Structure and Mechanisms of F-Type ATP Synthases.
Annu Rev Biochem
; 88: 515-549, 2019 06 20.
Article
em En
| MEDLINE
| ID: mdl-30901262
ABSTRACT
F1Fo ATP synthases produce most of the ATP in the cell. F-type ATP synthases have been investigated for more than 50 years, but a full understanding of their molecular mechanisms has become possible only with the recent structures of complete, functionally competent complexes determined by electron cryo-microscopy (cryo-EM). High-resolution cryo-EM structures offer a wealth of unexpected new insights. The catalytic F1 head rotates with the central γ-subunit for the first part of each ATP-generating power stroke. Joint rotation is enabled by subunit δ/OSCP acting as a flexible hinge between F1 and the peripheral stalk. Subunit a conducts protons to and from the c-ring rotor through two conserved aqueous channels. The channels are separated by â¼6 Å in the hydrophobic core of Fo, resulting in a strong local field that generates torque to drive rotary catalysis in F1. The structure of the chloroplast F1Fo complex explains how ATPase activity is turned off at night by a redox switch. Structures of mitochondrial ATP synthase dimers indicate how they shape the inner membrane cristae. The new cryo-EM structures complete our picture of the ATP synthases and reveal the unique mechanism by which they transform an electrochemical membrane potential into biologically useful chemical energy.
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Base de dados:
MEDLINE
Assunto principal:
Trifosfato de Adenosina
/
ATPases Translocadoras de Prótons
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article