Crystallization and preliminary diffraction analysis of a β-galactosidase from Trichoderma reesei

An extracellular β-galactosidase from Trichoderma reesei was crystallized from sodium cacodylate buffer using polyethylene glycol (PEG) as a precipant. Crystals grown by homogenous streak-seeding belonged to space group P1, with unit-cell parameters a = 67.3, b = 69.1, c = 81.5 Å, α = 109.1, β = 97.3, γ = 114.5°. The crystals diffracted to 1.8 Å resolution using a rotating-anode generator and to 1.2 Å resolution using a synchrotron source. On the basis of the Matthews coefficient (V_M = 3.16 ų Da⁻¹), one molecule is estimated to be present in the asymmetric unit. The aim of the determination of the crystal structure is to increase the understanding of this industrially significant enzyme.