7PQ5

Photorhabdus laumondii T6SS-associated Rhs protein carrying the Tre23 toxin domain

Summary for 7PQ5

• Entry DOI: 10.2210/pdb7pq5/pdb
• EMDB information: 13587
• Descriptor: Tre23 (1 entity in total)
• Functional Keywords: rhs, tviss, t6ss, toxin
• Biological source: Photorhabdus laumondii subsp. laumondii TTO1
• Total number of polymer chains: 1
• Total formula weight: 165588.83

Authors

Jurenas, D.,Talachia Rosa, L.,Rey, M.,Chamot-Rooke, J.,Fronzes, R.,Cascales, E. (deposition date: 2021-09-16, release date: 2021-12-01, Last modification date: 2024-07-17)

Primary citation

Jurenas, D.,Rosa, L.T.,Rey, M.,Chamot-Rooke, J.,Fronzes, R.,Cascales, E.
Mounting, structure and autocleavage of a type VI secretion-associated Rhs polymorphic toxin.
Nat Commun, 12:6998-6998, 2021

PubMed Abstract: Bacteria have evolved toxins to outcompete other bacteria or to hijack host cell pathways. One broad family of bacterial polymorphic toxins gathers multidomain proteins with a modular organization, comprising a C-terminal toxin domain fused to a N-terminal domain that adapts to the delivery apparatus. Polymorphic toxins include bacteriocins, contact-dependent growth inhibition systems, and specialized Hcp, VgrG, PAAR or Rhs Type VI secretion (T6SS) components. We recently described and characterized Tre23, a toxin domain fused to a T6SS-associated Rhs protein in Photorhabdus laumondii, Rhs1. Here, we show that Rhs1 forms a complex with the T6SS spike protein VgrG and the EagR chaperone. Using truncation derivatives and cross-linking mass spectrometry, we demonstrate that VgrG-EagR-Rhs1 complex formation requires the VgrG C-terminal β-helix and the Rhs1 N-terminal region. We then report the cryo-electron-microscopy structure of the Rhs1-EagR complex, demonstrating that the Rhs1 central region forms a β-barrel cage-like structure that encapsulates the C-terminal toxin domain, and provide evidence for processing of the Rhs1 protein through aspartyl autoproteolysis. We propose a model for Rhs1 loading on the T6SS, transport and delivery into the target cell.

PubMed: 34853317
DOI: 10.1038/s41467-021-27388-0

Experimental method

ELECTRON MICROSCOPY (3.17 Å)