Purification, Crystallization and Preliminary X-ray Crystallographic Analysis of ATP-phosphoribosyltransferase from Escherichia Coli

ATP-phosphoribosyltransferase (ATP-PRT) from Escherichia coli has been purified and crystals were obtained by the vapour-diffusion method using sodium tartrate as a precipitant. Dynamic light scattering was used to assess conditions for the monodispersity of the enzyme. The crystals are trigonal, space group R32, with unit-cell parameters a = b = 133.6, c= 114.1 A (at 100 K), and diffract to 2.7 A on a synchrotron X-ray source. The asymmetric unit is likely to contain one molecule, corresponding to a packing density of 2.9 A3 Da(-1). A model for the quaternary structure is proposed based on the crystallographic symmetry.