3J9O

CryoEM structure of a type VI secretion system


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.7 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

wwPDB Validation 3D Report Full Report


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

  • 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, a ...

    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 Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Intracellular growth locus protein A
A, C, E, G, I, K
184Francisella tularensis subsp. novicida (strain U112)Mutation(s): 0 
Gene Names: iglA
Find proteins for A0Q7I5 (Francisella tularensis subsp. novicida (strain U112))
Go to UniProtKB:  A0Q7I5
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Intracellular growth locus protein B
B, D, F, H, J, L
506Francisella tularensis subsp. novicida (strain U112)Mutation(s): 0 
Gene Names: iglB
Find proteins for A0Q7I4 (Francisella tularensis subsp. novicida (strain U112))
Go to UniProtKB:  A0Q7I4
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.7 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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