2XHE

Crystal structure of the Unc18-syntaxin 1 complex from Monosiga brevicollis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.191 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Primordial Neurosecretory Apparatus Identified in the Choanoflagellate Monosiga Brevicollis.

Burkhardt, P.Stegmann, C.M.Cooper, B.Kloepper, T.H.Imig, C.Varoqueaux, F.Wahl, M.C.Fasshauer, D.

(2011) Proc Natl Acad Sci U S A 108: 15264

  • DOI: 10.1073/pnas.1106189108
  • Primary Citation of Related Structures:  
    2XHE

  • PubMed Abstract: 
  • SNARE protein-driven secretion of neurotransmitters from synaptic vesicles is at the center of neuronal communication. In the absence of the cytosolic protein Munc18-1, synaptic secretion comes to a halt. Although it is believed that Munc18-1 orchestrates SNARE complexes, its mode of action is still a matter of debate ...

    SNARE protein-driven secretion of neurotransmitters from synaptic vesicles is at the center of neuronal communication. In the absence of the cytosolic protein Munc18-1, synaptic secretion comes to a halt. Although it is believed that Munc18-1 orchestrates SNARE complexes, its mode of action is still a matter of debate. In particular, it has been challenging to clarify the role of a tight Munc18/syntaxin 1 complex, because this interaction interferes strongly with syntaxin's ability to form a SNARE complex. In this complex, two regions of syntaxin, the N-peptide and the remainder in closed conformation, bind to Munc18 simultaneously. Until now, this binary complex has been reported for neuronal tissues only, leading to the hypothesis that it might be a specialization of the neuronal secretion apparatus. Here we aimed, by comparing the core secretion machinery of the unicellular choanoflagellate Monosiga brevicollis with that of animals, to reconstruct the ancestral function of the Munc18/syntaxin1 complex. We found that the Munc18/syntaxin 1 complex from M. brevicollis is structurally and functionally highly similar to the vertebrate complex, suggesting that it constitutes a fundamental step in the reaction pathway toward SNARE assembly. We thus propose that the primordial secretion machinery of the common ancestor of choanoflagellates and animals has been co-opted for synaptic roles during the rise of animals.


    Organizational Affiliation

    Research Group Structural Biochemistry, Department of Neurobiology, and Research Group X-Ray Crystallography, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
UNC18 A650Monosiga brevicollisMutation(s): 0 
Gene Names: 32602
Find proteins for A9V0L3 (Monosiga brevicollis)
Explore A9V0L3 
Go to UniProtKB:  A9V0L3
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
SYNTAXIN1 B279Monosiga brevicollisMutation(s): 0 
Gene Names: 17976
Find proteins for A9UTG5 (Monosiga brevicollis)
Explore A9UTG5 
Go to UniProtKB:  A9UTG5
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.191 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 146.2α = 90
b = 146.2β = 90
c = 214.861γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XDSdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-06-29
    Type: Initial release
  • Version 1.1: 2012-03-14
    Changes: Database references, Version format compliance