5CCI image
Entry Detail
PDB ID:
5CCI
Title:
Structure of the Mg2+-bound synaptotagmin-1 SNARE complex (short unit cell form)
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2015-07-02
Release Date:
2015-08-12
Method Details:
Experimental Method:
Resolution:
4.10 Å
R-Value Free:
0.32
R-Value Work:
0.27
R-Value Observed:
0.27
Space Group:
P 21 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Vesicle-associated membrane protein 2
Chain IDs:A
Chain Length:63
Number of Molecules:1
Biological Source:Rattus norvegicus
Polymer Type:polypeptide(L)
Description:Syntaxin-1A
Chain IDs:B
Chain Length:67
Number of Molecules:1
Biological Source:Rattus norvegicus
Polymer Type:polypeptide(L)
Description:Synaptosomal-associated protein 25
Chain IDs:C
Chain Length:77
Number of Molecules:1
Biological Source:Rattus norvegicus
Polymer Type:polypeptide(L)
Description:Synaptosomal-associated protein 25
Chain IDs:D
Chain Length:65
Number of Molecules:1
Biological Source:Rattus norvegicus
Polymer Type:polypeptide(L)
Description:Synaptotagmin-1
Chain IDs:E, F
Chain Length:281
Number of Molecules:2
Biological Source:Rattus norvegicus
Ligand Molecules
Primary Citation

Abstact

Synaptotagmin-1 and neuronal SNARE proteins have central roles in evoked synchronous neurotransmitter release; however, it is unknown how they cooperate to trigger synaptic vesicle fusion. Here we report atomic-resolution crystal structures of Ca(2+)- and Mg(2+)-bound complexes between synaptotagmin-1 and the neuronal SNARE complex, one of which was determined with diffraction data from an X-ray free-electron laser, leading to an atomic-resolution structure with accurate rotamer assignments for many side chains. The structures reveal several interfaces, including a large, specific, Ca(2+)-independent and conserved interface. Tests of this interface by mutagenesis suggest that it is essential for Ca(2+)-triggered neurotransmitter release in mouse hippocampal neuronal synapses and for Ca(2+)-triggered vesicle fusion in a reconstituted system. We propose that this interface forms before Ca(2+) triggering, moves en bloc as Ca(2+) influx promotes the interactions between synaptotagmin-1 and the plasma membrane, and consequently remodels the membrane to promote fusion, possibly in conjunction with other interfaces.

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Primary Citation of related structures