3kwv
From Proteopedia
Structural basis for the unfolding of anthrax lethal factor by protective antigen oligomers
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 protein transporter anthrax lethal toxin is composed of protective antigen (PA), a transmembrane translocase, and lethal factor (LF), a cytotoxic enzyme. After its assembly into holotoxin complexes, PA forms an oligomeric channel that unfolds LF and translocates it into the host cell. We report the crystal structure of the core of a lethal toxin complex to 3.1-A resolution; the structure contains a PA octamer bound to four LF PA-binding domains (LF(N)). The first alpha-helix and beta-strand of each LF(N) unfold and dock into a deep amphipathic cleft on the surface of the PA octamer, which we call the alpha clamp. The alpha clamp possesses nonspecific polypeptide binding activity and is functionally relevant to efficient holotoxin assembly, PA octamer formation, and LF unfolding and translocation. This structure provides insight into the mechanism of translocation-coupled protein unfolding. Structural basis for the unfolding of anthrax lethal factor by protective antigen oligomers.,Feld GK, Thoren KL, Kintzer AF, Sterling HJ, Tang II, Greenberg SG, Williams ER, Krantz BA Nat Struct Mol Biol. 2010 Oct 31. PMID:21037566[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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