Crystallization of thioesterase II from Escherichia coli

X-ray quality single crystals of the Escherichia coli thioesterase II have been obtained. The protein used for crystallization was overexpressed in parent organism. The crystals are orthorhombic, space group C222(1) with axial lengths a = 99.0 A, b = 121.1 A, c = 166.6 A. A complete homotetramer (120,000 Da) of four polypeptide chains, each 286 residues long, occupies the asymmetric unit. The diffraction pattern extends to approximately 2.4 A resolution using CuK alpha radiation from a rotating anode source. The elucidation of the three-dimensional structure of this unusual bacterial thioesterase will provide basis for the analysis of its unique catalytic mechanism and substrate specificity.