Crystallization and preliminary X-ray diffraction analysis of a class V chitinase from Nicotiana tabacum.

The plant chitinases, which have been implicated in self-defence against pathogens, are divided into at least five classes (classes I, II, III, IV and V). Although the crystal structures of several plant chitinases have been solved, no crystal structure of a class V chitinase has been reported to date. Here, the crystallization of Nicotiana tabacum class V chitinase (NtChiV) using the vapour-diffusion method is reported. The NtChiV crystals diffracted to 1.2 Å resolution using synchrotron radiation at the Photon Factory. The crystals belonged to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a=62.4, b=120.3, c=51.9 Å. The asymmetric unit of the crystals is expected to contain one molecule.