Crystallization and X-ray diffraction measurements of a thermophilic archaeal recombinant amidase from Sulfolobus solfataricus MT4

Recombinant amidase is a 55.8 kDa enzyme from the thermophilic archaeon Sul folobus solfataricus MT4 that catalyses the hydrolysis of aliphatic amides of 2-6 C atoms as well as many aromatic amides. Single crystals of purified amidase were obtained by the hanging-drop method at 294 K. Diffraction dat a for the native protein (2.55 Angstrom resolution) and a putative derivati ve (2.20 Angstrom) have been collected at low temperature using synchrotron radiation. The crystals belong to the rhombohedral space group R3. Structu re determination by multiple isomorphous replacement is in progress. It is expected that structural information from this signatured thermostable amid ase will increase our knowledge of the molecular mechanisms employed to mai ntain high-temperature stability in thermophilic proteins.