Preliminary X-ray crystallographic study of methyltetrahydrofolate: corrinoid/iron sulfur protein methyltransferase from Clostridium thermoaceticum.

Methyltetrahydrofolate:corrinoid/iron sulfur protein methyltransferase from Clostridium thermoaceticum has been crystallized in two polymorphic forms and characterized by X-ray diffraction measurements. Form I displayed orthorhombic symmetry with a = 63.9, b = 53.8, c = 164.0 A. Form II also displayed orthorhombic symmetry with a = 63.5, b = 87.1, c = 117.9 A. Crystals of form I diffract to approximately. 3 A resolution; those of form II diffract to approximately 2.7 A.