| ATP5B — ATP Synthase Subunit Beta |
|---|
| Protein Name | ATP Synthase Subunit Beta |
| Gene | ATP5B |
| UniProt ID | P06576 |
| PDB ID | 1BM1, 2JDI |
| Molecular Weight | ~56 kDa |
| Subcellular Localization | Mitochondrial inner membrane (F1 sector) |
| Protein Family | ATP synthase alpha/beta chain family |
ATP5B (ATP Synthase Subunit Beta) is the catalytic beta subunit of mitochondrial ATP synthase (Complex V). This is the primary catalytic subunit responsible for the synthesis of ATP from ADP and inorganic phosphate using the proton gradient.
The F1 domain contains three alpha and three beta subunits arranged in a hexameric ring. The beta subunits are the main catalytic components.
ATP5B features:
- ~529 amino acids
- Molecular weight ~56 kDa
- Three catalytic sites
- Nucleotide binding domains
- Conformational flexibility essential for catalysis
- ADP + Pi → ATP catalysis
- Conformational changes drive ATP synthesis
- ~3 ATP per rotation of F1 domain
- Tight coupling to proton flow through F0
- Primary ATP producer in cells
- Maintains cellular energy status
- Essential for all energy-dependent processes
- Decreased ATP5B in AD brain
- Reduced ATP synthesis capacity
- Contributes to synaptic dysfunction
- Early metabolic defect in AD
- Mitochondrial impairment in PD neurons
- ATP deficit in dopaminergic cells
- Linked to PD genetic mutations
- ATP synthase deficiencies cause severe disease
- Leigh syndrome phenotype
- Multi-system involvement
- Brown et al., ATP synthase in AD (2014)
- Pedersen et al., ATP synthase and neurodegeneration (2007)