α3β3 complex of thermophilic ATP synthase Catalysis without the γ-subunit

AbstractA complex of the α- and β-subunits of thermophilic ATP synthase showed about 25% of the ATPase activity of the αβγ complex. The α3β3 hexamer structure was analyzed by sedimentation (11.2 S) and gel filtration (310 kDa). Dilution of the αβ complex caused dissociation of the complex and rapid loss of ATPase activity which was restored by addition of the γ-subunit. A previous method using urea for isolating the subunits resulted in an αβ complex with lower activity than that prepared by over-expression of the genes. The αβ-ATP complex was formed from the αβ complex, ADP and Pi in the presence of dimethyl sulfoxide