1k5w
THREE-DIMENSIONAL STRUCTURE OF THE SYNAPTOTAGMIN 1 C2B-DOMAIN: SYNAPTOTAGMIN 1 AS A PHOSPHOLIPID BINDING MACHINE
OverviewOverview
Synaptotagmin 1 probably functions as a Ca2+ sensor in neurotransmitter release via its two C2-domains, but no common Ca2+-dependent activity that could underlie a cooperative action between them has been described. The NMR structure of the C2B-domain now reveals a beta sandwich that exhibits striking similarities and differences with the C2A-domain. Whereas the bottom face of the C2B-domain has two additional alpha helices that may be involved in specialized Ca2+-independent functions, the top face binds two Ca2+ ions and is remarkably similar to the C2A-domain. Consistent with these results, but in contrast to previous studies, we find that the C2B-domain binds phospholipids in a Ca2+-dependent manner similarly to the C2A-domain. These results suggest a novel view of synaptotagmin function whereby the two C2-domains cooperate in a common activity, Ca2+-dependent phospholipid binding, to trigger neurotransmitter release.
About this StructureAbout this Structure
1K5W is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
ReferenceReference
Three-dimensional structure of the synaptotagmin 1 C2B-domain: synaptotagmin 1 as a phospholipid binding machine., Fernandez I, Arac D, Ubach J, Gerber SH, Shin O, Gao Y, Anderson RG, Sudhof TC, Rizo J, Neuron. 2001 Dec 20;32(6):1057-69. PMID:11754837 Page seeded by OCA on Fri May 2 22:21:01 2008