Crystallization and preliminary X-ray crystallographic analysis of human quinolinate phosphoribosyltransferase

Quinolinate phosphoribosyltransferase (QPRTase) is a key NAD‐biosynthetic enzyme which catalyzes the transfer of quinolinic acid to 5‐phosphoribosyl‐1‐pyrophosphate, yielding nicotinic acid mononucleotide. Homo sapiens QPRTase (Hs‐QPRTase) appeared as a hexamer during purification and the protein was crystallized. Diffraction data were collected and processed at 2.8 Å resolution. Native Hs‐QPRTase crystals belonged to space group P21, with unit‐cell parameters a = 76.2, b = 137.1, c = 92.7 Å, β = 103.8°. Assuming the presence of six molecules in the asymmetric unit, the calculated Matthews coefficient is 2.46 Å3 Da−1, which corresponds to a solvent content of 49.9%.