Beta-2-microglobulin (B2M) is a 119-residue protein from Pongo pygmaeus. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P16213.
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The mean pLDDT of this model is 94.2 (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 | 83% |
| 70 to 90 | Confident: backbone generally right | 12% |
| 50 to 70 | Low: treat with caution | 5% |
| 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 (By similarity)
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 |
|---|---|---|---|
| 7SR5 | X-ray | 2.35 Å | A/C=21-119 |
| 7SRK | X-ray | 2.5 Å | A/C=22-119 |
| 7STG | X-ray | 2.7 Å | A/C/E/G/I/K/M/O/Q/S/U/W/Y/a/c/e=21-119 |
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