Histamine H2 receptor (HRH2) is a 359-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P25021.
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The mean pLDDT of this model is 82.9 (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 | 13% |
| 50 to 70 | Low: treat with caution | 8% |
| Below 50 | Very low: often disordered regions | 14% |
What pLDDT means and how to read it
G protein-coupled receptor for histamine, primarily mediating gastric acid secretion. Predominantly expressed in the gastric mucosa, couples to G(s) G alpha proteins upon histamine binding, leading to activation of adenylate cyclase and increased intracellular cyclic AMP (cAMP) levels (PubMed:38647423, PubMed:39333117). This signaling cascade stimulates parietal cells to secrete hydrochloric acid, playing a key role in digestive physiology. Also expressed in other tissues, including the heart and central nervous system, where it may contribute to cardiac stimulation and modulate neurotransmitter release (By similarity)
Interacts with GNAS
Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 8YN3 | EM | 2.56 Å | R=1-312 |
| 8YUT | EM | 2.7 Å | R=2-359 |
| 9IXJ | EM | 2.92 Å | R=1-359 |
| 8YN4 | EM | 2.97 Å | R=1-312 |
| 7UL3 | EM | 3.0 Å | A=1-199, A=245-359 |
| 8POK | EM | 3.4 Å | A=1-359 |
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