Crystallization and crystal data of monellin.

Crystals of monellin, a sweet protein from Dioscoreophyllum cumminsii, were grown by vapor diffusion of 20% ethanol into buffered protein solution. The crystals are orthorhombic, belonging to space group P2(1)2(1)2, with a = 54.4 A, b = 113.0 A, c = 40.8 A, and V = 250,300 A(3). The asymmetric unit contains two complete molecules of monellin. The diffraction pattern of this crystal form extends to at least 2.5 A, indicating that x-ray structural analysis is possible to near-atomic resolution.