Crystallization and preliminary X-ray analysis of a novel Trichoderma reesei xylanase IV belonging to glycoside hydrolase family 5

Xylanase IV (XYN IV) is a new recently characterized xylanase from Trichoderma reesei. It is able to degrade several different xylans, mainly producing xylose. XYN IV has been crystallized by the hanging-drop vapour-diffusion method, using PEG 6000 as a precipitant. The crystals belong to the orthorhombic space group P2₁2₁2₁, with unit-cell parameters a = 86.3, b = 137.5, c = 196.1 Å, [alpha] = [beta] = [gamma] = 90°. Assuming a molecular weight of 50.3 kDa, the V_M values indicate there to be four XYN IV monomers in an asymmetric unit and the solvent content of the crystals to be 57%. Based on dynamic light-scattering measurements, XYN IV is a dimer in solution. A native data set to 2.8 Å resolution has been collected at a home laboratory and a data set to 2.2 Å resolution has been collected using synchrotron radiation.