Crystallization and preliminary crystallographic analysis of a native chitinase from the fungal pathogen Aspergillus fumigatus YJ-407.

Abstract

Chitinase hydrolyzes chitin, a linear polymer of beta-1,4-linked N-acetylglucosamine (NAG), and plays a variety of roles in the biological world. In addition to endo- and exo-hydrolytic activities, transglycosyl activity has also been observed in the extracellular chitinase (afCHI) from the airborne saprophytic fungi Aspergillus fumigatus YJ-407. Crystals of this native chitinase have been grown at 291 K using PEG 3350 as a precipitant. The diffraction data from the crystal extend to 1.7 A resolution at BSRF, China. The crystal belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 95.7, b = 100.5, c = 134.3 A. The presence of two molecules per asymmetric unit gives a crystal volume per protein mass (V(M)) of 3.6 A(3) Da(-1) and a solvent content of 65% by volume. A full set of X-ray diffraction data was collected to 2.1 A resolution.