The energy transmission in ATP synthase: From the gamma-c rotor to the alpha(3)beta(3) oligomer fixed by OSCP-b stator via the beta DELSEED sequence

ATP synthase (F0F1) is driven by an electrochemical potential of H+ (Delta mu H+). F0F1 is composed of an ion-conducting portion (F-0) and a catalytic portion (F-1). The subunit composition of F-l is alpha(3) beta(3) gamma delta epsilon. The active alpha(3) beta(3) oligomer, characterized by X-ray crystallography, has been obtained only from thermophilic F-1 (TF1). We proposed in 1984 that ATP is released from the catalytic site (C site) by a conformational change induced by the beta DELSEED sequence via gamma delta epsilon-F-0. In fact, cross-linking of beta DELSEED to gamma stopped the ATP-driven rotation of gamma in the center of alpha(3) beta(3) The torque of the rotation is estimated to be 420 pN .Angstrom from the Delta mu H+ and H+-current through F0F1. The angular velocity to) of gamma is the rate-limiting step, because Delta mu H+ increased the V-max of H+ current through F-0, but not the K m(ATP) The rotational unit of F-0 (= ab(2)c(10)) is pi/5, while that in alpha(3) beta(3) is 2 pi/3. This difference is overcome by an analog-digital conversion via elasticity around beta DELSEED with a threshold to release ATP. The alpha beta distance at the C site is about 9.6 Angstrom (2,8-diN(3)-ATP), and tight Mg-ATP binding in (alpha(3) beta(3) gamma was shown by ESR. The rotational relaxation of TF1 is too rapid (phi = 100 nsec), but the rate of AT(D)P-induced conformational change of alpha(3) beta(3) measured with a synchrotron is close to omega. The ATP bound between the P-loop and beta E188 is released by the shift of beta DELSEED from gamma RGL. Considering the viscosity resistance and inertia of the free rotor (gamma-c), there may be a stator containing OSCP (=delta of TF1) and F-0-d to hold free rotation of alpha(3) beta(3).