Crystallization and preliminary crystallographic investigation of porcine quinolinate phosphoribosyltransferase

Quinolinate phosphoribosyltransferase (QPRT), purified from hog liver, has been crystallized using PEG 8000 as the precipitant. The crystals form long hexagonal rods in the space group P6₃22 with cell dimensions a = b = 121.7, c = 94.5 Å. Based on the unit-cell dimensions and the calculated molecular mass of 33 500 Da, the Matthews coefficient suggests one molecule per asymmetric unit (V_m = 3.45 ų Da⁻¹; 64% solvent). Three native data sets were collected to a resolution of 2.5 Å and merged to provide a set that is 94.7% complete, with an R_sym value of 9.6%.