Crystallization of and preliminary crystallographic studies on an active-site mutant of pro-Tk-subtilisin from the hyperthermophilic archaeon Thermococcus kodakaraensis were performed. The crystal was grown at 277 K by the sitting-drop vapour-diffusion method. Native X-ray diffraction data were collected to 2.3 angstrom resolution using synchrotron radiation from station BL41XU at SPring-8. The crystal belongs to the orthorhombic space group I222, with unit-cell parameters a = 92.69, b = 121.78, c = 77.53 angstrom. Assuming the presence of one molecule per asymmetric unit, the Matthews coefficient V-M was calculated to be 2.6 angstrom(3) Da(-1) and the solvent content was 53.1%.
