6U9F

Structure of Francisella PdpA-VgrG Complex, Lidded


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.35 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


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Literature

Atomic Structure of the Francisella T6SS Central Spike Reveals a Unique alpha-Helical Lid and a Putative Cargo.

Yang, X.Clemens, D.L.Lee, B.Y.Cui, Y.Zhou, Z.H.Horwitz, M.A.

(2019) Structure 27: 1811-1819.e6

  • DOI: 10.1016/j.str.2019.10.007
  • Primary Citation of Related Structures:  
    6U9E, 6U9F, 6U9G

  • PubMed Abstract: 
  • Francisella bacteria rely on a phylogenetically distinct type VI secretion system (T6SS) to escape host phagosomes and cause the fatal disease tularemia, but the structural and molecular mechanisms involved are unknown. Here we report the atomic structure of the Francisella T6SS central spike complex, obtained by cryo-electron microscopy ...

    Francisella bacteria rely on a phylogenetically distinct type VI secretion system (T6SS) to escape host phagosomes and cause the fatal disease tularemia, but the structural and molecular mechanisms involved are unknown. Here we report the atomic structure of the Francisella T6SS central spike complex, obtained by cryo-electron microscopy. Our structural and functional studies demonstrate that, unlike the single-protein spike composition of other T6SS subtypes, Francisella T6SS's central spike is formed by two proteins, PdpA and VgrG, akin to T4-bacteriophage gp27 and gp5, respectively, and that PdpA has unique characteristics, including a putative cargo within its cavity and an N-terminal helical lid. Structure-guided mutagenesis demonstrates that the PdpA N-terminal lid and C-terminal spike are essential to Francisella T6SS function. PdpA is thus both an adaptor, connecting VgrG to the tube, and a likely carrier of secreted cargo. These findings are important to understanding Francisella pathogenicity and designing therapeutics to combat tularemia.


    Organizational Affiliation

    Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA; Department of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA. Electronic address: mhorwitz@mednet.ucla.edu.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
PdpAA,
B [auth C],
C [auth E]
820Francisella tularensis subsp. novicida U112Mutation(s): 0 
Gene Names: pdpAFTN_1309AW25_695
UniProt
Find proteins for A0Q7H0 (Francisella tularensis subsp. novicida (strain U112))
Explore A0Q7H0 
Go to UniProtKB:  A0Q7H0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0Q7H0
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
VgrGD [auth B],
E [auth D],
F
189Francisella tularensis subsp. novicida U112Mutation(s): 0 
Gene Names: FTN_1312AW25_692
UniProt
Find proteins for A0Q7H3 (Francisella tularensis subsp. novicida (strain U112))
Explore A0Q7H3 
Go to UniProtKB:  A0Q7H3
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0Q7H3
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.35 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/Office of the DirectorUnited StatesAI125497

Revision History  (Full details and data files)

  • Version 1.0: 2019-10-23
    Type: Initial release
  • Version 1.1: 2021-05-05
    Changes: Database references