Cholera enterotoxin subunit B (ctxB) is a 124-residue protein from Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P01556.
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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 | 69% |
| 70 to 90 | Confident: backbone generally right | 14% |
| 50 to 70 | Low: treat with caution | 3% |
| Below 50 | Very low: often disordered regions | 14% |
What pLDDT means and how to read it
The B subunit pentameric ring directs the A subunit to its target by binding to the GM1 gangliosides present on the surface of the intestinal epithelial cells. It can bind five GM1 gangliosides. It has no toxic activity by itself
The holotoxin (choleragen) consists of a pentameric ring of B subunits whose central pore is occupied by the A subunit. The A subunit contains two chains, A1 and A2, linked by a disulfide bridge
Secreted, Host cell membrane
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 5LZG | X-ray | 1.13 Å | A/B/C/D/E=22-124 |
| 5LZJ | X-ray | 1.2 Å | A/B/C/D/E=22-124 |
| 3CHB | X-ray | 1.25 Å | D/E/F/G/H=22-124 |
| 1JR0 | X-ray | 1.3 Å | D/E/F/G/H=22-124 |
| 1RDP | X-ray | 1.35 Å | D/E/F/G/H=22-124 |
| 1RF2 | X-ray | 1.35 Å | D/E/F/G/H=22-124 |
| 1RD9 | X-ray | 1.44 Å | D/E/F/G/H=22-124 |
| 1MD2 | X-ray | 1.45 Å | D/E/F/G/H=22-124 |
| 5ELC | X-ray | 1.5 Å | A/B/C/D/E/F/G/H/I/J=22-124 |
| 6HJD | X-ray | 1.54 Å | A/B/C/D/E/F/G/H/I/J=22-124 |
| 5ELF | X-ray | 1.55 Å | A/B/C/D/E/F/G/H/I/J=22-124 |
| 1RCV | X-ray | 1.6 Å | D/E/F/G/H=22-124 |
| 5ELE | X-ray | 1.6 Å | A/B/C/D/E/F/G/H/I/J=22-124 |
| 6HMY | X-ray | 1.6 Å | A/B/C/D/E/F/G/H/I/J=22-124 |
| 8OXS | X-ray | 1.6 Å | C/D/E/F/G/H/I/J/K/L=22-124 |
| 8Q6I | X-ray | 1.6 Å | D/E/F/G/H=22-124 |
| 1S5D | X-ray | 1.75 Å | D/E/F/G/H=22-124 |
| 1S5E | X-ray | 1.9 Å | D/E/F/G/H/J/K/L/M/N=22-124 |
| 3EFX | X-ray | 1.94 Å | D/E/F/G/H/I/J/K/L/M=52-67, D/E/F/G/H/I/J/K/L/M=96-114 |
| 6HMW | X-ray | 1.95 Å | A/B/C/D/E/F/G/H/I/J=22-124 |
Showing 20 of 34 experimental structures (best resolution first).
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