Properdin (CFP) is a 469-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P27918.
Explore in 3D Color by confidence AlphaFold DB UniProt
The mean pLDDT of this model is 83.3 (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 | 54% |
| 70 to 90 | Confident: backbone generally right | 23% |
| 50 to 70 | Low: treat with caution | 18% |
| Below 50 | Very low: often disordered regions | 5% |
What pLDDT means and how to read it
A positive regulator of the alternate pathway (AP) of complement (PubMed:16301317, PubMed:20382442, PubMed:28264884, PubMed:9748277). It binds to and stabilizes the C3- and C5-convertase enzyme complexes (PubMed:16301317, PubMed:20382442, PubMed:28264884, PubMed:9748277). Inhibits CFI-CFH mediated degradation of Complement C3 beta chain (C3b) (PubMed:31507604)
In plasma, properdin exists as dimers, trimers or tetramers in the relative proportions of 26:54:20 (PubMed:15491616, PubMed:20382442, PubMed:28264884, PubMed:31507604). Interacts with the pro-C3-convertase enzyme complex (C3b-Bb) comprised of Complement C3 beta chain (C3b) and the Complement factor B Bb fragment (Bb), where it binds (via its TSP type-1 5 domain) with C3b and Bb…
Secreted
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 8Q6R | X-ray | 1.9 Å | C/E=28-135, D/F=256-469 |
| 6S08 | X-ray | 2.03 Å | A=256-469, B=26-132 |
| 6S0B | X-ray | 2.31 Å | A=256-469, B=26-132 |
| 6S0A | X-ray | 2.52 Å | A=256-469, B=26-191 |
| 9U62 | EM | 2.7 Å | P=1-453 |
| 6RUS | X-ray | 2.8 Å | A=28-255, B=256-469 |
| 7B26 | X-ray | 3.4 Å | A=1-134, B=256-469 |
| 6SEJ | X-ray | 3.5 Å | A=28-191, B=256-469 |
| 6RV6 | X-ray | 3.51 Å | A=28-191, B=256-469 |
| 7NOZ | X-ray | 3.9 Å | C=28-190, D=255-461 |
| 6RUR | X-ray | 6.0 Å | A=28-255, B=256-469 |
| 6RUV | X-ray | 6.15 Å | U/X=28-191, V/Y=256-469 |
| 1W0R | X-ray | A/B=28-469 | |
| 1W0S | X-ray | A/B/C=28-469 |
MolViewer loads the AlphaFold model straight from AlphaFold DB into your browser. Show it as a cartoon, color by pLDDT, measure distances and angles, and load a PDB structure next to it to compare.