Solution and membrane-bound conformations of the tandem C2A and C2B domains of synaptotagmin 1: Evidence for bilayer bridging.

ABSTRACT: Synaptotagmin 1 (syt1) is a synaptic vesicle membrane protein that functions as the Ca(2)(+) sensor in neuronal exocytosis. Here, site-directed spin labeling was used to generate models for the solution and membrane-bound structures of a soluble fragment of syt1 containing its two C2 domains, C2A and C2B. In solution, distance restraints between the two C2 domains of syt1 were measured using double electron-electron resonance and used in a simulated annealing routine to generate models for the structure of the tandem C2A-C2B fragment. The data indicate that the two C2 domains are flexibly linked and do not interact with each other in solution, with or without Ca(2+). However, the favored orientation is one where the Ca(2+)-binding loops are oriented in opposite directions. A similar approa

SUBMITTER: Herrick DZ 

PROVIDER: S-EPMC2763419 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature