Squalene synthase (FDFT1) is a 417-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P37268.
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The mean pLDDT of this model is 89.1 (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 | 73% |
| 70 to 90 | Confident: backbone generally right | 11% |
| 50 to 70 | Low: treat with caution | 13% |
| Below 50 | Very low: often disordered regions | 3% |
What pLDDT means and how to read it
Catalyzes the condensation of 2 farnesyl pyrophosphate (FPP) moieties to form squalene. Proceeds in two distinct steps. In the first half-reaction, two molecules of FPP react to form the stable presqualene diphosphate intermediate (PSQPP), with concomitant release of a proton and a molecule of inorganic diphosphate. In the second half-reaction, PSQPP undergoes heterolysis, isomerization, and reduction with NADPH or NADH to form squalene. It is the first committed enzyme of the sterol biosynthesis pathway
Endoplasmic reticulum membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 6PYW | X-ray | 1.38 Å | C=280-288 |
| 6PYJ | X-ray | 1.44 Å | C=280-288 |
| 6PYV | X-ray | 1.45 Å | C=280-288 |
| 3VJ8 | X-ray | 1.52 Å | A=31-370 |
| 3VJ9 | X-ray | 1.52 Å | A=31-370 |
| 6PZ5 | X-ray | 1.53 Å | C=280-288 |
| 3WEG | X-ray | 1.75 Å | A=31-370 |
| 3VJA | X-ray | 1.76 Å | A/B=31-370 |
| 3WEI | X-ray | 1.79 Å | A=31-370 |
| 3V66 | X-ray | 1.8 Å | A=31-370 |
| 3WEK | X-ray | 1.85 Å | A=31-370 |
| 3WEH | X-ray | 1.87 Å | A=31-370 |
| 3VJC | X-ray | 1.89 Å | A/B/C/D/E/F=31-370 |
| 3ASX | X-ray | 2.0 Å | A=31-370 |
| 3Q2Z | X-ray | 2.0 Å | A=31-370 |
| 3Q30 | X-ray | 2.0 Å | A=31-370 |
| 3WEJ | X-ray | 2.0 Å | A=31-370 |
| 8WTQ | X-ray | 2.0 Å | A=31-370 |
| 8WTR | X-ray | 2.0 Å | A=31-370 |
| 3VJB | X-ray | 2.05 Å | A/B/C/D/E/F=31-370 |
Showing 20 of 32 experimental structures (best resolution first).
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