Gene

Quantum mechanics

Cell biology

Magnetic field

Neuroscience

Biology

Tetramer

Inhibitor protein

Inhibitory postsynaptic potential

Biochemistry

ATP synthase gamma subunit

Physics

Membrane

Chemiosmosis

Enzyme

V-ATPase

Protein subunit

Electrochemical gradient

Chemistry

Antiparallel (mathematics)

Biophysics

Adenosine triphosphate

ATP hydrolysis

ATPase

ATP synthase

Science

The mitochondrial adenosine triphosphate (ATP) synthase produces most of the ATP required by mammalian cells. We isolated porcine tetrameric ATP synthase and solved its structure at 6.2-angstrom resolution using a single-particle cryo-electron microscopy method. Two classical V-shaped ATP synthase dimers lie antiparallel to each other to form an H-shaped ATP synthase tetramer, as viewed from the matrix. ATP synthase inhibitory factor subunit 1 (IF1) is a well-known in vivo inhibitor of mammalian ATP synthase at low pH. Two IF1 dimers link two ATP synthase dimers, which is consistent with the ATP synthase tetramer adopting an inhibited state. Within the tetramer, we refined structures of intact ATP synthase in two different rotational conformations at 3.34- and 3.45-Å resolution.

Cryo-EM structure of the mammalian ATP synthase tetramer bound with inhibitory protein IF1