Purification, characterization and crystallization of thermostable anthranilate phosphoribosyltransferase from Sulfolobus solfataricus.
Anthranilate phosphoribosyltransferase (TrpD; EC 184.108.40.206) from the hyperthermophilic archaeon Sulfolobus solfataricus (ssTrpD) was expressed in Escherichia coli, purified and crystallized. Analytical gel permeation chromatography revealed a homodimeric composition of the enzyme. The steady-state kinetic characteristics suggest tight binding of the substrate anthranilic acid and efficient catalysis at the physiological growth temperature of S. solfataricus. Crystals of ssTrpD diffract to better than 2.6 A resolution and preliminary X-ray characterization was carried out. The crystals are suitable for structure determination.