Peptide chain release factor RF2 (prfB) is a 365-residue protein from Escherichia coli (strain K12). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P07012.
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The mean pLDDT of this model is 85.9 (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 | 48% |
| 70 to 90 | Confident: backbone generally right | 43% |
| 50 to 70 | Low: treat with caution | 9% |
| Below 50 | Very low: often disordered regions | 0% |
What pLDDT means and how to read it
Peptide chain release factor 2 directs the termination of translation in response to the peptide chain termination codons UGA and UAA (PubMed:11118225, PubMed:17932046). Acts as a peptidyl-tRNA hydrolase (PubMed:22857598, PubMed:27934701). In the presence of truncated mRNA in the 70S ribosome, ArfA and RF2 interact such that the GGQ peptide hydrolysis motif of RF2 rises into the peptidyl-transferase center (PTC) and releases the ribosome (PubMed:27906160, PubMed:27906161, PubMed:27934701, PubMed:28077875). Recruited by ArfA to rescue stalled ribosomes in the absence of a normal stop codon (PubMed:22857598, PubMed:22922063, PubMed:25355516). A TnaC-stalled ribosome binds RF2, but the active…
Interacts with the ribosome (PubMed:12511960, PubMed:12511961, PubMed:22857598, PubMed:22922063, PubMed:25355516). Recruited to stalled ribosomes by ArfA, in the presence of truncated mRNA, ArfA influences RF2 conformation so RF2 can hydrolyze the peptidyl-tRNA bond (PubMed:27906160, PubMed:27906161, PubMed:27934701, PubMed:28077875). Biotinylated tnaC mRNA can be detected in a stalled 70S…
Cytoplasm
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 1GQE | X-ray | 1.81 Å | A=1-365 |
| 7O1C | EM | 2.6 Å | B9=1-365 |
| 8P16 | EM | 2.77 Å | 6=1-365 |
| 8P18 | EM | 2.77 Å | 6=1-365 |
| 8QK7 | EM | 2.77 Å | 6=1-365 |
| 8P17 | EM | 2.78 Å | 6=1-365 |
| 8ZTV | EM | 2.9 Å | V=1-365 |
| 5MDV | EM | 2.97 Å | 7=1-365 |
| 5H5U | EM | 3.0 Å | 4=1-365 |
| 5MDW | EM | 3.06 Å | 7=1-365 |
| 5DFE | X-ray | 3.1 Å | QY/XY=1-365 |
| 5MGP | EM | 3.1 Å | z=6-364 |
| 6C4H | EM | 3.1 Å | v=1-365 |
| 5U9F | EM | 3.2 Å | Z=1-365 |
| 5U9G | EM | 3.2 Å | Z=1-365 |
| 6C4I | EM | 3.24 Å | v=1-365 |
| 5CZP | X-ray | 3.3 Å | QY/XY=1-365 |
| 6OG7 | EM | 3.3 Å | 8=1-365 |
| 5U4I | EM | 3.5 Å | v=1-365 |
| 7OJ0 | EM | 3.5 Å | 8=1-365 |
Showing 20 of 28 experimental structures (best resolution first).
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