First crystallization of a phosphoenolpyruvate carboxylase from Escherichia coli.

Two different forms of crystal for a phosphoenolpyruvate carboxylase from Escherichia coli were obtained by the hanging-drop vapor diffusion technique, using polyethylene glycol 4000 as precipitant. The hexagonal crystal in space group P6(2)22 (or P6(4)22) has cell dimensions of a = 131 A and c = 325 A, whereas the orthorhombic crystal in space group I222 has a = 119 A, b = 252 A and c = 83 A. A tetrameric molecule (396,244 Mr), a subunit of which contains 883 amino residues, has a crystallographic 2 symmetry in the hexagonal crystal or 222 symmetry in the orthorhombic crystal, respectively.