Beyond binding change: the molecular mechanism of ATP hydrolysis by F₁-ATPase and its biochemical consequences.

ABSTRACT: F₁-ATPase is a universal multisubunit enzyme and the smallest-known motor that, fueled by the process of ATP hydrolysis, rotates in 120^o steps. A central question is how the elementary chemical steps occurring in the three catalytic sites are coupled to the mechanical rotation. Here, we performed cold chase promotion experiments and measured the rates and extents of hydrolysis of preloaded bound ATP and promoter ATP bound in the catalytic sites. We found that rotation was caused by the electrostatic free energy change associated with the ATP cleavage reaction followed by Pi release. The combination of these two processes occurs sequentially in two different catalytic sites on the enzyme, thereby driving the two rotational sub-steps of the 120^o rotation. The

SUBMITTER: Nath S 

PROVIDER: S-EPMC10266426 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature