1nhl
From Proteopedia
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SNAP-23N Structure
Overview
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.
About this Structure
1NHL is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Homotetrameric structure of the SNAP-23 N-terminal coiled-coil domain., Freedman SJ, Song HK, Xu Y, Sun ZY, Eck MJ, J Biol Chem. 2003 Apr 11;278(15):13462-7. Epub 2003 Jan 29. PMID:12556468
Page seeded by OCA on Thu Feb 21 14:06:11 2008
Categories: Homo sapiens | Single protein | Eck, M J. | Freedman, S J. | Song, H K. | Xu, Y. | Coiled-coil | Snare
