Crystallization and preliminary X-ray analysis of PH1566, a putative ribosomal RNA-processing factor from the hyperthermophilic archaeon Pyrococcus horikoshii OT3

A putative ribosomal RNA-processing factor consisting of two KH domains from Pyrococcus horikoshii OT3 (PH1566; 25 kDa) was crystallized by the sitting-drop vapour-diffusion method using PEG 3000 as the precipitant. The crystals diffracted X-rays to beyond 2.0 Å resolution using a synchrotron-radiation source. The space group of the crystals was determined as primitive orthorhombic P2₁2₁2₁, with unit-cell parameters a = 45.9, b = 47.4, c = 95.7 Å. The crystals contain one molecule in the asymmetric unit (V_M = 2.5 Å³ Da^-1) and have a solvent content of 50%.