Overproduction and Preliminary X-Ray Characterization of Aspartate Aminotransferase from Escherichia coli

Abstract

The aspartate aminotransferase of Escherichia coli was overproduced in cells after genetic manipulation, and was crystallized from a polyethylene glycol solution, pH 7.0. The crystals obtained were of good quality and had diffractions extending beyond 2.4 Å. The space group and unit cell dimensions were determined with a precession camera and a four-circle diffractometer to be C222₁ and a = 157.1 Å, b = 85.5 Å, and c = 79.7 Å, respectively. Only one protein subunit is contained in an asymmetric unit.