Cancer Institute A national cancer institute
designated cancer center

Matthew Bogyo

Publication Details

  • Defining an allosteric circuit in the cysteine protease domain of Clostridium difficile toxins NATURE STRUCTURAL & MOLECULAR BIOLOGY Shen, A., Lupardus, P. J., Gersch, M. M., Puri, A. W., Albrow, V. E., Garcia, K. C., Bogyo, M. 2011; 18 (3): 364-U158


    An internal cysteine protease domain (CPD) autoproteolytically regulates Clostridium difficile glucosylating toxins by releasing a cytotoxic effector domain into target cells. CPD activity is itself allosterically regulated by the eukaryote-specific molecule inositol hexakisphosphate (InsP(6)). Although allostery controls the function of most proteins, the molecular details underlying this regulatory mechanism are often difficult to characterize. Here we use chemical probes to show that apo-CPD is in dynamic equilibrium between active and inactive states. InsP(6) markedly shifts this equilibrium toward an active conformer that is further restrained upon binding a suicide substrate. Structural analyses combined with systematic mutational and disulfide bond engineering studies show that residues within a ?-hairpin region functionally couple the InsP(6)-binding site to the active site. Collectively, our results identify an allosteric circuit that allows bacterial virulence factors to sense and respond to the eukaryotic environment.

    View details for DOI 10.1038/nsmb.1990

    View details for Web of Science ID 000288072200019

    View details for PubMedID 21317893

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