Guanine nucleotide-binding protein G(s) subunit alpha isoforms XLas (GNAS) is a 1037-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q5JWF2.
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The mean pLDDT of this model is 56.7 (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 | 27% |
| 70 to 90 | Confident: backbone generally right | 9% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 62% |
What pLDDT means and how to read it
Guanine nucleotide-binding proteins (G proteins) function as transducers in numerous signaling pathways controlled by G protein-coupled receptors (GPCRs). The alpha chain contains the guanine nucleotide binding site and alternates between an active, GTP-bound state and an inactive, GDP-bound state. Signaling by an activated GPCR promotes GDP release and GTP binding. The alpha subunit has a low GTPase activity that converts bound GTP to GDP, thereby terminating the signal. Both GDP release and GTP hydrolysis are modulated by numerous regulatory proteins. Signaling involves the activation of adenylyl cyclases, resulting in increased levels of the signaling molecule cAMP. GNAS functions…
G proteins are composed of 3 units; alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site. Interacts through its N-terminal region with ALEX which is produced from the same locus in a different open reading frame. This interaction may inhibit its adenylyl cyclase-stimulating activity (By similarity). Interacts with MAGED2 (PubMed:27120771). Interacts with FSHR…
Cell membrane, Apical cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 9BKK | EM | 2.51 Å | A=847-1037 |
| 8WW2 | EM | 2.79 Å | A=683-1037 |
| 8I2G | EM | 2.8 Å | A=848-1037 |
| 9DQJ | EM | 2.9 Å | B=847-989, B=991-1000, B=1002-1029, B=1032-1037 |
| 9J1P | EM | 2.99 Å | A=848-894, A=909-1037 |
| 8ZH8 | EM | 3.19 Å | A=848-989, A=991-1000, A=1002-1029, A=1032-1037 |
| 8JHI | EM | 3.2 Å | A=655-707, A=847-1037 |
| 8GY7 | EM | 3.3 Å | A=671-675, A=677-710, A=848-894, A=909-1037 |
| 8JHB | EM | 3.3 Å | A=655-707, A=847-896, A=907-1037 |
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