Allosteric control of syntaxin 1a by Munc18-1: characterization of the open and closed conformations of syntaxin.

ABSTRACT: Syntaxin 1a is a plasma membrane soluble N-ethylmaleimide-sensitive factor attachment receptor protein (SNARE) that contains an H3 domain (SNARE motif) and a regulatory Habc domain. These regions associate to produce a closed state, which is generally thought to suppress assembly of syntaxin into the SNARE complex. However, the molecular nature of the closed and open states of syntaxin is not well defined. Here, we use electron paramagnetic resonance spectroscopy to characterize conformational exchange in syntaxin. The data indicate that the H3 segment is in equilibrium between ordered and disordered states that have significant populations. In solution, the central region of the H3 segment is positioned close to the Habc domain and the configuration of syntaxin 1a is dominated by a closed

SUBMITTER: Dawidowski D 

PROVIDER: S-EPMC3617443 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature