B-cell receptor CD22 (CD22) is a 847-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P20273.
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The mean pLDDT of this model is 79.4 (confident 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 | 51% |
| 70 to 90 | Confident: backbone generally right | 27% |
| 50 to 70 | Low: treat with caution | 4% |
| Below 50 | Very low: often disordered regions | 18% |
What pLDDT means and how to read it
Most highly expressed siglec (sialic acid-binding immunoglobulin-like lectin) on B-cells that plays a role in various aspects of B-cell biology including differentiation, antigen presentation, and trafficking to bone marrow (PubMed:34330755, PubMed:8627166). Binds to alpha 2,6-linked sialic acid residues of surface molecules such as CD22 itself, CD45 and IgM in a cis configuration. Can also bind to ligands on other cells as an adhesion molecule in a trans configuration (PubMed:20172905). Acts as an inhibitory coreceptor on the surface of B-cells and inhibits B-cell receptor induced signaling, characterized by inhibition of the calcium mobilization and cellular activation. Mechanistically,…
Predominantly monomer of isoform CD22-beta. Also found as heterodimer of isoform CD22-beta and a shorter isoform. Interacts with PTPN6/SHP-1, LYN, SYK, PIK3R1/PIK3R2 and PLCG1 upon phosphorylation. Interacts with GRB2, INPP5D and SHC1 upon phosphorylation (By similarity). May form a complex with INPP5D/SHIP, GRB2 and SHC1
Cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 5VKJ | X-ray | 2.12 Å | A=20-330 |
| 5VKM | X-ray | 2.2 Å | A=20-330 |
| 7O52 | X-ray | 2.41 Å | U=504-687 |
| 9ROB | X-ray | 2.7 Å | A/B=20-330 |
| 9RM3 | X-ray | 2.86 Å | A/B/C/D=20-330 |
| 5VL3 | X-ray | 3.1 Å | Q/R/S/T=22-330 |
| 9RO7 | X-ray | 3.15 Å | A/B/C/D=20-330 |
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