S-adenosylmethionine synthase (metK) is a 384-residue protein from Escherichia coli (strain K12). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P0A817.
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The mean pLDDT of this model is 96.1 (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 | 92% |
| 70 to 90 | Confident: backbone generally right | 8% |
| 50 to 70 | Low: treat with caution | 1% |
| Below 50 | Very low: often disordered regions | 0% |
What pLDDT means and how to read it
Catalyzes the formation of S-adenosylmethionine (AdoMet) from methionine and ATP. The overall synthetic reaction is composed of two sequential steps, AdoMet formation and the subsequent tripolyphosphate hydrolysis which occurs prior to release of AdoMet from the enzyme (PubMed:10551856, PubMed:10660564, PubMed:6251075, PubMed:7629147, PubMed:7629176, PubMed:9753435). Is essential for growth (PubMed:11952912)
Homotetramer; dimer of dimers (PubMed:10660564, PubMed:14967023, PubMed:6251075, PubMed:7629147, PubMed:7629176, PubMed:8550549, PubMed:8611562, PubMed:8723769). The active sites are at the interface between subunits; each dimer has two active sites (PubMed:14967023, PubMed:8550549, PubMed:8611562, PubMed:8723769)
Cytoplasm
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 7R2W | X-ray | 1.6 Å | A=1-384 |
| 1P7L | X-ray | 2.5 Å | A/B/C/D=2-384 |
| 1RG9 | X-ray | 2.5 Å | A/B/C/D=2-384 |
| 1MXA | X-ray | 2.8 Å | A=2-384 |
| 1MXB | X-ray | 2.8 Å | A=2-384 |
| 8BB1 | EM | 2.8 Å | A/B/C/D=1-384 |
| 1MXC | X-ray | 3.0 Å | A=2-384 |
| 1XRA | X-ray | 3.0 Å | A=2-384 |
| 1XRB | X-ray | 3.0 Å | A=2-384 |
| 1XRC | X-ray | 3.0 Å | A=2-384 |
| 8P4O | EM | 3.04 Å | 1=1-384 |
| 1FUG | X-ray | 3.2 Å | A/B=2-384 |
| 7OCK | EM | 3.6 Å | B/C/D/E/F/G/H/I=1-384 |
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