Collagen alpha-2(IX) chain (COL9A2) is a 689-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q14055.
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The mean pLDDT of this model is 54.5 (low 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 | 0% |
| 70 to 90 | Confident: backbone generally right | 12% |
| 50 to 70 | Low: treat with caution | 47% |
| Below 50 | Very low: often disordered regions | 41% |
What pLDDT means and how to read it
Structural component of hyaline cartilage and vitreous of the eye
Heterotrimer of an alpha 1(IX), an alpha 2(IX) and an alpha 3(IX) chain (By similarity). The chains are linked to each other by interchain disulfide bonds (By similarity). Trimers are also cross-linked via hydroxylysines (By similarity)
Secreted, extracellular space, extracellular matrix
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 5CTD | X-ray | 1.6 Å | B=517-552 |
| 5CTI | X-ray | 1.9 Å | B=517-552 |
| 5CVA | X-ray | 2.1 Å | B/E=517-552 |
| 5CVB | X-ray | 2.25 Å | B/E=517-552 |
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