Protein smoothened (SMO) is a 787-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q99835.
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The mean pLDDT of this model is 72.8 (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 | 42% |
| 70 to 90 | Confident: backbone generally right | 19% |
| 50 to 70 | Low: treat with caution | 12% |
| Below 50 | Very low: often disordered regions | 28% |
What pLDDT means and how to read it
G protein-coupled receptor, which transduces the smoothened signaling pathway (PubMed:19592253, PubMed:27437577, PubMed:28344083, PubMed:31168089, PubMed:32929279, PubMed:36202993). Activated by cholesterol in response to hedgehog (DHH, IHH or SHH) morphogens (PubMed:27437577, PubMed:28344083, PubMed:32929279). In absence of hedgehog, SMO is inactivated by patched protein (PTCH1 or PTCH2), which prevents SMO access to cholesterol (PubMed:28344083). In response to hedgehog-binding to pathched, inhibition is relieved, promoting SMO translocation to primary cilium and activation by cholesterol: cholesterol causes a conformation change that triggers signaling via G protein G(i), mediating…
Homodimer (PubMed:23636324, PubMed:27437577). Interacts (via PKI motif) with protein kinase A catalytic subunit PRKACA; interacts with free PRKACA subunits and the interaction leads to sequestration of PRKACA at the membrane, preventing PRKACA-mediated phosphorylation of GLI transcription factors (PubMed:36202993, PubMed:39138140). Interacts with ARRB1 and ARRB2; promoting its localization to…
Cell membrane, Cell projection, cilium membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 4JKV | X-ray | 2.45 Å | A/B=190-555 |
| 4QIN | X-ray | 2.6 Å | A=190-433, A=441-555 |
| 4QIM | X-ray | 2.61 Å | A=190-433, A=441-555 |
| 4N4W | X-ray | 2.8 Å | A=190-555 |
| 5V56 | X-ray | 2.9 Å | A/B=53-437, A/B=444-558 |
| 5V57 | X-ray | 3.0 Å | A/B=58-437, A/B=444-558 |
| 7ZI0 | X-ray | 3.0 Å | A/B=32-428, A/B=443-555 |
| 6XBM | EM | 3.15 Å | R=1-644 |
| 4O9R | X-ray | 3.2 Å | A=190-433, A=441-555 |
| 5L7D | X-ray | 3.2 Å | A/B=32-428, A/B=443-555 |
| 6XBK | EM | 3.24 Å | R=1-644 |
| 5L7I | X-ray | 3.3 Å | A/B=32-428, A/B=443-555 |
| 6XBJ | EM | 3.88 Å | R=1-644 |
| 6OT0 | EM | 3.9 Å | R=1-555 |
| 6XBL | EM | 3.9 Å | R=1-644 |
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