Crystallization and preliminary X-ray crystallographic studies of recombinant bovine neurocalcin delta

Neurocalcins are novel brain-specific proteins that belong to a new subclass of the EF-hand super-family of calcium binding proteins, defined by the photoreceptor cell-specific protein recoverin (Terasawa et al., J. Biol. Chem. 267:19596-19599, 1992). Here we report the purification and crystallization of unmyristoylated recombinant bovine neurocalcin delta from Escherichia coli. Crystals of a bovine neurocalcin delta have been grown by macro-seeding at room temperature through vapor phase equilibration using the hanging drop technique with ammonium sulfate as the precipitating agent. The crystals diffract to at least 2.5 A resolution and belong to monoclinic space group P21 with unit cell dimensions a = 42.734 A, b = 94.343 A, c = 50.696 A, and beta = 98.37 degrees. The asymmetric unit contains two molecules, with corresponding crystal volume per protein mass (Vm) of 2.29 A3/Da and solvent fraction of 45% by volume, exhibiting an approximate 222 point symmetry.