Medium temperature, 310 K, provides single crystals of orotate phosphoribosyltransferase from Thermus thermophilus

Crystallization of orotate phosphoribosyltransferase from a thermophilic or ganism, Thermus thermophilus, was achieved using the hanging-drop vapour-di ffusion method coupled with a macroseeding starter. Small needle-like micro crystals were grown in a fresh protein solution in the presence of 2-methyl -2,4-pentanediol at 298 K or below Although these normal temperature condit ions caused stacking crystallization, an increase of temperature to 310 K p ermitted crystal growth. This was because of increased enzyme solubility at the higher temperature. The crystal was found to belong to the monoclinic space group P2(1) with unit-cell parameters a = 44.4, b = 59.6, c = 67.8 An gstrom and beta = 98.3 degrees.