Beta-2-microglobulin (B2m) is a 119-residue protein from Mus musculus. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P01887.
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The mean pLDDT of this model is 93.8 (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 | 82% |
| 70 to 90 | Confident: backbone generally right | 11% |
| 50 to 70 | Low: treat with caution | 7% |
| Below 50 | Very low: often disordered regions | 0% |
What pLDDT means and how to read it
Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system
Heterodimer of an alpha chain and a beta chain. Beta-2-microglobulin is the beta-chain of major histocompatibility complex class I molecules. Forms a heterotrimer with MR1 and a metabolite antigen
Secreted
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 1LK2 | X-ray | 1.35 Å | B=21-119 |
| 1G7P | X-ray | 1.5 Å | B=21-119 |
| 1KPU | X-ray | 1.5 Å | B=21-119 |
| 5WEU | X-ray | 1.58 Å | B=21-119 |
| 1G7Q | X-ray | 1.6 Å | B=21-119 |
| 3G08 | X-ray | 1.6 Å | B=21-119 |
| 3GMO | X-ray | 1.6 Å | B=21-119 |
| 7LFK | X-ray | 1.6 Å | B/E=21-119 |
| 7LFL | X-ray | 1.6 Å | B=21-119 |
| 7LFM | X-ray | 1.6 Å | B/E=21-119 |
| 6C6F | X-ray | 1.67 Å | B=21-119 |
| 1FZK | X-ray | 1.7 Å | B=21-119 |
| 3ECB | X-ray | 1.7 Å | B=21-119 |
| 3GML | X-ray | 1.7 Å | B=21-119 |
| 3GMN | X-ray | 1.7 Å | B=21-119 |
| 3GMP | X-ray | 1.7 Å | B=21-119 |
| 3T1F | X-ray | 1.7 Å | B=21-119 |
| 7LFI | X-ray | 1.7 Å | B/E=21-119 |
| 7LFJ | X-ray | 1.7 Å | B/E=21-119 |
| 1KPV | X-ray | 1.71 Å | B=21-119 |
Showing 20 of 324 experimental structures (best resolution first).
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