Expression, crystallization and preliminary X-ray analysis of the two amino-terminal Ig domains of the neural cell adhesion molecule (NCAM)

The two amino-terminal Ig domains of the rat neural cell adhesion molecule, NCAM, have been expressed in the yeast strain Pichia pastoris. The double domain consisting of 191 amino acids was overexpressed, purified and crysta llized. The crystals belong to the monoclinic space group P2(1), with unit- cell parameters a = 47.1, b = 122.5, c = 72.9 Angstrom and beta = 98.3 degr ees. Assuming there are four double domains per asymmetric unit, V-m is est imated to be 2.41 Angstrom(3) Da(-1) and the solvent content to be 42.3%, A native data set has been collected from a single flash-frozen crystal to 1 .85 Angstrom resolution.