Survival motor neuron protein (SMN1) is a 294-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q16637.
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The mean pLDDT of this model is 66.9 (low 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 | 25% |
| 70 to 90 | Confident: backbone generally right | 17% |
| 50 to 70 | Low: treat with caution | 31% |
| Below 50 | Very low: often disordered regions | 28% |
What pLDDT means and how to read it
The SMN complex catalyzes the assembly of small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome, and thereby plays an important role in the splicing of cellular pre-mRNAs (PubMed:18984161, PubMed:9845364). Most spliceosomal snRNPs contain a common set of Sm proteins SNRPB, SNRPD1, SNRPD2, SNRPD3, SNRPE, SNRPF and SNRPG that assemble in a heptameric protein ring on the Sm site of the small nuclear RNA to form the core snRNP (Sm core) (PubMed:18984161). In the cytosol, the Sm proteins SNRPD1, SNRPD2, SNRPE, SNRPF and SNRPG are trapped in an inactive 6S pICln-Sm complex by the chaperone CLNS1A that controls the assembly of the core snRNP (PubMed:18984161). To…
Homooligomer; may form higher order homooligomers in the dimer to octamer range (PubMed:10500148, PubMed:14715275, PubMed:17178713, PubMed:21816274, PubMed:23022347, PubMed:26092730). Part of the core SMN complex that contains SMN1, GEMIN2/SIP1, DDX20/GEMIN3, GEMIN4, GEMIN5, GEMIN6, GEMIN7, GEMIN8 and STRAP/UNRIP (PubMed:17178713, PubMed:9323129). Part of the SMN-Sm complex that contains SMN1,…
Nucleus, gem, Nucleus, Cajal body, Cytoplasm, Cytoplasmic granule, Perikaryon, Cell projection, neuron projection, Cell projection, axon, Cytoplasm, myofibril, sarcomere, Z line
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 7W2P | X-ray | 1.15 Å | A=82-147 |
| 4QQ6 | X-ray | 1.75 Å | A=82-147 |
| 1MHN | X-ray | 1.8 Å | A=89-147 |
| 7W30 | X-ray | 1.8 Å | A/B/C/D=82-147 |
| 4GLI | X-ray | 1.9 Å | A=263-294 |
| 5XJL | X-ray | 2.5 Å | M=26-62 |
| 5XJU | X-ray | 2.58 Å | M=26-62 |
| 5XJT | X-ray | 2.92 Å | M=26-62 |
| 5XJR | X-ray | 3.12 Å | M=26-62 |
| 5XJQ | X-ray | 3.28 Å | M=26-62 |
| 5XJS | X-ray | 3.38 Å | M=26-62 |
| 1G5V | NMR | A=82-169 | |
| 2LEH | NMR | B=26-51 | |
| 4A4E | NMR | A=84-147 | |
| 4A4G | NMR | A=84-147 |
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