T cell receptor alpha chain constant (TRAC) is a 140-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P01848.
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The mean pLDDT of this model is 92.0 (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 | 78% |
| 70 to 90 | Confident: backbone generally right | 20% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 0% |
What pLDDT means and how to read it
Constant region of T cell receptor (TR) alpha chain (PubMed:24600447). Alpha-beta T cell receptors are antigen specific receptors which are essential to the immune response and are present on the cell surface of T lymphocytes. Recognize peptide-major histocompatibility (MH) (pMH) complexes that are displayed by antigen presenting cells (APC), a prerequisite for efficient T cell adaptive immunity against pathogens (PubMed:25493333). Binding of alpha-beta TR to pMH complex initiates TR-CD3 clustering on the cell surface and intracellular activation of LCK that phosphorylates the ITAM motifs of CD3G, CD3D, CD3E and CD247 enabling the recruitment of ZAP70. In turn, ZAP70 phosphorylates LAT,…
Alpha-beta TR is a heterodimer composed of an alpha and beta chain; disulfide-linked. The alpha-beta TR is associated with the transmembrane signaling CD3 coreceptor proteins to form the TR-CD3 (TcR or TCR). The assembly of alpha-beta TR heterodimers with CD3 occurs in the endoplasmic reticulum where a single alpha-beta TR heterodimer associates with one CD3D-CD3E heterodimer, one CD3G-CD3E…
Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 4UDT | X-ray | 1.35 Å | A=1-93 |
| 4WW1 | X-ray | 1.38 Å | A=1-93 |
| 1OGA | X-ray | 1.4 Å | D=1-92 |
| 2BNU | X-ray | 1.4 Å | A=1-89 |
| 1KGC | X-ray | 1.5 Å | D=1-93 |
| 2BNQ | X-ray | 1.7 Å | D=1-89 |
| 2P5E | X-ray | 1.89 Å | D=1-79 |
| 2BNR | X-ray | 1.9 Å | D=1-89 |
| 2IAL | X-ray | 1.92 Å | A/C=1-93 |
| 5C0C | X-ray | 1.97 Å | D/I=1-89 |
| 2VLM | X-ray | 1.98 Å | D=1-89 |
| 5KSA | X-ray | 2.0 Å | C=1-93 |
| 7RYL | X-ray | 2.0 Å | D=1-93 |
| 5EU6 | X-ray | 2.02 Å | D=1-87 |
| 5C0B | X-ray | 2.03 Å | D/I=1-89 |
| 9ZZV | X-ray | 2.05 Å | A=1-94 |
| 3QEU | X-ray | 2.09 Å | A/D=1-91 |
| 2F53 | X-ray | 2.1 Å | D=1-77 |
| 2XNA | X-ray | 2.1 Å | A=1-93 |
| 4G8F | X-ray | 2.1 Å | A=1-93 |
Showing 20 of 158 experimental structures (best resolution first).
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