Crystallization and preliminary X-ray diffraction analysis of a novel GH120 β-xylosidase (XylC) from Thermoanaerobacterium saccharolyticum JW/SL-YS485.

Xylosidases hydrolyze xylopolymers at the nonreducing end to free xylose units. The β-xylosidase (XylC) from Thermoanaerobacterium saccharolyticum JW/SL-YS485 was expressed in Escherichia coli and the recombinant protein was purified and crystallized. A BLASTP search with the XylC protein sequence showed that no similar structure had previously been solved. XylC was classified as a member of the new glycoside hydrolase family GH120 according to the CAZy website (http://www.cazy.org/). Crystals belonging to the monoclinic space group P2(1), with unit-cell parameters a = 88.36, b = 202.20, c = 99.87 Å, β = 99.04°, were obtained by the sitting-drop vapour-diffusion method and diffracted to 2.2 Å resolution. Structure determination using MIR and MAD methods is in progress.