Phosphoinositide 3-kinase regulatory subunit 4 (PIK3R4) is a 1358-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q99570.
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The mean pLDDT of this model is 78.1 (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 | 32% |
| 70 to 90 | Confident: backbone generally right | 46% |
| 50 to 70 | Low: treat with caution | 8% |
| Below 50 | Very low: often disordered regions | 14% |
What pLDDT means and how to read it
Regulatory subunit of the PI3K complex that mediates formation of phosphatidylinositol 3-phosphate; different complex forms are believed to play a role in multiple membrane trafficking pathways: PI3KC3-C1 is involved in initiation of autophagosomes and PI3KC3-C2 in maturation of autophagosomes and endocytosis. Involved in regulation of degradative endocytic trafficking and cytokinesis, probably in the context of PI3KC3-C2 (PubMed:20643123)
Component of the PI3K (PI3KC3/PI3K-III/class III phosphatidylinositol 3-kinase) complex the core of which is composed of the catalytic subunit PIK3C3, the regulatory subunit PIK3R4 and BECN1 associating with additional regulatory/auxiliary subunits to form alternative complex forms. Alternative complex forms containing a fourth regulatory subunit in a mutually exclusive manner are PI3K complex I…
Late endosome, Cytoplasmic vesicle, autophagosome, Membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 9MHF | EM | 2.73 Å | A=1-1358 |
| 9MHG | EM | 3.2 Å | A=1-1358 |
| 13BV | EM | 3.77 Å | A=1-1358 |
| 9MHH | EM | 4.5 Å | A=1-1358 |
| 9C82 | EM | 6.84 Å | A=1-1358 |
| 7BL1 | EM | 9.8 Å | CCC=1-1358 |
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