces immunity to infection with anthrax. Publication Abstract from PubMedThe tripartite protein complex produced by anthrax bacteria (Bacillus anthracis) is a member of the AB family of beta-barrel pore-forming toxins. The protective antigen (PA) component forms an oligomeric prepore that assembles on the host cell surface and serves as a scaffold for binding of lethal and edema factors. Following endocytosis, the acidic environment of the late endosome triggers a pH-induced conformational rearrangement to promote maturation of the PA prepore to a functional, membrane spanning pore that facilitates delivery of lethal and edema factors to the cytosol of the infected host. Here, we show that the dominant-negative D425A mutant of PA stalls anthrax pore maturation in an intermediate state at acidic pH. Our 2.7 A cryo-EM structure of the intermediate state reveals structural rearrangements that involve constriction of the oligomeric pore combined with an intramolecular dissociation of the pore-forming module. In addition to defining the early stages of anthrax pore maturation, the structure identifies asymmetric conformational changes in the oligomeric pore that are influenced by the precise configuration of adjacent protomers. Structure of the Anthrax Protective Antigen D425A Dominant Negative Mutant Reveals a Stalled Intermediate State of Pore Maturation.,Scott H, Huang W, Andra K, Mamillapalli S, Gonti S, Day A, Zhang K, Mehzabeen N, Battaile KP, Raju A, Lovell S, Bann JG, Taylor DJ J Mol Biol. 2022 Mar 15;434(9):167548. doi: 10.1016/j.jmb.2022.167548. PMID:35304125[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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