Mitotic checkpoint serine/threonine-protein kinase BUB1 beta (BUB1B) is a 1050-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: O60566.
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The mean pLDDT of this model is 63.6 (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 | 15% |
| 70 to 90 | Confident: backbone generally right | 34% |
| 50 to 70 | Low: treat with caution | 14% |
| Below 50 | Very low: often disordered regions | 37% |
What pLDDT means and how to read it
Kinase which is a component of the mitotic checkpoint complex (MCC), which inhibits APC/C and delays chromosome segregation until all chromosomes are properly attached to the mitotic spindle (PubMed:27509861, PubMed:31201382). The MCC, which consists of CDC20, MAD2L1/MAD2, BUB1B/BUBR1 and BUB3, is a key player of the spindle assembly checkpoint (PubMed:11702782, PubMed:14706340, PubMed:15020684, PubMed:27509861, PubMed:31201382). The MCC-bound APC/C complex is inactive and this delays the metaphase/anaphase transition (PubMed:10477750, PubMed:27509861). When the spindle assembly checkpoint is silenced, the MCC-APC/C complex recruits the E2 enzyme UBCH10 and triggers the auto-ubiquitination…
Component of the mitotic checkpoint complex (MCC), composed of CDC20, MAD2L1/MAD2, BUB1B/BUBR1 and BUB3; within the complex interacts with CDC20 and MAD2L1/MAD2 in its closed conformation (PubMed:11702782, PubMed:29162720, PubMed:33094908, PubMed:27509861). The MCC associates with CDC20-APC/C to form the CDC20-APC/C-MCC complex; within the complex BUB1B/BUBR1 interacts with both the CDC20 in MCC…
Cytoplasm, Nucleus, Chromosome, centromere, kinetochore, Cytoplasm, cytoskeleton, microtubule organizing center, centrosome
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 2WVI | X-ray | 1.8 Å | A=57-220 |
| 3SI5 | X-ray | 2.2 Å | A/B=57-220 |
| 5JJA | X-ray | 2.35 Å | C/D=647-720 |
| 4GGD | X-ray | 2.44 Å | C/D=20-42 |
| 5K6S | X-ray | 2.79 Å | B=663-681 |
| 5SWF | X-ray | 2.82 Å | B=668-676 |
| 6TLJ | EM | 3.8 Å | S=1-1050 |
| 5LCW | EM | 4.0 Å | S=1-560 |
| 5KHU | EM | 4.8 Å | Q=1-1050 |
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