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Updated: Aug 4, 2026

Monitoring the Assembly of a Secreted Bacterial Virulence Factor Using Site-specific Crosslinking
Published on: December 17, 2013
Crystal structure of the hexameric traffic ATPase of the Helicobacter pylori type IV secretion system
H J Yeo1, S N Savvides, A B Herr
1Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110, USA.
Abstract:
The type IV secretion system of Helicobacter pylori consists of 10--15 proteins responsible for transport of the transforming protein CagA into target epithelial cells. Secretion of CagA crucially depends on the hexameric ATPase, HP0525, a member of the VirB11-PulE family. We present the crystal structure of a binary complex of HP0525 bound to ADP. Each monomer consists of two domains formed by the N- and C-terminal halves of the sequence. ADP is bound at the interface between the two domains. In the hexamer, the N- and C-terminal domains form two rings, which together form a chamber open on one side and closed on the other. A model is proposed in which HP0525 functions as an inner membrane pore, the closure and opening of which is regulated by ATP binding and ADP release.
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