Single-molecule fluorescence resonance energy transfer reveals a dynamic equilibrium between closed and open conformations of syntaxin 1
2003 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 100, no 26, 15516-15521 p.Article in journal (Refereed) Published
Protein conformational transitions form the molecular basis of many cellular processes, such as signal transduction and membrane traffic. However, in many cases, little is known about their structural dynamics. Here we have used dynamic single-molecule fluorescence to study at high time resolution, conformational transitions of syntaxin 1, a soluble N-ethylmaleimide-sensitive factor attachment protein receptors protein essential for exocytotic membrane fusion. Sets of syntaxin double mutants were randomly labeled with a mix of donor and acceptor dye and their fluorescence resonance energy transfer was measured. For each set, all fluorescence information was recorded simultaneously with high time resolution, providing detailed information on distances and dynamics that were used to create structural models. We found that free syntaxin switches between an inactive closed and an active open configuration with a relaxation time of 0.8 ms, explaining why regulatory proteins are needed to arrest the protein in one conformational state.
Place, publisher, year, edition, pages
2003. Vol. 100, no 26, 15516-15521 p.
membrane-fusion, diffusing molecules, snare, spectroscopy, complex, identification, munc18, golgi
IdentifiersURN: urn:nbn:se:kth:diva-23042DOI: 10.1073/pnas.2331232100ISI: 000187554600043OAI: oai:DiVA.org:kth-23042DiVA: diva2:341740
QC 201005252010-08-102010-08-10Bibliographically approved