Crystallization and preliminary X-ray diffraction analysis of a cytochromeP450 (CYP119) from Sulfolobus solfataricus

CYP119 is a cytochrome P450 with a molecular weight of 43 kDa which has bee n isolated from the thermophilic archaeon Sulfolobus solfataricus. This enz yme is extremely stable to high temperature and high pressure. The first cr ystallization and preliminary crystallographic study of CYP119 is reported here. Crystals of CYP119 were obtained by the sitting-drop vapour-diffusion method using a precipitant solution containing 20%(w/v) PEG 4000 and 0.2 M sodium thiocyanate at pH 6.4. Using synchrotron radiation, the CYP119 crys tal diffracted to 1.84 Angstrom resolution. It belongs to the tetragonal sp ace group P4(3)2(1)2, with unit-cell parameters a = b = 86.17 (0.07), c = 2 21.11 (0.04) Angstrom, in which the numbers in parentheses describe the sta ndard deviations. Assuming two molecules of the CYP119 per asymmetric unit, the calculated molar volume (V-m) is 2.38 Angstrom(3) Da(-1). Bijvoet and dispersive anomalous difference Patterson maps show a clear peak correspond ing to the haem irons. The complete crystallographically defined structure is currently in progress using MIR (multiple isomorphous replacement) and M AD (multiwavelength anomalous diffraction) techniques.