Provided are a protein complex having the F.sub.0F.sub.1-ATPase activity; a DNA encoding the protein complex; a method for producing the protein complex, using the DNA; and a method for producing nucleoside 5'-triphosphate using the protein. The present invention further provides a recombinant DNA with the DNA inserted therein; a transformant carrying the recombinant DNA; and a method for producing a protein complex, using the transformant.