Structural maintenance of chromosomes protein 3 (SMC3) is a 1217-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q9UQE7.
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The mean pLDDT of this model is 82.1 (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 | 14% |
| 70 to 90 | Confident: backbone generally right | 78% |
| 50 to 70 | Low: treat with caution | 6% |
| Below 50 | Very low: often disordered regions | 2% |
What pLDDT means and how to read it
Central component of cohesin, a complex required for chromosome cohesion during the cell cycle. The cohesin complex may form a large proteinaceous ring within which sister chromatids can be trapped. At anaphase, the complex is cleaved and dissociates from chromatin, allowing sister chromatids to segregate. Cohesion is coupled to DNA replication and is involved in DNA repair. The cohesin complex also plays an important role in spindle pole assembly during mitosis and in chromosomes movement
Forms a heterodimer with SMC1A or SMC1B in cohesin complexes (PubMed:22628566). Cohesin complexes are composed of the SMC1 (SMC1A or SMC1B) and SMC3 heterodimer attached via their SMC hinge domain, RAD21 which link them, and one STAG protein (STAG1, STAG2 or STAG3), which interacts with RAD21 (PubMed:32409525). Also found in meiosis-specific cohesin complexes (PubMed:11076961). Found in a…
Nucleus, Chromosome, Chromosome, centromere
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 8ROK | X-ray | 2.25 Å | A/C=1-961, A/C=979-1217 |
| 6WG4 | X-ray | 2.31 Å | B=493-685 |
| 8ROI | X-ray | 2.45 Å | A=1-961, A=979-1217 |
| 8ROH | X-ray | 2.6 Å | A=1-219, A=971-1217 |
| 8ROJ | X-ray | 3.0 Å | A=1-961, A=979-1217 |
| 8ROL | X-ray | 3.11 Å | A=1-961, A=979-1217 |
| 6WG6 | X-ray | 3.54 Å | B/D/F/H/J/L=466-713 |
| 8P0A | EM | 3.67 Å | B=1-961, B=979-1217 |
| 6WGE | EM | 3.9 Å | B=1-1217 |
| 8PQ5 | EM | 4.4 Å | B=799-1217 |
| 6WG3 | EM | 5.3 Å | B=1-1217 |
| 7W1M | EM | 6.5 Å | B=1-1217 |
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