Crystallization and preliminary X-ray diffraction analysis of endoglucanase III from Trichoderma harzianum.

Endoglucanases are enzymes that hydrolyze cellulose and are important components of the cellulolytic complex. In contrast to other members of the complex, they cleave internal β-1,4-glycosidic bonds in the cellulose polymer, allowing cellulose to be used as an energy source. Since biomass is an important renewable source of energy, the structural and functional characterization of these enzymes is of interest. In this study, endoglucanase III from Trichoderma harzianum was produced in Pichia pastoris and purified. Crystals belonging to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 47.54, b = 55.57, c = 157.3 Å, were obtained by the sitting-drop vapour-diffusion method and an X-ray diffraction data set was collected to 2.07 Å resolution.