1g8i
From Proteopedia
CRYSTAL STRUCTURE OF HUMAN FREQUENIN (NEURONAL CALCIUM SENSOR 1)
Overview
Frequenin, a member of a large family of myristoyl-switch calcium-binding proteins, functions as a calcium-ion sensor to modulate synaptic activity and secretion. We show that human frequenin colocalizes with ARF1 GTPase in COS-7 cells and occurs in similar cellular compartments as the phosphatidylinositol-4-OH kinase PI4Kbeta, the mammalian homolog of the yeast kinase PIK1. In addition, the crystal structure of unmyristoylated, calcium-bound human frequenin has been determined and refined to 1.9 A resolution. The overall fold of frequenin resembles those of neurocalcin and the photoreceptor, recoverin, of the same family, with two pairs of calcium-binding EF hands and three bound calcium ions. Despite the similarities, however, frequenin displays significant structural differences. A large conformational shift of the C-terminal region creates a wide hydrophobic crevice at the surface of frequenin. This crevice, which is unique to frequenin and distinct from the myristoyl-binding box of recoverin, may accommodate a yet unknown protein ligand.
About this Structure
1G8I is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Immunocytochemical localization and crystal structure of human frequenin (neuronal calcium sensor 1)., Bourne Y, Dannenberg J, Pollmann V, Marchot P, Pongs O, J Biol Chem. 2001 Apr 13;276(15):11949-55. Epub 2000 Nov 22. PMID:11092894 Page seeded by OCA on Fri May 2 17:16:38 2008
