Crystallization and preliminary X-ray crystallographic studies of the plant aspartic proteinase cardosin A

The plant aspartic proteinase cardosin A was crystallized using vapour diffusion. Crystals belong to the monoclinic space group C2, cell dimensions a = 116.9(2), b = 87.2(8), c = 81.3 (1) Angstrom, beta = 104.4 (4)degrees, and contain two molecules in the asymmetric unit related by a non-crystallographic twofold axis. Diffraction data were collected at room temperature with radiation from a synchrotron source up to 2.85 Angstrom resolution. When the crystals were flash cooled to 110 K in a nitrogen stream the same resolution limit could also be obtained on a rotating-anode source. Recently, synchrotron radiation together with hash cooling led to an improvement of the diffraction data to 1.72 Angstrom resolution.