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In situ structure and organisation of the type IX secretion system

Gorasia, Dhana G. and Chreifi, Georges and Seers, Christine A. and Butler, Catherine A. and Heath, Jacqueline E. and Glew, Michelle D. and McBride, Mark J. and Subramanian, Poorna and Kjaer, Andreas and Jensen, Grant J. and Veith, Paul D. and Reynolds, Eric C. (2020) In situ structure and organisation of the type IX secretion system. . (Unpublished)

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The Bacteroidetes type IX secretion system (T9SS) consists of at least 19 components that translocate proteins with a type A or type B C-terminal domain (CTD) signal across the outer membrane. The overall organisation and architecture of this system including how the secretion pore (Sov) interacts with the other components is unknown. We used cryo-electron tomography to obtain the first images of the T9SS including PorK/N rings inside intact Porphyromonas gingivalis cells. Using proteomics, we identified a novel complex between Sov, PorV and PorA and showed that Sov interacts with the PorK/N rings via PorW and a new component PGN_1783. A separate complex comprising the outer membrane β-barrel protein PorP, PorE, and the type B CTD protein PG1035 was also identified. Similarly, the Flavobacterium johnsoniae PorP-like protein, SprF was found bound to the major gliding motility adhesin, SprB. Based on these data, we propose cell surface anchorage for type B CTD proteins to PorP-like proteins and a unique model where the PorK/N rings function as an outer membrane barrier to maintain the close proximity of the translocon to the shuttle and attachment complexes inside the rings, ensuring the harmonized secretion and cell surface attachment of the T9SS substrates.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Kjaer, Andreas0000-0002-0096-5764
Jensen, Grant J.0000-0003-1556-4864
Reynolds, Eric C.0000-0002-6618-4856
Additional Information:The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. This version posted May 14, 2020. We acknowledge the use of the Mass Spectrometry and Proteomics Facility at the Bio21 Institute, The University of Melbourne, Australia. This work was supported by the Australian National Health and Medical Research Council grant ID 1123866, the Australian Government Department of Industry, Innovation and Science Grant ID 20080108 and the Australian Dental Research Foundation (ADRF) Grant ID 349-2018. This work was also supported by NIH GRANT A127401 to GJJ and NSF GRANT MCB-1516990 to MJM. Cryo-EM work was done at the Beckman Institute Resource Center for Transmission Electron Microscopy at Caltech.
Funding AgencyGrant Number
Australian National Health and Medical Research Council (NHMRC)1123866
Australian Government Department of Industry, Innovation and Science (Australia)20080108
Australian Dental Research Foundation349-2018
Record Number:CaltechAUTHORS:20200515-143951095
Persistent URL:
Official Citation:In situ structure and organisation of the type IX secretion system. Dhana G Gorasia, Georges Chreifi, Christine A Seers, Catherine A Butler, Jacqueline E Heath, Michelle D Glew, Mark J McBride, Poorna Subramanian, Andreas Kjaer, Grant J Jensen, Paul D Veith, Eric C Reynolds. bioRxiv 2020.05.13.094771; doi:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:103247
Deposited By: Tony Diaz
Deposited On:15 May 2020 21:49
Last Modified:16 Nov 2021 18:19

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