ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction...
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Transcript of ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction...
![Page 1: ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction from bovine heartfrom E. coli matrix inner mb cytosol.](https://reader036.fdocuments.us/reader036/viewer/2022062500/5697bfab1a28abf838c9b330/html5/thumbnails/1.jpg)
ATP synthase is a multi-subunit complex with membrane and matrix components
Cryo EM reconstruction
from bovine heart from E. coli
matrix
innermb
cytosol
innermb
Proton translocator
ATPase
periplasmIM space
![Page 2: ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction from bovine heartfrom E. coli matrix inner mb cytosol.](https://reader036.fdocuments.us/reader036/viewer/2022062500/5697bfab1a28abf838c9b330/html5/thumbnails/2.jpg)
ATP synthesis happens in the F1 complex
![Page 3: ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction from bovine heartfrom E. coli matrix inner mb cytosol.](https://reader036.fdocuments.us/reader036/viewer/2022062500/5697bfab1a28abf838c9b330/html5/thumbnails/3.jpg)
Unlike most enzymes, product release is the rate-determining step for ATP synthase
![Page 4: ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction from bovine heartfrom E. coli matrix inner mb cytosol.](https://reader036.fdocuments.us/reader036/viewer/2022062500/5697bfab1a28abf838c9b330/html5/thumbnails/4.jpg)
Figure 18-24
The “binding change” mechanism explains how rotational motion drives ATP synthesis
Rotation of the γ subunit induces sequential conformational changes in the α and β subunits. The conformations promote:
1. ADP and Pi binding (Loose or ADP conformation)
2. ATP formation (Tight or ATP conformation)
3. ATP release (Open or empty conformation)
![Page 5: ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction from bovine heartfrom E. coli matrix inner mb cytosol.](https://reader036.fdocuments.us/reader036/viewer/2022062500/5697bfab1a28abf838c9b330/html5/thumbnails/5.jpg)
Proton movement across the membrane spins the rotor and drives ATP synthesis
Rotor: Ring of c subunits plus γ and ε(The rotor rotates.)
Stator: α/β ring plus a, b2 and δ(The stator is stationary.)
Binding and release of 3 protons turns the rotor 120, resulting in the synthesis of one ATP
![Page 6: ATP synthase is a multi-subunit complex with membrane and matrix components Cryo EM reconstruction from bovine heartfrom E. coli matrix inner mb cytosol.](https://reader036.fdocuments.us/reader036/viewer/2022062500/5697bfab1a28abf838c9b330/html5/thumbnails/6.jpg)
Pi + H+
Transporters allow substrates and products of ATP synthesis to cross the inner mitochondrial membrane
Cytoplasm Matrix
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The electrochemical gradient provides the driving force for this transmembrane movement