Crystallization and preliminary X-ray diffraction studies of a rice cysteine proteinase inhibitor, Oryzacystatin-I.

Oryzacystatin-I from rice seeds was overexpressed in Escherichia coli, purified, and crystallized by the sitting-drop vapor diffusion method. Crystals obtained with 2-methyl-2,4-pentanediol as a precipitant exhibited space group I4122, with unit cell parameters of a = b = 100.0 A, c = 54.2 A, and diffracted up to 2.8 A resolution at 100 K. The crystals have one molecule per asymmetric unit.