ATP Synthesis by Rotary Catalysis (Nobel lecture).

The cyclic modulation of nucleotide-binding properties of the three catalytic β subunits by a series of conformational changes was an attractive explanation for the postulated binding change mechanism of ATP synthase. In the crystal structure of the catalytic F1 domain of this enzyme there is indeed a complex made up of three α subunits and three β subunits arranged in alternation around a central α-helical segment of the γ subunit. This complex is asymmetric owing to the different conformations of the β subunits. The change in conformation is brought about by rotation of the rigid yet curved segment, which has meanwhile been proven experimentally.