SNAP-23N Structure

Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.316 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.277 

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This is version 1.2 of the entry. See complete history


Homotetrameric Structure of the SNAP-23 N-terminal Coiled-coil Domain

Freedman, S.J.Song, H.K.Xu, Y.Sun, Z.Y.Eck, M.J.

(2003) J Biol Chem 278: 13462-13467

  • DOI: https://doi.org/10.1074/jbc.M210483200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    SNARE proteins mediate intracellular membrane fusion by forming a coiled-coil complex to merge opposing membranes. A "fusion-active" neuronal SNARE complex is a parallel four-helix bundle containing two coiled-coil domains from SNAP-25 and one coiled-coil domain each from syntaxin-1a and VAMP-2. "Prefusion" assembly intermediate complexes can also form from these SNAREs. We studied the N-terminal coiled-coil domain of SNAP-23 (SNAP-23N), a non-neuronal homologue of SNAP-25, and its interaction with other coiled-coil domains. SNAP-23N can assemble spontaneously with the coiled-coil domains from SNAP-23C, syntaxin-4, and VAMP-3 to form a heterotetrameric complex. Unexpectedly, pure SNAP-23N crystallizes as a coiled-coil homotetrameric complex. The four helices have a parallel orientation and are symmetrical about the long axis. The complex is stabilized through the interaction of conserved hydrophobic residues comprising the a and d positions of the coiled-coil heptad repeats. In addition, a central, highly conserved glutamine residue (Gln-48) is buried within the interface by hydrogen bonding between glutamine side chains derived from adjacent subunits and to solvent molecules. A comparison of the SNAP-23N structure to other SNARE complex structures reveals how a simple coiled-coil motif can form diverse SNARE complexes.

  • Organizational Affiliation

    Division of Hemostasis and Thrombosis, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02115, USA. sfreedm2@caregroup.harvard.edu

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Synaptosomal-associated protein 2354Homo sapiensMutation(s): 2 
Gene Names: SNAP23
UniProt & NIH Common Fund Data Resources
Find proteins for O00161 (Homo sapiens)
Explore O00161 
Go to UniProtKB:  O00161
PHAROS:  O00161
GTEx:  ENSG00000092531 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO00161
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
Experimental Data & Validation

Experimental Data

  • Resolution: 2.30 Å
  • R-Value Free: 0.316 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.277 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 34.905α = 90
b = 34.905β = 90
c = 81.691γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
SCALEPACKdata scaling
HKL-2000data reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-04-15
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance