Structure of the bacterial type VI secretion system effector RhsA.

Experimental Data Snapshot

  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

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Structure of a bacterial Rhs effector exported by the type VI secretion system.

Gunther, P.Quentin, D.Ahmad, S.Sachar, K.Gatsogiannis, C.Whitney, J.C.Raunser, S.

(2022) PLoS Pathog 18: e1010182-e1010182

  • DOI: https://doi.org/10.1371/journal.ppat.1010182
  • Primary Citation of Related Structures:  
    7Q5P, 7Q97

  • PubMed Abstract: 

    The type VI secretion system (T6SS) is a widespread protein export apparatus found in Gram-negative bacteria. The majority of T6SSs deliver toxic effector proteins into competitor bacteria. Yet, the structure, function, and activation of many of these effectors remains poorly understood. Here, we present the structures of the T6SS effector RhsA from Pseudomonas protegens and its cognate T6SS spike protein, VgrG1, at 3.3 Å resolution. The structures reveal that the rearrangement hotspot (Rhs) repeats of RhsA assemble into a closed anticlockwise β-barrel spiral similar to that found in bacterial insecticidal Tc toxins and in metazoan teneurin proteins. We find that the C-terminal toxin domain of RhsA is autoproteolytically cleaved but remains inside the Rhs 'cocoon' where, with the exception of three ordered structural elements, most of the toxin is disordered. The N-terminal 'plug' domain is unique to T6SS Rhs proteins and resembles a champagne cork that seals the Rhs cocoon at one end while also mediating interactions with VgrG1. Interestingly, this domain is also autoproteolytically cleaved inside the cocoon but remains associated with it. We propose that mechanical force is required to remove the cleaved part of the plug, resulting in the release of the toxin domain as it is delivered into a susceptible bacterial cell by the T6SS.

  • Organizational Affiliation

    Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Rhs family protein
A, B
1,426Pseudomonas protegens Pf-5Mutation(s): 0 
Gene Names: PFL_6096
Find proteins for Q4K3M9 (Pseudomonas fluorescens (strain ATCC BAA-477 / NRRL B-23932 / Pf-5))
Explore Q4K3M9 
Go to UniProtKB:  Q4K3M9
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ4K3M9
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Max Planck Society--
Natural Sciences and Engineering Research Council (NSERC, Canada)RGPIN 2017 05350
Other private--

Revision History  (Full details and data files)

  • Version 1.0: 2021-12-22
    Type: Initial release
  • Version 1.1: 2022-02-02
    Changes: Database references