Colicin E3 immunity protein (imm) is a 85-residue protein from Escherichia coli. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P02984.
Explore in 3D Color by confidence AlphaFold DB UniProt
The mean pLDDT of this model is 95.0 (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 | 93% |
| 70 to 90 | Confident: backbone generally right | 4% |
| 50 to 70 | Low: treat with caution | 4% |
| Below 50 | Very low: often disordered regions | 0% |
What pLDDT means and how to read it
The cognate immunity protein for colicin E3 (ColE3), protects cells which harbor the plasmid ColE3 against the toxic action of ColE3 (PubMed:10986462, PubMed:11741540, PubMed:336615, PubMed:6295812). This protein inhibits the 16S RNA hydrolyzing activity of ColE3 by binding with very high affinity to the C-terminal catalytic domain of ColE3 (PubMed:10986462, PubMed:11741540)
Native colicin E3 is a 1:1 complex of A chain and protein B (Im3) (PubMed:10986462, PubMed:11741540, PubMed:336615). Binds between the translocation and cytotoxic RNase domains of intact ColE3, blocking access to the 16S rRNA substrate (PubMed:11741540). Forms a very tight 1:1 complex with the cytotoxic fragment (residues 456-551) of ColE3 (ceaC) (PubMed:10986462, PubMed:11741540)
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 3EIP | X-ray | 1.8 Å | A/B=2-85 |
| 2B5U | X-ray | 2.3 Å | B/D=2-85 |
| 1E44 | X-ray | 2.4 Å | A=1-85 |
| 4UDM | X-ray | 2.96 Å | A=1-85 |
| 1JCH | X-ray | 3.02 Å | B/D=2-85 |
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.