1epu
From Proteopedia
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X-RAY CRYSTAL STRUCTURE OF NEURONAL SEC1 FROM SQUID
Overview
BACKGROUND: Sec1-like molecules have been implicated in a variety of, eukaryotic vesicle transport processes including neurotransmitter release, by exocytosis. They regulate vesicle transport by binding to a t-SNARE, from the syntaxin family. This process is thought to prevent SNARE complex, formation, a protein complex required for membrane fusion. Whereas Sec1, molecules are essential for neurotransmitter release and other secretory, events, their interaction with syntaxin molecules seems to represent a, negative regulatory step in secretion. RESULTS: Here we report the X-ray, crystal structure of a neuronal Sec1 homologue from squid, s-Sec1, at 2.4, A resolution. Neuronal s-Sec1 is a modular protein that folds into a, V-shaped three-domain assembly. Peptide and mutagenesis studies are, discussed with respect to the mechanism of Sec1 regulation. Comparison of, the structure of squid s-Sec1 with the previously determined structure of, rat neuronal Sec1 (n-Sec1) bound to syntaxin-1a indicates conformational, rearrangements in domain III induced by syntaxin binding. CONCLUSIONS: The, crystal structure of s-Sec1 provides the molecular scaffold for a number, of molecular interactions that have been reported to affect Sec1 function., The structural differences observed between s-Sec1 and the structure of a, rat n-Sec1-syntaxin-1a complex suggest that local conformational changes, are sufficient to release syntaxin-1a from neuronal Sec1, an active, process that is thought to involve additional effector molecule(s).
About this Structure
1EPU is a Single protein structure of sequence from Loligo plei. Full crystallographic information is available from OCA.
Reference
The X-ray crystal structure of neuronal Sec1 from squid sheds new light on the role of this protein in exocytosis., Bracher A, Perrakis A, Dresbach T, Betz H, Weissenhorn W, Structure. 2000 Jul 15;8(7):685-94. PMID:10903948
Page seeded by OCA on Sat Nov 24 22:40:25 2007
