Actin, cytoplasmic 1 (ACTB) is a 375-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P60709.
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The mean pLDDT of this model is 95.2 (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 | 93% |
| 70 to 90 | Confident: backbone generally right | 5% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 1% |
What pLDDT means and how to read it
Actin is a highly conserved protein that polymerizes to produce filaments that form cross-linked networks in the cytoplasm of cells (PubMed:25255767, PubMed:29581253). Actin exists in both monomeric (G-actin) and polymeric (F-actin) forms, both forms playing key functions, such as cell motility and contraction (PubMed:29581253). In addition to their role in the cytoplasmic cytoskeleton, G- and F-actin also localize in the nucleus, and regulate gene transcription and motility and repair of damaged DNA (PubMed:29925947). Plays a role in the assembly of the gamma-tubulin ring complex (gTuRC), which regulates the minus-end nucleation of alpha-beta tubulin heterodimers that grow into…
Polymerization of globular actin (G-actin) leads to a structural filament (F-actin) in the form of a two-stranded helix (PubMed:16685646, PubMed:28604741). Each actin can bind to 4 others (PubMed:16685646, PubMed:28604741). Identified in a IGF2BP1-dependent mRNP granule complex containing untranslated mRNAs (PubMed:17289661). Component of the BAF complex, which includes at least actin (ACTB),…
Cytoplasm, cytoskeleton, Nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 6MBK | X-ray | 1.69 Å | Y/Z=66-80 |
| 6OX0 | X-ray | 1.75 Å | Y/Z=66-80 |
| 6WK2 | X-ray | 1.76 Å | C/Y=66-88 |
| 6MBJ | X-ray | 1.78 Å | Y/Z=66-80 |
| 6OX3 | X-ray | 1.78 Å | Y/Z=66-84 |
| 7W28 | X-ray | 1.79 Å | P=66-81 |
| 6WK1 | X-ray | 1.89 Å | Y/Z=66-88 |
| 6ICT | X-ray | 1.95 Å | E/G/H/I=66-88 |
| 6OX1 | X-ray | 1.95 Å | Y/Z=66-80 |
| 6V63 | X-ray | 2.02 Å | Y/Z=66-88 |
| 6OX2 | X-ray | 2.09 Å | Y/Z=66-80 |
| 6OX5 | X-ray | 2.1 Å | Y=66-83 |
| 6ICV | X-ray | 2.15 Å | C/D=66-88 |
| 9QEW | EM | 2.18 Å | A/B/C/D/E=2-375 |
| 6MBL | X-ray | 2.2 Å | Y=66-80 |
| 3D2U | X-ray | 2.21 Å | C/G=170-178 |
| 8OI8 | EM | 2.28 Å | A/B/C/D/E=1-375 |
| 6OX4 | X-ray | 2.29 Å | Y/Z=66-80 |
| 8OID | EM | 2.3 Å | A/B/C/D/E=1-375 |
| 9QFJ | EM | 2.31 Å | A/B/C/D/E=2-375 |
Showing 20 of 84 experimental structures (best resolution first).
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