Phosphorylase b kinase regulatory subunit beta (PHKB) is a 1093-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q93100.
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The mean pLDDT of this model is 86.8 (confident overall). pLDDT is AlphaFold's per-residue confidence score from 0 to 100. In MolViewer, choose the B-factor color scheme to color the model by pLDDT, because AlphaFold stores it in the B-factor column.
| pLDDT band | Meaning | Share of residues |
|---|---|---|
| Above 90 | Very high: backbone and side chains are usually accurate | 64% |
| 70 to 90 | Confident: backbone generally right | 25% |
| 50 to 70 | Low: treat with caution | 5% |
| Below 50 | Very low: often disordered regions | 6% |
What pLDDT means and how to read it
Phosphorylase b kinase catalyzes the phosphorylation of serine in certain substrates, including troponin I. The beta chain acts as a regulatory unit and modulates the activity of the holoenzyme in response to phosphorylation
Hexadecamer of 4 heterotetramers, each composed of alpha, beta, gamma, and delta subunits. Alpha (PHKA1 or PHKA2) and beta (PHKB) are regulatory subunits, gamma (PHKG1 or PHKG2) is the catalytic subunit, and delta is calmodulin
Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 8XYA | EM | 2.7 Å | B=1-1093 |
| 8JFK | EM | 2.9 Å | B/F/J/N=1-1093 |
| 8JFL | EM | 2.9 Å | B/F/J/N=1-1093 |
| 8Z5P | EM | 3.41 Å | B/F=1-1093 |
| 8Z5T | EM | 3.74 Å | B/F/J/N=1-1093 |
| 8Z5Q | EM | 4.24 Å | B/F/J/N=1-1093 |
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