The isolated alpha3beta3 stator ring of F1-ATPase intrinsically propagates conformational states counterclockwise with 83% efficiency upon ATP hydrolysis, demonstrating rotary catalysis without a rotor.
F1 is an adenosine triphosphate (ATP)–driven motor in which three torque-generating β subunits in the α3β3 stator ring sequentially undergo conformational changes upon ATP hydrolysis to rotate the central shaft γ unidirectionally. Although extensive experimental and theoretical work has been done, the structural basis of cooperative torque generation to realize the unidirectional rotation remains elusive. We used high-speed atomic force microscopy to show that the rotorless F1 still “rotates”; in the isolated α3β3 stator ring, the three β subunits cyclically propagate conformational states in the counterclockwise direction, similar to the rotary shaft rotation in F1. The structural basis of unidirectionality is programmed in the stator ring. These findings have implications for cooperative interplay between subunits in other hexameric ATPases.
Uchihashi et al. (Fri,) reported a other. ATP (Adenosine triphosphate) vs. Nucleotide-free or AMPPNP was evaluated on Counterclockwise propagation of conformational states (rotation efficiency). The isolated alpha3beta3 stator ring of F1-ATPase intrinsically propagates conformational states counterclockwise with 83% efficiency upon ATP hydrolysis, demonstrating rotary catalysis without a rotor.