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Cys-Cys cross-linking shows contact between the N-terminus of lethal factor and Phe427 of the anthrax toxin pore.

ABSTRACT: Electrophysiological studies of wild-type and mutated forms of anthrax protective antigen (PA) suggest that the Phe clamp, a structure formed by the Phe427 residues within the lumen of the oligomeric PA pore, binds the unstructured N-terminus of the lethal factor and the edema factor during initiation of translocation. We now show by electrophysiological measurements and gel shift assays that a single Cys introduced into the Phe clamp can form a disulfide bond with a Cys placed at the N-terminus of the isolated N-terminal domain of LF. These results demonstrate direct contact of these Cys residues, supporting a model in which the interaction of the unstructured N-terminus of the translocated moieties with the Phe clamp initiates N- to C-terminal threading of these moieties through the pore.

SUBMITTER: Janowiak BE

PROVIDER: S-EPMC3082969 | biostudies-literature | 2011 May

REPOSITORIES: biostudies-literature

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Cys-Cys cross-linking shows contact between the N-terminus of lethal factor and Phe427 of the anthrax toxin pore.

Janowiak Blythe E BE Jennings-Antipov Laura D LD Collier R John RJ

Biochemistry 20110406 17

Electrophysiological studies of wild-type and mutated forms of anthrax protective antigen (PA) suggest that the Phe clamp, a structure formed by the Phe427 residues within the lumen of the oligomeric PA pore, binds the unstructured N-terminus of the lethal factor and the edema factor during initiation of translocation. We now show by electrophysiological measurements and gel shift assays that a single Cys introduced into the Phe clamp can form a disulfide bond with a Cys placed at the N-terminus ...[more]

PMID: 21425869

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