Protein Interactome Analysis of the Type IX Secretion System Identifies PorW as the Missing Link between the PorK/N Ring Complex and the Sov Translocon

Dhana Gorasia (1) , Ignacio Lunar Silva (2) , Catherine Butler (1) , Maïalène Chabalier (2) , Thierry Doan (2) , E. Cascales (2) , Paul Veith (1) , Eric C Reynolds (1)

1 Melbourne Dental School, University of Melbourne, Melbourne, Australia
2 LISM - Laboratoire d'ingénierie des systèmes macromoléculaires

The type IX secretion system (T9SS) transports cargo proteins through the outer membrane of Bacteroidetes and attaches them to the cell surface for func- tions including pathogenesis, gliding motility, and degradation of carbon sources. The T9SS comprises at least 20 different proteins and includes several modules: the trans- envelope core module comprising the PorL/M motor and the PorK/N ring, the outer membrane Sov translocon, and the cell attachment complex. However, the spatial or- ganization of these modules is unknown. We have characterized the protein interac- tome of the Sov translocon in Porphyromonas gingivalis and identified Sov-PorV-PorA as well as Sov-PorW-PorN-PorK to be novel networks. PorW also interacted with PGN_1783 (PorD), which was required for maximum secretion efficiency. The identifi- cation of PorW as the missing link completes a continuous interaction network from the PorL/M motor to the Sov translocon, providing a pathway for cargo delivery and energy transduction from the inner membrane to the secretion pore.

Domaines: Biochimie, Biologie Moléculaire; Microbiologie et Parasitologie

Dhana Gorasia, Ignacio Lunar Silva, Catherine Butler, Maïalène Chabalier, Thierry Doan, et al.. Protein Interactome Analysis of the Type IX Secretion System Identifies PorW as the Missing Link between the PorK/N Ring Complex and the Sov Translocon. Microbiology Spectrum, 2022, 10 (1). ⟨hal-03795759⟩