Published In

Nature Structural and Molecular Biology

Document Type

Post-Print

Publication Date

10-2010

Subjects

Secretin, Cryomicroscopy, Bacterial proteins, Cholera toxin

Abstract

The type II secretion system (T2SS) is a macromolecular complex spanning the inner and outer membranes of Gram-negative bacteria. Remarkably, the T2SS secretes folded proteins including multimeric assemblies like cholera toxin and heat-labile enterotoxin from Vibrio cholerae and enterotoxigenic Escherichia coli, respectively. The major outer membrane T2SS protein is the “secretin” GspD. Electron cryomicroscopy reconstruction of the V. cholerae secretin at 19 Å resolution reveals a dodecameric structure reminiscent of a barrel with a large channel at its center that appears to contain a closed periplasmic gate. The GspD periplasmic domain forms a vestibule with a conserved constriction, and binds to a pentameric exoprotein and to the trimeric tip of the T2SS pseudopilus. By combining our results with structures of the cholera toxin and T2SS pseudopilus, we provide a structural basis for a possible secretion mechanism of the T2SS.

Description

This is the authors' manuscript of an article subsequently published in Nature Structural and Molecular Biology, 2010 October; 17 (10): 1226-1232. May be found at https://doi.org/10.1038/nsmb.1910.

Note: At the time of writing, Steve Reichow was affiliated with the University of Washington.

DOI

10.1038/nsmb.1910

Persistent Identifier

http://archives.pdx.edu/ds/psu/21525

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