AP-3 complex subunit sigma-1 (AP3S1) is a 193-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q92572.
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The mean pLDDT of this model is 84.8 (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 | 65% |
| 70 to 90 | Confident: backbone generally right | 14% |
| 50 to 70 | Low: treat with caution | 14% |
| Below 50 | Very low: often disordered regions | 7% |
What pLDDT means and how to read it
Part of the AP-3 complex, an adaptor-related complex which is not clathrin-associated. The complex is associated with the Golgi region as well as more peripheral structures. It facilitates the budding of vesicles from the Golgi membrane and may be directly involved in trafficking to lysosomes. In concert with the BLOC-1 complex, AP-3 is required to target cargos into vesicles assembled at cell bodies for delivery into neurites and nerve terminals
Adaptor protein complex 3 (AP-3) is a heterotetramer composed of two large adaptins (delta-type subunit AP3D1 and beta-type subunit AP3B1 or AP3B2), a medium adaptin (mu-type subunit AP3M1 or AP3M2) and a small adaptin (sigma-type subunit APS1 or AP3S2). Interacts with AGAP1. AP-3 associates with the BLOC-1 complex (By similarity)
Golgi apparatus, Cytoplasmic vesicle membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 9C5C | EM | 3.6 Å | S=1-151 |
| 9C59 | EM | 4.3 Å | S/s=1-193 |
| 9C5B | EM | 4.5 Å | S=1-193 |
| 9C58 | EM | 4.7 Å | S=1-193 |
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