2be4

Publication Abstract from PubMed

Many essential physiological processes are regulated by the modulation of calcium concentration in the cell. The EF-hand proteins represent a superfamily of calcium-binding proteins involved in calcium signaling and homeostasis. Secretagogin is a hexa-EF-hand protein that is highly expressed in pancreatic islet of Langerhans and neuroendocrine cells and may play a role in the trafficking of secretory granules. We present the X-ray structure of Danio rerio secretagogin, which is 73% identical to human secretagogin, in calcium-free form at 2.1-A resolution. Secretagogin consists of the three globular domains each of which contains a pair of EF-hand motifs. The domains are arranged into a V-shaped molecule with a distinct groove formed at the interface of the domains. Comparison of the secretagogin structure with the solution structure of calcium-loaded calbindin D(28K) revealed a striking difference in the spatial arrangement of their domains, which involves approximately 180 degrees rotation of the first globular domain with respect to the module formed by the remaining domains.

X-ray structure of Danio rerio secretagogin: A hexa-EF-hand calcium sensor.,Bitto E, Bingman CA, Bittova L, Frederick RO, Fox BG, Phillips GN Jr Proteins. 2009 Aug 1;76(2):477-83. PMID:19241471^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.