- 1. TFIIA Subunit Gene
- [The three subunits of the TFIIA complex (alpha, bet, and gamma) are encoded by the GTF2A1 and GTF2A2 genes. TFIIA has multiple roles in transcription initiation by RNA polymerase II. First, the association of TFIIA and TBP stabilizes the TBP-TATA element interaction. In so doing, TFIIA also stimulates transcription by displacing TBP-associated repressors and counteracts the ability to inhibit TBP binding to DNA. Second, TFIIA serves as a cofactor for the activators and coactivators. Third, TFIIA is required for the isomerization and extension of TFIID-promoter contacts and for stabilizing interactions between TFIID and initiator sequences. (from PMID 10364255) ( NCI )] (UMLS (NCI) C1336611) =Gene or Genome ;
| - 6. TFIIH Core Subunit Gene
- [Human TFIIH Core Subunit Genes, GTF2H1, GTF2H2, GTF2H3, GTF2H4, ERCC2, and ERCC3, encode six subunits of the nuclear core-TFIIH basal transcription factor. These subunits are involved in transcription-coupled DNA nucleotide excision repair, and basal RNA polymerase II transcription when complexed to CAK (CDK7/Cyclin H/MAT1). Phosphorylated 548-aa 62-kDa GTF2H1 contains 2 BSD domains. The 395-aa 44-kDa GTF2H2 contains a C4-type zinc finger and a VWFA domain. The N-terminus interacts with and regulates XPD, while the C-terminus promotes escape of RNAPII from the promoter. GTF2H2 also interacts with XPB, p62, and p34. Containing a C4-type zinc finger, 303-aa 34-kDa GTF2H3 anchors XPB. ATP-dependent 760-aa 87-kDa ERCC2 DNA helicase anchors CAK to core-TFIIH; interaction with p44 stimulates helicase activity. ERCC3 is a 782-aa 89-kDa ATP-dependent DNA helicase. (NCI) ( NCI )] (UMLS (NCI) C1336615) =Gene or Genome ;
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- 2. TFIID Subunit Gene
- [Human transcription initiation factor TFIID is composed of the TATA-binding protein (TBP) and at least 13 TBP-associated factors (TAFs) that collectively or individually are involved in activator-dependent transcription. Initiation of transcription by RNA polymerase II requires the ordered assembly of basal transcription factors including TFIIA, TFIIB, TATA-binding protein (TBP), TFIIE, TFIIF, TFIIG/TFIIJ, and TFIIH/BTF2 into the TFIID complex. Different activators may interact with specific TAFs to allow the assembly of functionally distinct TFIID complexes that can control transcription of different genes. (NCI) ( NCI )] (UMLS (NCI) C1336612) =Gene or Genome ;
| - 7. TFIIH Subunit Gene
- [For transcription initiation, the nonphosphorylated RNA polymerase II is recruited by TFIIF to the DB complex. This complex is recognized by TFIIE, TFIIH, and TFIIJ to form a transcription-competent complex. Phosphorylation of the C-terminal domain of the largest subunit of RNA polymerase II controls the transition from transcription initiation to elongation and TFIIH contains a kinase activity for phosphorylating this domain. Factors that promote the association of RNA polymerase II with the preinitiation complex stimulate this activity. TFIIE, which is required for the stable association of TFIIH with the preinitiation complex, affects the processivity of TFIIH kinase. TFIIH is a multisubunit factor of at least 5 proteins of 92, 62, 43, 40, and 35 kD. A 52-kD subunit has also been identified as a component of the TFIIH core, along with p89, p62, p44, and p34. (from OMIM, LocusLink and NCI) ( NCI )] (UMLS (NCI) C1336616) =Gene or Genome ;
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- 3. TFIIE Subunit Gene
- [TFIIE Subunit Genes encode 2 subunit proteins of 56 kD and 34 kD. TFIIE is a heterotetramer of 2 alpha and 2 beta subunits, both subunits being required for optimal basal-level transcription. Both subunits are essential to form a stable preinitiation complex. High levels of gene transcription by RNA polymerase II depend on high rates of transcription initiation and reinitiation. Initiation requires recruitment of the complete transcription machinery to a promoter, a process facilitated by activators and chromatin remodeling factors. Reinitiation occurs through a different pathway. After initiation, a subset of the transcription machinery remains at the promoter, forming a platform for assembly of a second transcription complex as a scaffold for formation of a functional reinitiation complex. Formation of this scaffold depends on ATP and TFIIH. Some activators and Mediator may promote high levels of transcription. (from OMIM 189962). ( NCI )] (UMLS (NCI) C1336613) =Gene or Genome ;
| - 8. TFIIIB Subunit Gene
- [Human TFIIIB Subunit Genes, BDP1, BRF1, and, BRF2, encode protein subunits of RNA Polymerase III Transcription Initiation Factor IIIB, required for RNA polymerase III transcription. Transcription begins with TFIIIC recognition of promoter A and B boxes and TFIIIA, TFIIIB, and RNA polymerase III binding. 90-kDa BRF1 contains a C-terminal HMG2-related region and an N-terminal TFII2B-related sequence. 50-kDa BRF2 has a zinc ribbon domain and a core domain, necessary for complex formation with DNA. Involved in nucleation of a polymerase III initiation complex, BRF2 does not directly bind DNA but interacts with TBP, which binds cooperatively to the promoter. TBP, an essential component of TFIIIB, binds the highly charged C-terminus of BRF1. Highly hydrophilic BDP1 contains a DNA-ligase A1 ATP-dependent binding site and several potential phosphorylation sites. (NCI) ( NCI )] (UMLS (NCI) C1336617) =Gene or Genome ;
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- 4. TFIIF Subunit Gene
- [Human TFIIF Subunit Genes, GTF2F1 Gene and GTF2F2 Gene, encode similar alpha (517-aa, 58-kDa, phosphorylated) and beta (249-aa, 28-kDa) subunits of heterodimeric nuclear general transcription initiation factor TFIIF, which binds to and recruits RNA polymerase II to the initiation complex in collaboration with TFIIB. The beta subunit shows ATP-dependent DNA-helicase activity and the region that binds RNA polymerase exhibits similarities with prokaryotic sigma factors. (NCI) ( NCI )] (UMLS (NCI) C1336614) =Gene or Genome ;
| - 9. TFIIIC Subunit Gene
- [RNA polymerases are unable to initiate RNA synthesis in the absence of general transcription factors (GTFs). GTFs assemble in a complex on the DNA promoter and recruit the RNA polymerase. TFIIIC Subunit Genes encode the TFIIIC protein complex that is essential for RNA polymerase III to make a number of small nuclear and cytoplasmic RNAs, including 5S RNA, tRNA, and adenovirus-associated (VA) RNA of both cellular and viral origin. The TFIIIC complex interacts with TFIIIB in the recruitment of RNA polymerase III. Transcription by RNA polymerase III is enhanced during viral infection by the expression of immediate early proteins of adenovirus and pseudorabies virus. (from OMIM 604888) ( NCI )] (UMLS (NCI) C1336618) =Gene or Genome ;
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- 5. TFIIH
- [TFIIH is a multisubunit factor consisting of at least 5 polypeptides of 92, 62, 43, 40, and 35 kD. The nonphosphorylated form of RNA polymerase II is recruited by TFIIF to the DB complex (a DNA-protein complex composed of the TATA-binding protein subunit of TFIID in association with the TATA motif and TFIIB). This complex is then recognized by TFIIE, TFIIH, and TFIIJ to generate a transcription-competent complex. Phosphorylation of the C-terminal domain of the largest subunit of RNA polymerase II controls the transition from transcription initiation to elongation. The general transcription factor TFIIH contains a kinase activity capable of phosphorylating this domain. Factors that promote the association of RNA polymerase II with the preinitiation complex stimulate this activity. TFIIE, which is required for the stable association of TFIIH with the preinitiation complex, affects the processivity of TFIIH kinase. (from OMIM 189972) ( NCI )] (UMLS (NCI) C0172237) =Amino Acid, Peptide, or Protein; Biologically Active Substance ;
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