1v1g
STRUCTURE OF THE ARABIDOPSIS THALIANA SOS3 COMPLEXED WITH CALCIUM(II) ION
OverviewOverview
The Arabidopsis thaliana SOS3 gene encodes a calcium sensor that is required for plant salt tolerance. The SOS3 protein binds to and activates the self-inhibited SOS2 protein kinase, which mediates the expression and activities of various transporters important for ion homeostasis under salt stress. SOS3 belongs to a unique family of calcium-binding proteins that contain two pairs of EF hand motifs with four putative metal-binding sites. We report the crystal structure of a dimeric SOS3 protein in complex with calcium, and with calcium and manganese. Analytical ultracentrifugation experiments and circular dichroism measurements show that calcium binding is responsible for the dimerization of SOS3. This leads to a change in the global shape and surface properties of the protein that may be sufficient to transmit the Ca(2+) signal elicited during salt stress.
About this StructureAbout this Structure
1V1G is a Single protein structure of sequence from Arabidopsis thaliana. Full crystallographic information is available from OCA.
ReferenceReference
The structure of the Arabidopsis thaliana SOS3: molecular mechanism of sensing calcium for salt stress response., Sanchez-Barrena MJ, Martinez-Ripoll M, Zhu JK, Albert A, J Mol Biol. 2005 Feb 4;345(5):1253-64. Epub 2004 Dec 8. PMID:15644219 Page seeded by OCA on Sat May 3 11:58:07 2008