Crystallization and preliminary X-ray diffraction data of the second and archaebacterial-type aspartyl-tRNA synthetase from Thermus thermophilus

The archaebacterial-type aspartyl-tRNA synthetase (AspRS2) from the thermop hilic eubacterium Thermus thermophilus was crystallized using the hanging-d rop vapour-diffusion method. Crystals grew at pH 9.5 in the presence of PEG 8000 and NaCl. A native diffraction data set has been collected at 2.5 Ang strom resolution using synchrotron radiation and cryocooling. Crystals belo ng to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 57.3, b = 121.9, c = 166.9 Angstrom and VM = 3.03 Angstrom (3) Da(-1). There is one dimer of M-r 96 000 per asymmetric unit. A molecular-replacem ent analysis gave solutions for the rotation and translation functions.