Expression, purification, crystallization and preliminary X-ray analysis of the ι-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 ι-­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 P2₁, with unit-cell parameters a = 56.75, b = 91.04, c = 125.01 Å, β = 93.41°. The unit cell contains two molecules in the asymmetric unit related by a non-crystallographic twofold axis. Crystals diffracted to 2.0 Å resolution on a synchrotron beamline.