TFIIH helicase XPD
| TFIIH helicase XPD | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 760 amino acids | |
| Cofactor | Mg 2+ | |
| Identifier | ||
| Gene name | ERCC2 | |
| External IDs | ||
| Enzyme classification | ||
| EC, category | 3.6.4.12 , Helicase | |
| Response type | Hydrolysis, isomerization | |
| Substrate | ATP + ds-DNA | |
| Products | ADP + phosphate + ds-DNA with 'bubble' | |
| Occurrence | ||
| Parent taxon | Animals, mushrooms | |
| Orthologue | ||
| human | House mouse | |
| Entrez | 2068 | 13871 |
| Ensemble | ENSG00000104884 | ENSMUSG00000030400 |
| UniProt | P18074 | O08811 |
| Refseq (mRNA) | NM_000400 | NM_007949 |
| Refseq (protein) | NP_000391 | NP_031975 |
| Gene locus | Chr 19: 45.35 - 45.37 Mb | Chr 7: 19.38 - 19.4 Mb |
| PubMed search | 2068 |
13871
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The TFIIH helicase XPD is an enzyme in the nucleus of fungi and animals that, as part of the transcription factor IIH (TFIIH), catalyzes the opening of the DNA double strand after the pre-initiation complex has been assembled. This reaction step is part of the initiation of the transcription of all eukaryotic genes . In addition, XPD plays a very similar role in DNA repair . Mutations in the human ERCC2 gene, which codes for XPD , can lead to the rare hereditary disease Xeroderma pigmentosum type D, in which the risk of skin cancer is greatly increased, or to Tay syndrome , a rare ichthyosis , or Cockayne syndrome type 2.
The opening of the double strand consumes a molecule of ATP and spans the bases from −10 to +2 with respect to the beginning of the gene. It is supported by untwisting the DNA (so-called negative supercoiling ) with the help of TFIIE . The XPB helicase also takes part in DNA repair . The opened DNA is called a DNA bubble in both cases .
XPB and XPD mimick part of the cell's defense against retroviral infection, a laboratory study. A Chinese study found that a combination of certain XPB and XPD variants increased the risk of lung cancer .
literature
- Beck BD, Hah DS, Lee SH: XPB and XPD between transcription and DNA repair . In: ... Adv Exp Med Biol. . 637, 2008, pp. 39-46. PMID 19181109 .
Individual evidence
- ↑ Homologues at OMA
- ↑ UniProt P18074
- ↑ Reinberg / reactome: RNA Polymerase II Promoter Opening: First Transition ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Joshi-Tope / reactome: Formation of open bubble structure in DNA by helicases ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Gopinathrao / reactome: Assembly of repair proteins at the site of Pol II blockage ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- Jump up ↑ Yoder K, Sarasin A, Kraemer K, McIlhatton M, Bushman F, Fishel R: The DNA repair genes XPB and XPD defend cells from retroviral infection . In: Proc. Natl. Acad. Sci. USA . 103, No. 12, March 2006, pp. 4622-7. doi : 10.1073 / pnas.0509828103 . PMID 16537383 . PMC 1450221 (free full text).
- ↑ Hu Z, Xu L, Shao M, et al. : Polymorphisms in the two helicases ERCC2 / XPD and ERCC3 / XPB of the transcription factor IIH complex and risk of lung cancer: a case-control analysis in a Chinese population . In: Cancer Epidemiol. Biomarkers Prev. . 15, No. 7, July 2006, pp. 1336-40. doi : 10.1158 / 1055-9965.EPI-06-0194 . PMID 16835333 .
