Tubulin beta-2B chain (TUBB2B) is a 445-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q9BVA1.
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The mean pLDDT of this model is 92.0 (very high 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 | 83% |
| 70 to 90 | Confident: backbone generally right | 13% |
| 50 to 70 | Low: treat with caution | 3% |
| Below 50 | Very low: often disordered regions | 1% |
What pLDDT means and how to read it
Tubulin is the major constituent of microtubules, a cylinder consisting of laterally associated linear protofilaments composed of alpha- and beta-tubulin heterodimers (PubMed:23001566, PubMed:26732629, PubMed:28013290). Microtubules grow by the addition of GTP-tubulin dimers to the microtubule end, where a stabilizing cap forms. Below the cap, tubulin dimers are in GDP-bound state, owing to GTPase activity of alpha-tubulin. Plays a critical role in proper axon guidance in both central and peripheral axon tracts (PubMed:23001566). Implicated in neuronal migration (PubMed:19465910)
Dimer of alpha and beta chains (PubMed:23001566, PubMed:26732629, PubMed:28013290). A typical microtubule is a hollow water-filled tube with an outer diameter of 25 nm and an inner diameter of 15 nM. Alpha-beta heterodimers associate head-to-tail to form protofilaments running lengthwise along the microtubule wall with the beta-tubulin subunit facing the microtubule plus end conferring a…
Cytoplasm, cytoskeleton
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 9OX7 | EM | 2.69 Å | B/D/E/F=1-445 |
| 7ZCW | EM | 3.6 Å | B/F/G/H=1-445 |
| 6E7C | EM | 3.65 Å | B=1-426 |
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