Vam3p structure reveals conserved and divergent properties of syntaxins

Irina Dulubova, Tomohiro Yamaguchi, Yun Wang, Thomas C. Südhof, Jose Rizo-Rey

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119 Scopus citations

Abstract

Syntaxins and Sec1/munc18 proteins are central to intracellular membrane fusion. All syntaxins comprise a variable N-terminal region, a conserved SNARE motif that is critical for SNARE complex formation, and a transmembrane region. The N-terminal region of neuronal syntaxin 1A contains a three-helix domain that folds back onto the SNARE motif forming a 'closed' conformation; this conformation is required for munc18-1 binding. We have examined the generality of the structural properties of syntaxins by NMR analysis of Vam3p, a yeast syntaxin essential for vacuolar fusion. Surprisingly, Vam3p also has an N-terminal three-helical domain despite lacking apparent sequence homology with syntaxin 1A in this region. However, Vam3p does not form a closed conformation and its N-terminal domain is not required for binding to the Sec1/munc18 protein Vps33p, suggesting that critical distinctions exist in the mechanisms used by syntaxins to govern different types of membrane fusion.

Original languageEnglish (US)
Pages (from-to)258-264
Number of pages7
JournalNature Structural Biology
Volume8
Issue number3
DOIs
StatePublished - Mar 10 2001

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ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Genetics

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