Download MendeleyCrystal structure and biophysical properties of a complex between the N-terminal SNARE region of SNAP25 and syntaxin 1a.
Misura, K.M., Gonzalez Jr., L.C., May, A.P., Scheller, R.H., Weis, W.I.(2001) J Biol Chem 276: 41301-41309
- PubMed: 11533035
- DOI: https://doi.org/10.1074/jbc.M106853200
- Primary Citation of Related Structures:
1JTH - PubMed Abstract:
SNARE proteins are required for intracellular membrane fusion. In the neuron, the plasma membrane SNAREs syntaxin 1a and SNAP25 bind to VAMP2 found on neurotransmitter-containing vesicles. These three proteins contain "SNARE regions" that mediate their association into stable tetrameric coiled-coil structures. Syntaxin 1a contributes one such region, designated H3, and SNAP25 contributes two SNARE regions to the fusogenic complex with VAMP2. Syntaxin 1a H3 (syn1aH3) and SNAP25 can form a stable assembly, which can then be bound by VAMP2 to form the full SNARE complex. Here we show that syn1aH3 can also form a stable but kinetically trapped complex with the N-terminal SNARE region of SNAP25 (S25N). The crystal structure of this complex reveals an extended parallel four-helix bundle similar to that of the core SNARE and the syn1aH3-SNAP25 complexes. The inherent ability of syn1aH3 and S25N to associate stably in vitro implies that the intracellular fusion machinery must prevent formation of, or remove, any non-productive complexes. Comparison with the syn1aH3-SNAP25 complex suggests that the linkage of the N- and C-terminal SNAP25 SNARE regions is kinetically advantageous in preventing formation of the non-productive syn1aH3-S25N complex. We also demonstrate that the syn1aH3-S25N complex can be disassembled by alpha-SNAP and N-ethylmaleimide-sensitive factor.
Organizational Affiliation:
Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA.
