Acta Crystallographica Section F

Structural Biology and Crystallization Communications

Volume 61, Part 10 (October 2005)

crystallization communications

Acta Cryst. (2005). F61, 879-881 [ doi:10.1107/S1744309105026758 ]

Crystallization and preliminary X-ray diffraction analysis of calexcitin from Loligo pealei: a neuronal protein implicated in learning and memory

G. D. E. Beaven, P. T. Erskine, J. N. Wright, F. Mohammed, R. Gill, S. P. Wood, J. Vernon, K. P. Giese and J. B. Cooper

Abstract: The neuronal protein calexcitin from the long-finned squid Loligo pealei has been expressed in Escherichia coli and purified to homogeneity. Calexcitin is a 22 kDa calcium-binding protein that becomes up-regulated in invertebrates following Pavlovian conditioning and is likely to be involved in signal transduction events associated with learning and memory. Recombinant squid calexcitin has been crystallized using the hanging-drop vapour-diffusion technique in the orthorhombic space group P2₁2₁2₁. The unit-cell parameters of a = 46.6, b = 69.2, c = 134.8 Å suggest that the crystals contain two monomers per asymmetric unit and have a solvent content of 49%. This crystal form diffracts X-rays to at least 1.8 Å resolution and yields data of high quality using synchrotron radiation.

Keywords: calexcitin; calcium-binding proteins.