Formation in Vivo, Purification and Crystallization of a Complex of the γ and ε Subunits of the F 0F 1-ATPase of Escherichia coli

A complex comprising the ε subunit of Escherichia coli F 1-ATPase (ECF1-ATPase) and a glutathione-S-transferase γ subunit (of ECF 1-ATPase) fusion protein was formed in vivo and purified from cell extracts by binding to glutathione-agarose beads. The glutathione-S-transferase was released from the complex by digestion with thrombin and the γ/ε complex purified by cation-exchange chromatography. Crystals of the complex were grown by vapour diffusion using PEG8000as precipitant. The crystals are orthorhombic, space-group P 2 12 12 with a = 161·9 Å, b = 44·1 Å and c = 63·4 Å. The volume of the asymmetric unit is consistent with the presence of a complex of one γ subunit and one ε subunit.