COMPASS component SPP1 (SPP1) is a 353-residue protein from Saccharomyces cerevisiae (strain ATCC 204508 / S288c). This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q03012.
Explore in 3D Color by confidence AlphaFold DB UniProt
The mean pLDDT of this model is 87.6 (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 | 70% |
| 70 to 90 | Confident: backbone generally right | 22% |
| 50 to 70 | Low: treat with caution | 1% |
| Below 50 | Very low: often disordered regions | 7% |
What pLDDT means and how to read it
Component of the Set1C/COMPASS complex that specifically mono-, di- and trimethylates histone H3 to form H3K4me1/2/3, which subsequently plays a role in telomere length maintenance and transcription elongation regulation (PubMed:11742990, PubMed:11752412, PubMed:11805083). COMPASS recognizes ubiquitinated H2B on one face of the nucleosome which stimulates the methylation of H3 on the opposing face (PubMed:31922488). SPP1/CPS40 can recognize methylated histone lysine residue H3K4me3 or unmethylated H3K4 (PubMed:30100186, PubMed:31253666). Stimulates the RNA binding activity of SET1 (PubMed:29071121)
Component of the Set1C/COMPASS complex which consists of SET1(2), BRE2(2), SPP1(2), SDC1(1), SHG1(1), SWD1(1), SWD2(1), and SWD3(1)
Nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 6J2P | X-ray | 2.85 Å | A/B/C/D=1-124 |
| 6VEN | EM | 3.37 Å | R=2-353 |
| 6BX3 | EM | 4.3 Å | F=117-353 |
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.