General transcription and DNA repair factor IIH helicase/translocase subunit XPB (ERCC3) is a 782-residue protein from Homo sapiens. This is its AlphaFold structure prediction, created 1 Aug 2025. UniProt accession: P19447.
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The mean pLDDT of this model is 75.9 (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 | 29% |
| 70 to 90 | Confident: backbone generally right | 45% |
| 50 to 70 | Low: treat with caution | 9% |
| Below 50 | Very low: often disordered regions | 17% |
What pLDDT means and how to read it
ATP-dependent 3'-5' DNA helicase/translocase (PubMed:17466626, PubMed:27193682, PubMed:33902107, PubMed:8465201, PubMed:8663148). Binds dsDNA rather than ssDNA, unzipping it in a translocase rather than classical helicase activity (PubMed:27193682, PubMed:33902107). Component of the general transcription and DNA repair factor IIH (TFIIH) core complex (PubMed:10024882, PubMed:17466626, PubMed:8157004, PubMed:8465201). When complexed to CDK-activating kinase (CAK), involved in RNA transcription by RNA polymerase II. The ATPase activity of XPB/ERCC3, but not its helicase activity, is required for DNA opening; it may wrap around the damaged DNA wedging it open, causing localized melting that…
Component of the 7-subunit TFIIH core complex composed of XPB/ERCC3, XPD/ERCC2, GTF2H1, GTF2H2, GTF2H3, GTF2H4 and GTF2H5, which is active in NER. The core complex associates with the 3-subunit CDK-activating kinase (CAK) module composed of CCNH/cyclin H, CDK7 and MNAT1 to form the 10-subunit holoenzyme (holo-TFIIH) active in transcription (PubMed:8663148, PubMed:9852112). Interacts with PUF60…
Nucleus
Compare the prediction with experimentally determined structures of the same protein:
| PDB ID | Method | Resolution | Chains and residues |
|---|---|---|---|
| 4ERN | X-ray | 1.8 Å | A=494-782 |
| 7NVV | EM | 2.9 Å | 7=1-782 |
| 28JM | EM | 3.29 Å | A=1-782 |
| 7EGB | EM | 3.3 Å | 6=1-782 |
| 8EBU | EM | 3.3 Å | A=1-782 |
| 9PD3 | EM | 3.3 Å | A=1-782 |
| 28JS | EM | 3.32 Å | A=1-782 |
| 9PD4 | EM | 3.4 Å | A=1-782 |
| 6RO4 | EM | 3.5 Å | A=1-782 |
| 7AD8 | EM | 3.5 Å | A=1-782 |
| 9XYU | EM | 3.5 Å | A=1-782 |
| 28KE | EM | 3.6 Å | A=1-782 |
| 8EBX | EM | 3.6 Å | A=1-782 |
| 8EBY | EM | 3.6 Å | A=1-782 |
| 6NMI | EM | 3.7 Å | A=34-730 |
| 7EGC | EM | 3.9 Å | 6=1-782 |
| 7NVX | EM | 3.9 Å | 7=1-782 |
| 8EBT | EM | 3.9 Å | A=52-721 |
| 28JV | EM | 3.91 Å | A=1-782 |
| 8BVW | EM | 4.0 Å | 0=1-772 |
Showing 20 of 52 experimental structures (best resolution first).
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