6XM1

SM Protein Vps45 in Complex with Qa SNARE Tlg2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.197 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The Sec1/Munc18 protein Vps45 holds the Qa-SNARE Tlg2 in an open conformation.

Eisemann, T.J.Allen, F.Lau, K.Shimamura, G.R.Jeffrey, P.D.Hughson, F.M.

(2020) Elife 9

  • DOI: https://doi.org/10.7554/eLife.60724
  • Primary Citation of Related Structures:  
    6XJL, 6XM1, 6XMD

  • PubMed Abstract: 

    Fusion of intracellular trafficking vesicles is mediated by the assembly of SNARE proteins into membrane-bridging complexes. SNARE-mediated membrane fusion requires Sec1/Munc18-family (SM) proteins, SNARE chaperones that can function as templates to catalyze SNARE complex assembly. Paradoxically, the SM protein Munc18-1 traps the Qa-SNARE protein syntaxin-1 in an autoinhibited closed conformation. Here we present the structure of a second SM-Qa-SNARE complex, Vps45-Tlg2. Strikingly, Vps45 holds Tlg2 in an open conformation, with its SNARE motif disengaged from its Habc domain and its linker region unfolded. The domain 3a helical hairpin of Vps45 is unfurled, exposing the presumptive R-SNARE binding site to allow template complex formation. Although Tlg2 has a pronounced tendency to form homo-tetramers, Vps45 can rescue Tlg2 tetramers into stoichiometric Vps45-Tlg2 complexes. Our findings demonstrate that SM proteins can engage Qa-SNAREs using at least two different modes, one in which the SNARE is closed and one in which it is open.


  • Organizational Affiliation

    Department of Molecular Biology, Princeton University, Princeton, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Vps45
A, C
644Thermochaetoides thermophilaMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for G0S539 (Chaetomium thermophilum (strain DSM 1495 / CBS 144.50 / IMI 039719))
Explore G0S539 
Go to UniProtKB:  G0S539
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupG0S539
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Tlg2 Qa SNARE
B, D
284Thermochaetoides thermophilaMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for G0SGW7 (Chaetomium thermophilum (strain DSM 1495 / CBS 144.50 / IMI 039719))
Explore G0SGW7 
Go to UniProtKB:  G0SGW7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupG0SGW7
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.197 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 58.727α = 90
b = 180.057β = 90
c = 202.086γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
PHASERphasing
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR01GM071574

Revision History  (Full details and data files)

  • Version 1.0: 2020-08-19
    Type: Initial release
  • Version 1.1: 2020-09-02
    Changes: Database references
  • Version 1.2: 2023-10-18
    Changes: Data collection, Database references, Refinement description