F₀ and F₁ parts of ATP synthases from Clostridium thermoautotrophicum and Escherichia coli are not functionally compatible

F1-stripped membrane vesicles from Clostridium thermoautotrophicum and Escherichia coli were reconstituted with F1-ATPases from both bacteria. Reconstituted F1F0-ATPase complexes were catalytically active, i.e. capable of hydrolyzing ATP. Homologous-type ATPase complexes having F0 and F1 parts of ATP synthases from the same origin were DCCD sensitive and supported ATP-driven enhancement of anilinonaphthalene sulfonate (ANS) fluorescence. Hybrid-type ATPase complexes having F0 and F1 parts of ATP synthases from different origins were neither DCCD sensitive nor did they support ATP-driven enhancement of ANS fluorescence. Analyzing these results it has been demonstrated that the F0 and F1 parts of ATP synthases of these two bacteria are not functionally compatible.