2NPS: Crystal Structure Of The Early Endosomal Snare Complex

SNARE proteins mediate membrane fusion in eukaryotic cells. They contain conserved SNARE motifs that are usually located adjacent to a C-terminal transmembrane domain. SNARE motifs spontaneously assemble into four helix bundles, with each helix belonging to a different subfamily. Liposomes containing SNAREs spontaneously fuse with each other, but it is debated how the SNAREs are distributed between the membranes. Here, we report that the SNAREs mediating homotypic fusion of early endosomes fuse liposomes in five out of seven possible combinations, in contrast to previously studied SNAREs involved in heterotypic fusion events. The crystal structure of the early endosomal SNARE complex resembles that of the neuronal and late endosomal complexes, but differs in surface side-chain interactions. We conclude that homotypic fusion reactions may proceed with multiple SNARE topologies, suggesting that the conserved SNARE structure allows for flexibility in the initial interactions needed for fusion.
PDB ID: 2NPSDownload
MMDB ID: 43494
PDB Deposition Date: 2006/10/30
Updated in MMDB: 2017/10
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Rattus norvegicus
Similar Structures:
Biological Unit for 2NPS: tetrameric; determined by author and by software (PISA)
Molecular Components in 2NPS
Label Count Molecule
Proteins (4 molecules)
Vesicle-associated Membrane Protein 4(Gene symbol: Vamp4)
Molecule annotation
Syntaxin 13
Molecule annotation
Vesicle Transport Through Interaction With T-snares Homolog 1A(Gene symbol: Vti1a)
Molecule annotation
Syntaxin-6(Gene symbol: STX6)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB