Cullin-4B (CUL4B) is a 913-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q13620.
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The mean pLDDT of this model is 78.5 (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 | 59% |
| 70 to 90 | Confident: backbone generally right | 16% |
| 50 to 70 | Low: treat with caution | 3% |
| Below 50 | Very low: often disordered regions | 21% |
What pLDDT means and how to read it
Core component of multiple cullin-RING-based E3 ubiquitin-protein ligase complexes which mediate the ubiquitination and subsequent proteasomal degradation of target proteins (PubMed:14578910, PubMed:16322693, PubMed:16678110, PubMed:18593899, PubMed:22118460, PubMed:29779948, PubMed:30166453, PubMed:33854232, PubMed:33854239, PubMed:25970626). The functional specificity of the E3 ubiquitin-protein ligase complex depends on the variable substrate recognition subunit (PubMed:14578910, PubMed:16678110, PubMed:18593899, PubMed:22118460, PubMed:29779948). CUL4B may act within the complex as a scaffold protein, contributing to catalysis through positioning of the substrate and the…
Component of multiple DCX (DDB1-CUL4-X-box) E3 ubiquitin-protein ligase complexes that seem to be formed of DDB1, CUL4A or CUL4B, RBX1 and a variable substrate recognition component which seems to belong to a protein family described as DCAF (Ddb1- and Cul4-associated factor) or CDW (CUL4-DDB1-associated WD40-repeat) proteins (PubMed:10230407, PubMed:16678110, PubMed:17041588, PubMed:18593899).…
Cytoplasm, Nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 4A64 | X-ray | 2.57 Å | A/B/C/D=206-557 |
| 8EI1 | X-ray | 2.89 Å | A/B/C/D=206-557 |
| 4A0C | X-ray | 3.8 Å | C/E=192-913 |
| 4A0L | X-ray | 7.4 Å | E/H=192-913 |
| 2DO7 | NMR | A=826-913 |
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