Guanine nucleotide-binding protein G(i) subunit alpha-2 (GNAI2) is a 355-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P04899.
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The mean pLDDT of this model is 94.1 (very high 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 | 88% |
| 70 to 90 | Confident: backbone generally right | 9% |
| 50 to 70 | Low: treat with caution | 3% |
| Below 50 | Very low: often disordered regions | 1% |
What pLDDT means and how to read it
Guanine nucleotide-binding proteins (G proteins) function as transducers downstream of G protein-coupled receptors (GPCRs) in numerous signaling cascades (PubMed:38505600, PubMed:29925945, PubMed:35637350, PubMed:35365641). The alpha chain contains the guanine nucleotide binding site and alternates between an active, GTP-bound state and an inactive, GDP-bound state (PubMed:12359238). Signaling by an activated GPCR promotes GDP release and GTP binding (PubMed:29925945). Examples of interacting GPCRs include the adenosine A1 receptor/ADORA1, CNR1, and FPR2 (PubMed:29925945, PubMed:35637350, PubMed:35365641). The alpha subunit has a low GTPase activity that converts bound GTP to GDP, thereby…
G proteins are composed of 3 units; alpha, beta and gamma. The alpha chain contains the guanine nucleotide binding site. In this context, forms a complex with the beta subunit GNB1 and the gamma subunit GNG2 (PubMed:28219978, PubMed:29925945, PubMed:35637350, PubMed:35365641). Interacts with GPSM1 (By similarity). Interacts with RGS12 and RGS14 (By similarity). Interacts with UNC5B; this…
Cytoplasm, Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, Cell membrane, Membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 8ZBW | EM | 2.58 Å | A=5-355 |
| 8THK | EM | 2.6 Å | A=1-57 |
| 7YK7 | EM | 2.75 Å | I=1-355 |
| 9K6L | EM | 2.77 Å | A=1-355 |
| 7WVX | EM | 2.8 Å | A=1-355 |
| 8W8A | EM | 2.8 Å | A=1-53, A=55-59 |
| 8ZSJ | EM | 2.8 Å | A=1-182 |
| 9K07 | EM | 2.83 Å | A=1-57 |
| 7RYC | EM | 2.9 Å | D=1-182 |
| 7WVV | EM | 2.9 Å | A=1-355 |
| 9DQJ | EM | 2.9 Å | B=1-57 |
| 9KFI | EM | 2.91 Å | I=1-355 |
| 9LWP | EM | 2.93 Å | A=1-57 |
| 9KFK | EM | 2.95 Å | I=1-355 |
| 8ZSV | EM | 2.96 Å | A=1-182 |
| 7WVY | EM | 3.0 Å | A=1-355 |
| 7XXI | EM | 3.0 Å | B=1-355 |
| 8W89 | EM | 3.0 Å | A=1-53, A=55-59 |
| 7YK6 | EM | 3.03 Å | I=1-355 |
| 8KGG | EM | 3.06 Å | A=1-57 |
Showing 20 of 37 experimental structures (best resolution first).
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