Tight Chemomechanical Coupling of the F₁ Motor Relies on Structural Stability.

ABSTRACT: The F₁ motor is a rotating molecular motor that ensures a tight chemomechanical coupling between ATP hydrolysis/synthesis reactions and rotation steps. However, the mechanism underlying this tight coupling remains to be elucidated. In this study, we used electrorotation in single-molecule experiments using an F₁βE190D mutant to demonstrate that the stall torque was significantly smaller than the wild-type F₁, indicating a loose coupling of this mutant, despite showing similar stepping torque as the wild-type. Experiments on the ATPase activity after heat treatment and gel filtration of the α₃β₃-subcomplex revealed the unstable structure of the βE190D mutant. Our results suggest that the tight chemomechanical coupling of the F₁

SUBMITTER: Tanaka M 

PROVIDER: S-EPMC7335906 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature