Small ribosomal subunit protein bS1 (rpsA) is a 557-residue protein from Escherichia coli (strain K12). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P0AG67.
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The mean pLDDT of this model is 69.9 (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 | 52% |
| 50 to 70 | Low: treat with caution | 46% |
| Below 50 | Very low: often disordered regions | 2% |
What pLDDT means and how to read it
Required for translation of most natural mRNAs except for leaderless mRNA (PubMed:12068815, PubMed:17376482, PubMed:24339747, PubMed:7003157, PubMed:9677288). Binds mRNA upstream of the Shine-Dalgarno (SD) sequence and helps it bind to the 30S ribosomal subunit; acts as an RNA chaperone to unfold structured mRNA on the ribosome but is not essential for mRNAs with strong SDs and little 5'-UTR structure, thus it may help fine-tune which mRNAs that are translated (PubMed:24339747). Unwinds dsRNA by binding to transiently formed ssRNA regions; binds about 10 nucleotides (PubMed:22908248). Has a preference for polypyrimidine tracts (PubMed:778845). Negatively autoregulates its own translation…
Part of the 30S ribosomal subunit; the largest protein subunit, it is loosely associated and not always found in ribosomal crystal structures (PubMed:342903, PubMed:7003157, PubMed:7041110, PubMed:778845, PubMed:35264790). Does not bind rRNA. Probably requires ribosomal protein uS2 to associate with the 30S subunit (PubMed:12068815). Binds in the junction of the head, platform and main body of…
Cytoplasm
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 2BH8 | X-ray | 1.9 Å | A/B=362-401 |
| 9GUU | EM | 2.5 Å | B=1-557 |
| 9IOT | EM | 2.7 Å | 8=1-557 |
| 9GUP | EM | 2.8 Å | B=1-557 |
| 9GUT | EM | 2.8 Å | B=1-557 |
| 4Q7J | X-ray | 2.9 Å | D/H=1-273 |
| 6H4N | EM | 3.0 Å | y=1-557 |
| 9GUV | EM | 3.0 Å | B=1-557 |
| 6X7K | EM | 3.1 Å | H=1-557 |
| 8URY | EM | 3.1 Å | H=1-557 |
| 9GUQ | EM | 3.1 Å | B=1-557 |
| 9GUW | EM | 3.1 Å | B=1-557 |
| 6X6T | EM | 3.2 Å | H=1-557 |
| 8UQL | EM | 3.2 Å | H=1-557 |
| 4R71 | X-ray | 3.21 Å | E/F=2-171 |
| 8R3V | EM | 3.28 Å | Z1=1-557 |
| 8PEG | EM | 3.3 Å | Z=1-557 |
| 9GUX | EM | 3.3 Å | B=1-557 |
| 6ZTJ | EM | 3.4 Å | AY=1-557 |
| 8UR0 | EM | 3.4 Å | H=1-557 |
Showing 20 of 69 experimental structures (best resolution first).
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