Histone H3-like centromeric protein cid (cid) is a 225-residue protein from Drosophila melanogaster. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: Q9V6Q2.
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The mean pLDDT of this model is 68.6 (low 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 | 36% |
| 70 to 90 | Confident: backbone generally right | 8% |
| 50 to 70 | Low: treat with caution | 24% |
| Below 50 | Very low: often disordered regions | 31% |
What pLDDT means and how to read it
Histone H3-like variant which exclusively replaces conventional H3 in the nucleosome core of centromeric chromatin at the inner plate of the kinetochore (PubMed:11483958, PubMed:16839185). Required for recruitment and assembly of kinetochore proteins, mitotic progression and chromosome segregation (PubMed:11483958, PubMed:16839185, PubMed:24703848). May serve as an epigenetic mark that propagates centromere identity through replication and cell division (PubMed:11483958, PubMed:16839185)
Forms a nucleosome-like histone octamer containing two molecules each of H2A, H2B, cid and H4 assembled in one cid-H4 heterotetramer and two H2A-H2B heterodimers (By similarity). The cid-H4 heterotetramer is more compact and structurally more rigid than corresponding H3-H4 heterotetramers (By similarity). Interacts with the condensin subunit Cap-G (PubMed:15592865). Interacts with Chrac-14…
Nucleus, Chromosome, centromere, kinetochore
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