ATPsyntaz

ATP synthase, also commonly called ATP synthetase, is an essential enzyme complex that catalyzes the production of ATP from adenosine diphosphate (ADP) and inorganic phosphate (Pi). It couples this synthesis to the proton motive force generated by electron transport chains across membranes, forming the primary mechanism by which cells convert energy stored in gradients into usable chemical energy. The enzyme is widespread, occurring in the inner membranes of mitochondria and chloroplasts in eukaryotes and in the plasma membranes of many bacteria and archaea.

Two major forms exist. F-type ATP synthases (F-ATP synthases) synthesize ATP using a proton gradient and are found in mitochondria, chloroplasts, and many bacteria. V-type ATPases (V-ATPases) hydrolyze ATP to pump protons and regulate cellular pH, though some organisms can operate in reverse to generate ATP under certain conditions.

Structure and mechanism. The enzyme comprises a membrane-embedded sector called F0 and a soluble catalytic sector called F1. Protons moving through F0 drive rotation of the c-ring and the attached central stalk, which in turn induces conformational changes in the three beta subunits of F1 to synthesize ATP from ADP and Pi. The system is a rotary machine; it can also operate in reverse, hydrolyzing ATP to pump protons when the proton gradient is weak.

Discovery and significance. The rotary mechanism and subunit architecture were elucidated in the late 20th century. Paul D. Boyer and John E. Walker advanced the understanding of ATP synthase’s mechanism, and Jens C. Skou contributed to broader work on ATP-driven pumps. They were awarded the Nobel Prize in Chemistry in 1997 for insights into these energy-converting enzymes. ATP synthase is a central component of cellular energy metabolism and a target of research in bioenergetics and medicine.