An intermediate step in the evolution of ATPases - The F1F 0-ATPase from Acetobacterium woodii contains F-type and V-type rotor subunits and is capable of ATP synthesis

Abstract

Previous preparations of the Na+ F1F0-ATP synthase solubilized by Triton X-100 lacked some of the membrane-embedded motor subunits [Reidlinger J & Müller V (1994) Eur J Biochem 233, 275-283]. To improve the subunit recovery, we revised our purification protocol. The ATP synthase was solubilized with dodecylmaltoside and further purified to apparent homogeneity by chromatographic techniques. The preparation contained, along with the F1 subunits, the entire membrane-embedded motor with the stator subunits a and b, and the heterooligomeric c ring, which contained the V 1V0-like subunit c1 and the F1F 0-like subunits c2 and c3. After incorporation into liposomes, ATP synthesis could be driven by an electrochemical sodium ion potential or a potassium ion diffusion potential, but not by a sodium ion potential. This is the first demonstration that an ATPase with a V 0-F0 hybrid motor is capable of ATP synthesis. © 2007 The Authors.