Structural evidence of a new catalytic intermediate in the pathway of ATP hydrolysis by F1-ATPase from bovine heart mitochondria.

ABSTRACT: The molecular description of the mechanism of F(1)-ATPase is based mainly on high-resolution structures of the enzyme from mitochondria, coupled with direct observations of rotation in bacterial enzymes. During hydrolysis of ATP, the rotor turns counterclockwise (as viewed from the membrane domain of the intact enzyme) in 120° steps. Because the rotor is asymmetric, at any moment the three catalytic sites are at different points in the catalytic cycle. In a "ground-state" structure of the bovine enzyme, one site (β(E)) is devoid of nucleotide and represents a state that has released the products of ATP hydrolysis. A second site (β(TP)) has bound the substrate, magnesium. ATP, in a precatalytic state, and in the third site (β(DP)), the substrate is about to undergo hydrolysis. Three success

SUBMITTER: Rees DM 

PROVIDER: S-EPMC3396519 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature