Contributors: Laboratoire d'ingénierie des systèmes macromoléculaires (LISM); Aix Marseille Université (AMU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS); Institut Européen de Chimie et Biologie (IECB); Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS); Microbiologie Fondamentale et Pathogénicité (MFP); Université Bordeaux Segalen - Bordeaux 2-Centre National de la Recherche Scientifique (CNRS); Spectrométrie de Masse pour la Biologie – Mass Spectrometry for Biology (UTechS MSBio); Institut Pasteur [Paris] (IP)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité); This work was funded by the Center National de la Recherche Scientifique, the Aix-Marseille Université, the Bordeaux Univ., the Institut Pasteur and by grants from the Agence Nationale de la Recherche (ANR-17-CE11-0039, ANR-20-CE11-0017), the Fondation pour la Recherche Médicale (FRM, DEQ20180339165), and the Fondation Bettencourt Schueller to EC. DJ was supported by a FRM post-doctoral fellowship (SPF201809007142). This work has benefitted from the facilities and expertize of the Biophysical and Structural Chemistry Platform (BPCS) at IECB.; ANR-17-CE11-0039,T6-PLATFORM,Une approche multidisciplinaire et intégrative pour comprendre l'assemblage, la structure et la dynamique d'une plateforme de queue contractile(2017); ANR-20-CE11-0017,FullContact,Une approche multidisciplinaire pour comprendre la structure et la dynamique du système de sécrétion de type VI(2020); Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Aix Marseille Université (AMU); Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut National de la Santé et de la Recherche Médicale (INSERM); Institut Pasteur [Paris]
نبذة مختصرة : 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.
Rights: CC BY
URL: http://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ (http://creativecommons.org/licenses/by/4.0/) .
Processing Request
No Comments.