Small ubiquitin-related modifier 3 (SUMO3) is a 103-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P55854.
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The mean pLDDT of this model is 81.1 (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 | 53% |
| 70 to 90 | Confident: backbone generally right | 19% |
| 50 to 70 | Low: treat with caution | 19% |
| Below 50 | Very low: often disordered regions | 8% |
What pLDDT means and how to read it
Ubiquitin-like protein which can be covalently attached to target lysines either as a monomer or as a lysine-linked polymer. Does not seem to be involved in protein degradation and may function as an antagonist of ubiquitin in the degradation process. Plays a role in a number of cellular processes such as nuclear transport, DNA replication and repair, mitosis and signal transduction. Covalent attachment to its substrates requires prior activation by the E1 complex SAE1-SAE2 and linkage to the E2 enzyme UBE2I, and can be promoted by an E3 ligase such as PIAS1-4, RANBP2 or CBX4 (PubMed:11451954, PubMed:18538659, PubMed:21965678). Plays a role in the regulation of sumoylation status of SETX…
Covalently attached to a number of proteins. Interacts with BMAL1 (By similarity). Interacts with USP25 (via ts SIM domain); the interaction sumoylates USP25 and inhibits its ubiquitin hydrolyzing activity. Interacts with SAE2 and UBE2I
Cytoplasm, Nucleus, Nucleus, PML body
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 7R2E | X-ray | 1.74 Å | C/D=16-91 |
| 7ZJU | X-ray | 2.17 Å | B/D=2-91 |
| 9GNN | X-ray | 2.36 Å | C/D=14-91 |
| 2IO1 | X-ray | 2.6 Å | B/D/F=14-103 |
| 6NNQ | X-ray | 2.62 Å | B=15-92 |
| 1U4A | NMR | A=14-92 | |
| 2MP2 | NMR | A=12-92, B=2-90 | |
| 6K5R | NMR | A=15-91 |
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