Crystallization and preliminary X-ray crystallographic analysis of quinolinate phosphoribosyltransferase from porcine kidney in complex with nicotinate mononucleotide

Quinolinate phosphoribosyltransferase (QAPRTase) is a key enzyme in NAD biosynthesis; it catalyzes the formation of nicotinate mononucleotide (NAMN) from quinolinate and 5-phosphoribosyl-1-pyrophosphate. In order to elucidate the mechanism of NAMN biosynthesis, crystals of Sus scrofa QAPRTase (Ss-QAPRTase) purified from porcine kidney in complex with NAMN were obtained and diffraction data were collected and processed to 2.1 angstrom resolution. The Ss-QAPRTase-NAMN cocrystals belonged to space group P321, with unit-cell parameters a = 119.1, b = 119.1, c = 93.7 angstrom, gamma = 120.0 degrees. The Matthews coefficient and the solvent content were estimated as 3.10 angstrom(3) Da(-1) and 60.3%, respectively, assuming the presence of two molecules in the asymmetric unit.