Activation of Bacterial F-ATPase by LDAO: Deciphering the Molecular Mechanism.

Proton FF ATP synthase catalyzes the formation of ATP from ADP and inorganic phosphate coupled with transmembrane proton transfer using the energy of the protonmotive force (). As decreases, the direction of the reaction is reversed and the enzyme generates , transferring protons across the membrane using the energy of ATP hydrolysis. ATPase activity of the enzyme can be suppressed by ADP in a non-competitive manner (ADP-inhibition), and in a number of bacteria, it can be inhibited by conformational changes in the regulatory C-terminal domain of the ε subunit.

Heterogeneity of Starved Yeast Cells in IF Levels Suggests the Role of This Protein .

In mitochondria, a small protein IF suppresses the hydrolytic activity of ATP synthase and presumably prevents excessive ATP hydrolysis under conditions of energy deprivation. In yeast , IF homologs are encoded by two paralogous genes: and . expression is known to aggravate the deleterious effects of mitochondrial DNA (mtDNA) depletion.

Attenuated ADP-inhibition of FF ATPase mitigates manifestations of mitochondrial dysfunction in yeast.

Proton-translocating FF ATP synthase (F-ATPase) couples ATP synthesis or hydrolysis to transmembrane proton transport in bacteria, chloroplasts, and mitochondria. The primary function of the mitochondrial FF is ATP synthesis driven by protonmotive force (pmf) generated by the respiratory chain. However, when pmf is low or absent (e.