Purification, crystallization and preliminary crystallographic analysis of a 4-thiouridine synthetase-RNA complex

The sulfurtransferase 4-thiouridine synthetase (ThiI) is involved in the ATP-dependent modification of U8 in tRNA. ThiI from Thermotoga maritima was cloned, overexpressed and purified. A complex comprising ThiI and a truncated tRNA was prepared and crystallized, and X-ray diffraction data were collected to a resolution of 3.5 Å. The crystals belonged to the orthorhombic space group P212121, with unit-cell parameters a = 102.9, b = 112.8, c = 132.8 Å.