Crystallization and preliminary X-ray study of saporin, a ribosome-inactivating protein from Saponaria officinalis.

ABSTRACT

Single crystals of the protein saporin isolated from the seeds of S. officinalis have been grown by the vapor-diffusion method using ammonium sulfate as precipitant. The crystals are tetragonal, space group P4122 (P4322), with cell dimensions a = b = 67.53 and c = 119. 67 A, and diffract to 2.0 A resolution on a rotating-anode X-ray source. The asymmetric unit contains one molecule, corresponding to a volume of the asymmetric unit per unit mass (Vm) of 2.38 A3 Da-1.