Crystallization and preliminary diffraction analysis of the catalytic domain of major extracellular endoglucanase from Xanthomonas campestris pv. campestris

Cellulases, such as endoglucanases, exoglucanases and β‐glucosidases, are important enzymes used in the process of enzymatic hydrolysis of plant biomass. The bacteria Xanthomonas campestris pv. campestris expresses a large number of hydrolases and the major endoglucanase (XccEG), a member of glycoside hydrolase family 5 (GH5), is the most strongly secreted extracellularly. In this work, the native XccEG was purified from the extracellular extract and crystallization assays were performed on its catalytic domain. A complete data set was collected on an in‐house X‐ray source. The crystal diffracted to 2.7 Å resolution and belonged to space group C2, with unit‐cell parameters a = 174.66, b = 141.53, c = 108.00 Å, β = 110.49°. The Matthews coefficient suggests a solvent content of 70.1% and the presence of four protein subunits in the asymmetric unit.