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.