Purification, crystallization and preliminary diffraction study of β-galactosidase from Penicillium sp.

Crystals of an extracellular β-galactosidase from Penicillium sp. (MW = 120 ± 5 kDa) have been obtained from a sodium phosphate buffer using PEG as precipitant. The crystals belong to the tetragonal space group P4₁or P4₃, with unit-cell parameters a = b = 110.82, c = 161.28 Å, and diffract to 1.85 Å resolution at a synchrotron source.