Histamine H4 receptor (HRH4) is a 390-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q9H3N8.
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The mean pLDDT of this model is 76.3 (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 | 40% |
| 70 to 90 | Confident: backbone generally right | 33% |
| 50 to 70 | Low: treat with caution | 8% |
| Below 50 | Very low: often disordered regions | 20% |
What pLDDT means and how to read it
G protein-coupled receptor primarily expressed in immune cells such as mast cells, eosinophils, basophils, dendritic cells and neutrophils that plays a key role in immune and inflammatory responses (PubMed:26948974). Mediates chemotaxis of immune cells to sites of inflammation or injury by responding to histamine (PubMed:26948974). Activation by histamine also influences the release of proinflammatory cytokines such as TNF, CCL4, IL6 and IFN-gamma (PubMed:29600327, PubMed:31583075). Ligand binding induces a conformation change that triggers signaling via G(i)/GNAI1 leading to decreased intracellular cAMP levels by inhibiting adenylate cyclase activity (PubMed:39333117). In addition, plays…
Interacts with TSPAN4. Interacts with GNAI1 (PubMed:39333117)
Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 8YN9 | EM | 2.3 Å | R=1-382 |
| 9JED | EM | 2.58 Å | R=1-390 |
| 8YNA | EM | 2.63 Å | R=1-382 |
| 9LRC | EM | 2.84 Å | R=2-390 |
| 9LRE | EM | 2.84 Å | R=2-390 |
| 9L42 | EM | 2.9 Å | A=1-380 |
| 7YFC | EM | 3.0 Å | R=1-390 |
| 8HN8 | EM | 3.0 Å | R=4-390 |
| 8HOC | EM | 3.0 Å | R=4-390 |
| 8JXW | EM | 3.01 Å | R=1-390 |
| 8JXX | EM | 3.06 Å | R=1-390 |
| 8JXT | EM | 3.07 Å | R=1-390 |
| 7YFD | EM | 3.1 Å | R=1-390 |
| 8JXV | EM | 3.21 Å | R=1-390 |
| 9JG1 | EM | 3.62 Å | R=1-207, R=289-368 |
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