Assembly of the type II secretion system such as found in Vibrio cholerae depends on the novel Pilotin AspS

Authors

Rhys A. Dunstan, Monash University, Australia
Eva Heinz, Monash University, Australia
Lakshmi C. Wijeyewickrema, Monash University, Australia
Robert N. Pike, Monash University, Australia
Anthony W. Purcell, Monash University, Australia
Timothy J. Evans, University of KentuckyFollow
Judyta Praszkier, University of Melbourne, Australia
Roy M. Robins-Browne, University of Melbourne, Australia
Richard A. Strugnell, University of Melbourne, Australia
Konstantin V. Korotkov, University of KentuckyFollow
Trevor Lithgow, Monash University, Australia

Abstract

The Type II Secretion System (T2SS) is a molecular machine that drives the secretion of fully-folded protein substrates across the bacterial outer membrane. A key element in the machinery is the secretin: an integral, multimeric outer membrane protein that forms the secretion pore. We show that three distinct forms of T2SSs can be distinguished based on the sequence characteristics of their secretin pores. Detailed comparative analysis of two of these, the Klebsiella-type and Vibrio-type, showed them to be further distinguished by the pilotin that mediates their transport and assembly into the outer membrane. We have determined the crystal structure of the novel pilotin AspS from Vibrio cholerae, demonstrating convergent evolution wherein AspS is functionally equivalent and yet structurally unrelated to the pilotins found in Klebsiella and other bacteria. AspS binds to a specific targeting sequence in the Vibrio-type secretins, enhances the kinetics of secretin assembly, and homologs of AspS are found in all species of Vibrio as well those few strains of Escherichia and Shigella that have acquired a Vibrio-type T2SS.

Document Type

Article

Publication Date

1-10-2013

Notes/Citation Information

Published in PLoS Pathogens, v. 9, no. 1, e1003117.

© 2013 Dunstan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Digital Object Identifier (DOI)

http://dx.doi.org/10.1371/journal.ppat.1003117

Repository Citation

Dunstan, Rhys A.; Heinz, Eva; Wijeyewickrema, Lakshmi C.; Pike, Robert N.; Purcell, Anthony W.; Evans, Timothy J.; Praszkier, Judyta; Robins-Browne, Roy M.; Strugnell, Richard A.; Korotkov, Konstantin V.; and Lithgow, Trevor, "Assembly of the type II secretion system such as found in Vibrio cholerae depends on the novel Pilotin AspS" (2013). Molecular and Cellular Biochemistry Faculty Publications. 19.
https://uknowledge.uky.edu/biochem_facpub/19