Expression, purification, crystallization and preliminary X-ray analysis of the i-carrageenase from Alteromonas fortis

This is the first crystallization report of a glycoside hydrolase which belongs to family 82. A recombinant form of His-tagged iota-carrageenase from Alteromonas fortis was expressed, purified and crystallized. Crystals were obtained by the vapour-diffusion method using polyethylene glycol (M-W = 6000) as a precipitant. They belong to space group P2(1), with unit-cell parameters a = 56.75, b = 91.04, c = 125.01 Angstrom, beta = 93.41 degrees. The unit cell contains two molecules in the asymmetric unit related by a non-crystallographic twofold axis. Crystals diffracted to 2.0 Angstrom resolution on a synchrotron beamline.