DNA-directed RNA polymerase I subunit RPA2 (POLR1B) is a 1135-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q9H9Y6.
Explore in 3D Color by confidence AlphaFold DB UniProt
The mean pLDDT of this model is 92.2 (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 | 79% |
| 70 to 90 | Confident: backbone generally right | 19% |
| 50 to 70 | Low: treat with caution | 2% |
| Below 50 | Very low: often disordered regions | 0% |
What pLDDT means and how to read it
Catalytic core component of RNA polymerase I (Pol I), a DNA-dependent RNA polymerase which synthesizes ribosomal RNA precursors using the four ribonucleoside triphosphates as substrates. Transcribes 47S pre-rRNAs from multicopy rRNA gene clusters, giving rise to 5.8S, 18S and 28S ribosomal RNAs (PubMed:11250903, PubMed:11283244, PubMed:16858408, PubMed:34671025, PubMed:34887565, PubMed:36271492). Pol I-mediated transcription cycle proceeds through transcription initiation, transcription elongation and transcription termination stages. During transcription initiation, Pol I pre-initiation complex (PIC) is recruited by the selectivity factor 1 (SL1/TIF-IB) complex bound to the core promoter…
Component of the RNA polymerase I (Pol I) complex consisting of 13 subunits: a ten-subunit catalytic core composed of POLR1A/RPA1, POLR1B/RPA2, POLR1C/RPAC1, POLR1D/RPAC2, POLR1H/RPA12, POLR2E/RPABC1, POLR2F/RPABC2, POLR2H/RPABC3, POLR2K/RPABC4 and POLR2L/RPABC5; a mobile stalk subunit POLR1F/RPA43 protruding from the core and additional subunits homologous to general transcription factors…
Nucleus, nucleolus, Chromosome
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 7OB9 | EM | 2.7 Å | B=1-1135 |
| 7VBB | EM | 2.81 Å | B=1-1135 |
| 7VBA | EM | 2.89 Å | B=1-1135 |
| 7VBC | EM | 3.01 Å | B=1-1135 |
| 7OBA | EM | 3.1 Å | B=1-1135 |
| 7OBB | EM | 3.3 Å | B=1-1135 |
| 8A43 | EM | 4.09 Å | B=1-1135 |
MolViewer loads the AlphaFold model straight from AlphaFold DB into your browser. Show it as a cartoon, color by pLDDT, measure distances and angles, and load a PDB structure next to it to compare.