3J9O

CryoEM structure of a type VI secretion system


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.70 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

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This is version 1.1 of the entry. See complete history


Literature

Atomic Structure of T6SS Reveals Interlaced Array Essential to Function.

Clemens, D.L.Ge, P.Lee, B.Y.Horwitz, M.A.Zhou, Z.H.

(2015) Cell 160: 940-951

  • DOI: 10.1016/j.cell.2015.02.005
  • Primary Citation of Related Structures:  
    3J9O

  • PubMed Abstract: 
  • Type VI secretion systems (T6SSs) are newly identified contractile nanomachines that translocate effector proteins across bacterial membranes. The Francisella pathogenicity island, required for bacterial phagosome escape, intracellular replication, and v ...

    Type VI secretion systems (T6SSs) are newly identified contractile nanomachines that translocate effector proteins across bacterial membranes. The Francisella pathogenicity island, required for bacterial phagosome escape, intracellular replication, and virulence, was presumed to encode a T6SS-like apparatus. Here, we experimentally confirm the identity of this T6SS and, by cryo electron microscopy (cryoEM), show the structure of its post-contraction sheath at 3.7 Å resolution. We demonstrate the assembly of this T6SS by IglA/IglB and secretion of its putative effector proteins in response to environmental stimuli. The sheath has a quaternary structure with handedness opposite that of contracted sheath of T4 phage tail and is organized in an interlaced two-dimensional array by means of β sheet augmentation. By structure-based mutagenesis, we show that this interlacing is essential to secretion, phagosomal escape, and intracellular replication. Our atomic model of the T6SS will facilitate design of drugs targeting this highly prevalent secretion apparatus.


    Organizational Affiliation

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; The California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA. Electronic address: hong.zhou@ucla.edu.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Intracellular growth locus protein A ACEGIK184Francisella tularensis subsp. novicida U112Mutation(s): 0 
Gene Names: iglAFTN_1324AW25_680
Find proteins for A0Q7I5 (Francisella tularensis subsp. novicida (strain U112))
Explore A0Q7I5 
Go to UniProtKB:  A0Q7I5
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Intracellular growth locus protein B BDFHJL506Francisella tularensis subsp. novicida U112Mutation(s): 0 
Gene Names: iglBFTN_1323AW25_681
Find proteins for A0Q7I4 (Francisella tularensis subsp. novicida (strain U112))
Explore A0Q7I4 
Go to UniProtKB:  A0Q7I4
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.70 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-03-18
    Type: Initial release
  • Version 1.1: 2018-07-18
    Changes: Author supporting evidence, Data collection