Mothers against decapentaplegic homolog 4 (SMAD4) is a 552-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q13485.
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The mean pLDDT of this model is 73.4 (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 | 50% |
| 70 to 90 | Confident: backbone generally right | 13% |
| 50 to 70 | Low: treat with caution | 5% |
| Below 50 | Very low: often disordered regions | 33% |
What pLDDT means and how to read it
In muscle physiology, plays a central role in the balance between atrophy and hypertrophy. When recruited by MSTN, promotes atrophy response via phosphorylated SMAD2/4. MSTN decrease causes SMAD4 release and subsequent recruitment by the BMP pathway to promote hypertrophy via phosphorylated SMAD1/5/8. Acts synergistically with SMAD1 and YY1 in bone morphogenetic protein (BMP)-mediated cardiac-specific gene expression. Binds to SMAD binding elements (SBEs) (5'-GTCT/AGAC-3') within BMP response element (BMPRE) of cardiac activating regions (By similarity). Common SMAD (co-SMAD) is the coactivator and mediator of signal transduction by TGF-beta (transforming growth factor). Component of the…
Monomer; in the absence of TGF-beta activation (PubMed:9670020). Heterotrimer; on TGF-beta activation (PubMed:15799969). Heterotrimer composed of two molecules of a C-terminally phosphorylated R-SMAD molecule, SMAD2 or SMAD3, and one molecule of SMAD4 to form the transcriptional active SMAD2/SMAD3-SMAD4 complex (PubMed:15350224, PubMed:15799969). Found in a ternary complex composed of SMAD4,…
Cytoplasm, Nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 6YIC | X-ray | 1.6 Å | P=398-406 |
| 5MEY | X-ray | 2.05 Å | A=10-140 |
| 1YGS | X-ray | 2.1 Å | A=319-552 |
| 5UWU | X-ray | 2.24 Å | D=133-149 |
| 1U7F | X-ray | 2.6 Å | B=314-552 |
| 5C4V | X-ray | 2.6 Å | A/C/E=314-549 |
| 1DD1 | X-ray | 2.62 Å | A/B/C=285-552 |
| 1U7V | X-ray | 2.7 Å | B=314-549 |
| 1MR1 | X-ray | 2.85 Å | A/B=319-552 |
| 5MEZ | X-ray | 2.98 Å | A/B=10-140 |
| 1G88 | X-ray | 3.0 Å | A/B/C=285-552 |
| 5MF0 | X-ray | 3.03 Å | A/B=10-140 |
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