C3a anaphylatoxin chemotactic receptor (C3AR1) is a 482-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q16581.
Explore in 3D Color by confidence AlphaFold DB UniProt
The mean pLDDT of this model is 68.8 (low 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 | 37% |
| 70 to 90 | Confident: backbone generally right | 21% |
| 50 to 70 | Low: treat with caution | 5% |
| Below 50 | Very low: often disordered regions | 37% |
What pLDDT means and how to read it
Receptor for the chemotactic and inflammatory peptide anaphylatoxin C3a, stimulating chemotaxis, granule enzyme release and superoxide anion production (PubMed:12871936, PubMed:37852260, PubMed:8702752). Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors, such as adenylate cyclase (PubMed:37852260). C3AR1 is coupled to G(i)/G(o) (GNAI1 or GNAO1) G alpha proteins and mediates inhibition of adenylate cyclase (PubMed:37852260)
Interacts with VGF-derived peptide TLQP-21 (By similarity). Interacts (when phosphorylated) with ARRB1; the interaction is associated with internalization of the receptor and short-term desensitization to the ligand (PubMed:38175886)
Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 9IPV | EM | 2.53 Å | R=1-482 |
| 9KVP | EM | 2.79 Å | C=2-482 |
| 8IA8 | EM | 2.86 Å | A=1-482 |
| 8ZWG | EM | 2.87 Å | A=1-482 |
| 8I95 | EM | 2.88 Å | C=2-482 |
| 8HK2 | EM | 2.9 Å | A=1-476 |
| 8ZWF | EM | 3.0 Å | A=1-362, A=373-482 |
| 8J6D | EM | 3.1 Å | C=2-482 |
| 8I9L | EM | 3.18 Å | C=2-482 |
| 8I97 | EM | 3.19 Å | C=2-482 |
| 8HK3 | EM | 3.2 Å | C=1-476 |
| 8I9S | EM | 3.26 Å | C=2-482 |
| 9KUT | EM | 3.29 Å | C=2-482 |
| 9KZ2 | EM | 3.43 Å | C=2-482 |
| 9IPY | EM | 3.5 Å | R=2-367, R=370-482 |
| 9ISI | EM | 3.56 Å | B=2-365, B=370-482 |
| 8I9A | EM | 3.57 Å | C=2-482 |
| 8JA3 | EM | 3.94 Å | U/V=459-468 |
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.