Small ribosomal subunit protein uS9 (rpsI) is a 130-residue protein from Escherichia coli (strain K12). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P0A7X3.
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The mean pLDDT of this model is 92.8 (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 | 89% |
| 70 to 90 | Confident: backbone generally right | 9% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 1% |
What pLDDT means and how to read it
The C-terminal tail plays a role in the affinity of the 30S P site for different tRNAs. Mutations that decrease this affinity are suppressed in the 70S ribosome
Part of the 30S ribosomal subunit (PubMed:10094780, PubMed:1091515, PubMed:12244297, PubMed:12809609, PubMed:16272117, PubMed:27906160, PubMed:27906161, PubMed:27934701, PubMed:28077875, PubMed:7556101). Contacts 16S rRNA (PubMed:7556101). Cross-links to the P site tRNA and weakly to the A site tRNA (PubMed:15308780, PubMed:8524654)
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 8B0X | EM | 1.55 Å | I=1-130 |
| 9Q87 | EM | 1.55 Å | I=1-130 |
| 8CF1 | EM | 1.82 Å | I=1-130 |
| 8FTO | EM | 1.85 Å | I=1-130 |
| 9GHE | EM | 1.87 Å | I=1-130 |
| 8CGI | EM | 1.89 Å | I=1-130 |
| 8AYE | EM | 1.96 Å | I=1-130 |
| 7K00 | EM | 1.98 Å | I=1-130 |
| 8QOA | EM | 2.0 Å | I=1-130 |
| 8G6W | EM | 2.02 Å | I=1-130 |
| 8BIL | EM | 2.04 Å | m=1-130 |
| 8BIM | EM | 2.04 Å | m=1-130 |
| 8CA7 | EM | 2.06 Å | I=1-130 |
| 4YBB | X-ray | 2.1 Å | AI/BI=4-130 |
| 8EMM | EM | 2.1 Å | I=1-130 |
| 8BGE | EM | 2.11 Å | m=1-130 |
| 8CAZ | EM | 2.11 Å | I=1-130 |
| 9SLG | EM | 2.16 Å | I=1-130 |
| 8CF8 | EM | 2.2 Å | I=1-130 |
| 8QBT | EM | 2.2 Å | q=1-130 |
Showing 20 of 526 experimental structures (best resolution first).
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