Transcription factor IIH
Transcription factor IIH (TFIIH) is a protein complex in the cell nucleus of vertebrates that is part of the pre-initiation complex for preparing for transcription . In particular, TFIIH is responsible for opening the DNA double strand and releasing the binding of the entire complex to the nuclear promoter so that the transcription machinery can move along the DNA. TFIIH consists of nine individual proteins in humans , which are listed in the following table. When TFIIH binds, the pre-initiation complex is complete and the DNA double strand is opened by the XPB subunit.
During the initiation phase, after the pre-initiation complex has dissolved, the Cdk7 unit phosphorylates the amino acid Ser-5 at the C-terminal end of the polymerase several times, after which the polymerase is able to bind the mRNA capping enzyme .
| Protein name | gene | UniProt | Size (aa) |
comment |
|---|---|---|---|---|
| Cyclin-dependent kinase 7 | CDK7 | P50613 | 346 | Part of the CAK complex |
| Cyclin-H | CCNH | P51946 | 323 | Part of the CAK complex |
| RING finger protein MAT1 | MNAT1 | P51948 | 309 | Part of the CAK complex; Zinc finger domain |
| TFIIH helicase XPD | ERCC2 | P18074 | 760 | Path .: Xeroderma pigmentosum type D; photosensitive trichothiodystrophy ; Cockayne syndrome type II |
| TFIIH helicase XPB | ERCC3 | P19447 | 782 | Path .: Xeroderma pigmentosum type B; photosensitive trichothiodystrophy |
| TFIIH subunit 1 | GTF2H1 | P32780 | 548 | |
| TFIIH subunit 2 | GTF2H2 | Q13888 | 395 | |
| TFIIH subunit 3 | GTF2H3 | Q13889 | 308 | |
| TFIIH subunit 4 | GTF2H4 | Q92759 | 462 |
Individual evidence
- ↑ CORUM: TFIIH
- ↑ Reinberg / reactome: Formation of the closed pre-initiation complex ( 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.
- ↑ Timmers / reactome: RNA Polymerase II Promoter Escape ( 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.
- ↑ Kershnar E, Wu SY, Chiang CM: Immunoaffinity purification and functional characterization of human transcription factor IIH and RNA polymerase II from clonal cell lines that conditionally express epitope-tagged subunits of the multiprotein complexes . In: J. Biol. Chem. . 273, No. 51, December 1998, pp. 34444-53. PMID 9852112 .
- ↑ Buratowski / reactome: Phosphorylation (Ser5) of RNA pol II CTD ( 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.
- ↑ reactome: RNA Polymerase II CTD (phosphorylated) binds to CE ( 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.
