Purification and crystallization of fumarase C from Escherichia coli

Fumarase C purified from Escherichia coli has been crystallized in the presence of polyethylene glycol in both a citrate buffer at pH 5.3 and a 3-(4-morpholino)-propanesulfonic acid buffer at pH 7.5 yielding two crystal forms. An orthorhombic C222(1) form was obtained in citrate at pH 5.3 and an orthorhombic I222 form was obtained in 3-(4-morpholino)-propanesulfonic acid (pH 7.5). Complete native data sets have been collected on both crystal forms: the C222(1) form is complete to 2.10 A and the I222 form is complete to 2.20 A.