1NHL

SNAP-23N Structure

Summary for 1NHL

• Entry DOI: 10.2210/pdb1nhl/pdb
• Related: 1SFC
• Descriptor: Synaptosomal-associated protein 23 (2 entities in total)
• Functional Keywords: snare, coiled-coil, protein transport
• Biological source: Homo sapiens (human)
• Cellular location: Cell membrane; Peripheral membrane protein: O00161
• Total number of polymer chains: 1
• Total formula weight: 6318.81

Authors

Freedman, S.J.,Song, H.K.,Xu, Y.,Eck, M.J. (deposition date: 2002-12-19, release date: 2003-04-15, Last modification date: 2024-11-20)

Primary citation

Freedman, S.J.,Song, H.K.,Xu, Y.,Sun, Z.Y.,Eck, M.J.
Homotetrameric Structure of the SNAP-23 N-terminal Coiled-coil Domain
J.Biol.Chem., 278:13462-13467, 2003

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.

PubMed: 12556468
DOI: 10.1074/jbc.M210483200

Experimental method

X-RAY DIFFRACTION (2.3 Å)