Transcription factor TFIIA is a nuclearprotein involved in the RNA polymerase II-dependent transcription of DNA.[1] TFIIA is one of several general (basal) transcription factors (GTFs) that are required for all transcription events that use RNA polymerase II. Other GTFs include TFIID, a complex composed of the TATA binding protein TBP and TBP-associated factors (TAFs), as well as the factors TFIIB, TFIIE, TFIIF, and TFIIH. Together, these factors are responsible for promoter recognition and the formation of a transcription preinitiation complex (PIC) capable of initiating RNA synthesis from a DNA template.
TFIIA interacts with the TBP subunit of TFIID and aids in the binding of TBP to TATA-box containing promoter DNA.[2][3] Interaction of TFIIA with TBP facilitates formation of and stabilizes the preinitiation complex. Interaction of TFIIA with TBP also results in the exclusion of negative (repressive) factors that might otherwise bind to TBP and interfere with PIC formation. TFIIA also acts as a coactivator for some transcriptional activators, assisting with their ability to increase, or activate, transcription. The requirement for TFIIA in vitro transcription systems has been variable, and it can be considered either as a GTF and/or a loosely associated TAF-like coactivator. Genetic analysis in yeast has shown that TFIIA is essential for viability.
Structureedit
TFIIA is a heterodimer with two subunits: one large unprocessed (subunit 1, or alpha/beta; gene name GTF2A1) and one small (subunit 2, or gamma; gene name GTF2A2).[4][5] It was originally believed to be a heterotrimer of an alpha (p35), a beta (p19) and a gamma subunit (p12). In humans, the sizes of the encoded proteins are approximately 55 kD and 12 kD. Both genes are present in species ranging from humans to yeast, and their protein products interact to form a complex composed of a beta barreldomain and an alpha helical bundle domain. It is the N-terminal and C-terminal regions of the large subunit that participate in interactions with the small subunit. These regions are separated by another domain whose sequence is always present in large subunits from various species but whose size varies and whose sequence is poorly conserved. A second gene encoding a large TFIIA subunit has been found in some higher eukaryotes. This gene, ALF/TFIIAtau (gene name GTF2A1LF) is expressed only in oocytes and spermatocytes, suggesting it has a TFIIA-like regulatory role for gene expression only in germ cells.
Referencesedit
^Høiby T, Zhou H, Mitsiou DJ, Stunnenberg HG (2007). "A facelift for the general transcription factor TFIIA". Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression. 1769 (7–8): 429–36. doi:10.1016/j.bbaexp.2007.04.008. hdl:2066/34866. PMID 17560669.
^Tang H, Sun X, Reinberg D, Ebright RH (February 1996). "Protein-protein interactions in eukaryotic transcription initiation: structure of the preinitiation complex". Proceedings of the National Academy of Sciences of the United States of America. 93 (3): 1119–24. Bibcode:1996PNAS...93.1119T. doi:10.1073/pnas.93.3.1119. PMC40041. PMID 8577725.
^Louder RK, He Y, López-Blanco JR, Fang J, Chacón P, Nogales E (March 2016). "Structure of promoter-bound TFIID and model of human pre-initiation complex assembly". Nature. 531 (7596): 604–9. Bibcode:2016Natur.531..604L. doi:10.1038/nature17394. PMC4856295. PMID 27007846.
^DeJong J, Roeder RG (November 1993). "A single cDNA, hTFIIA/alpha, encodes both the p35 and p19 subunits of human TFIIA". Genes & Development. 7 (11): 2220–34. doi:10.1101/gad.7.11.2220. PMID 8224848.
^Ozer J, Moore PA, Bolden AH, Lee A, Rosen CA, Lieberman PM (October 1994). "Molecular cloning of the small (gamma) subunit of human TFIIA reveals functions critical for activated transcription". Genes & Development. 8 (19): 2324–35. doi:10.1101/gad.8.19.2324. PMID 7958899.
External linksedit
Transcription+Factor+TFIIA at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
March 17, 2024
transcription, factor, transcription, factor, tfiia, nuclear, protein, involved, polymerase, dependent, transcription, tfiia, several, general, basal, transcription, factors, gtfs, that, required, transcription, events, that, polymerase, other, gtfs, include, . Transcription factor TFIIA is a nuclear protein involved in the RNA polymerase II dependent transcription of DNA 1 TFIIA is one of several general basal transcription factors GTFs that are required for all transcription events that use RNA polymerase II Other GTFs include TFIID a complex composed of the TATA binding protein TBP and TBP associated factors TAFs as well as the factors TFIIB TFIIE TFIIF and TFIIH Together these factors are responsible for promoter recognition and the formation of a transcription preinitiation complex PIC capable of initiating RNA synthesis from a DNA template general transcription factor IIA 1 19 37kDaIdentifiersSymbolGTF2A1NCBI gene2957HGNC4646OMIM600520RefSeqNM 201595UniProtP52655Other dataLocusChr 14 q31Search forStructuresSwiss modelDomainsInterProgeneral transcription factor IIA 2 12kDaIdentifiersSymbolGTF2A2NCBI gene2958HGNC4647OMIM600519RefSeqNM 004492UniProtP52657Other dataLocusChr 15 q21 3Search forStructuresSwiss modelDomainsInterPro Contents 1 Functions 2 Structure 3 References 4 External linksFunctions editTFIIA interacts with the TBP subunit of TFIID and aids in the binding of TBP to TATA box containing promoter DNA 2 3 Interaction of TFIIA with TBP facilitates formation of and stabilizes the preinitiation complex Interaction of TFIIA with TBP also results in the exclusion of negative repressive factors that might otherwise bind to TBP and interfere with PIC formation TFIIA also acts as a coactivator for some transcriptional activators assisting with their ability to increase or activate transcription The requirement for TFIIA in vitro transcription systems has been variable and it can be considered either as a GTF and or a loosely associated TAF like coactivator Genetic analysis in yeast has shown that TFIIA is essential for viability Structure editTFIIA is a heterodimer with two subunits one large unprocessed subunit 1 or alpha beta gene name GTF2A1 and one small subunit 2 or gamma gene name GTF2A2 4 5 It was originally believed to be a heterotrimer of an alpha p35 a beta p19 and a gamma subunit p12 In humans the sizes of the encoded proteins are approximately 55 kD and 12 kD Both genes are present in species ranging from humans to yeast and their protein products interact to form a complex composed of a beta barrel domain and an alpha helical bundle domain It is the N terminal and C terminal regions of the large subunit that participate in interactions with the small subunit These regions are separated by another domain whose sequence is always present in large subunits from various species but whose size varies and whose sequence is poorly conserved A second gene encoding a large TFIIA subunit has been found in some higher eukaryotes This gene ALF TFIIAtau gene name GTF2A1LF is expressed only in oocytes and spermatocytes suggesting it has a TFIIA like regulatory role for gene expression only in germ cells References edit Hoiby T Zhou H Mitsiou DJ Stunnenberg HG 2007 A facelift for the general transcription factor TFIIA Biochimica et Biophysica Acta BBA Gene Structure and Expression 1769 7 8 429 36 doi 10 1016 j bbaexp 2007 04 008 hdl 2066 34866 PMID 17560669 Tang H Sun X Reinberg D Ebright RH February 1996 Protein protein interactions in eukaryotic transcription initiation structure of the preinitiation complex Proceedings of the National Academy of Sciences of the United States of America 93 3 1119 24 Bibcode 1996PNAS 93 1119T doi 10 1073 pnas 93 3 1119 PMC 40041 PMID 8577725 Louder RK He Y Lopez Blanco JR Fang J Chacon P Nogales E March 2016 Structure of promoter bound TFIID and model of human pre initiation complex assembly Nature 531 7596 604 9 Bibcode 2016Natur 531 604L doi 10 1038 nature17394 PMC 4856295 PMID 27007846 DeJong J Roeder RG November 1993 A single cDNA hTFIIA alpha encodes both the p35 and p19 subunits of human TFIIA Genes amp Development 7 11 2220 34 doi 10 1101 gad 7 11 2220 PMID 8224848 Ozer J Moore PA Bolden AH Lee A Rosen CA Lieberman PM October 1994 Molecular cloning of the small gamma subunit of human TFIIA reveals functions critical for activated transcription Genes amp Development 8 19 2324 35 doi 10 1101 gad 8 19 2324 PMID 7958899 External links editTranscription Factor TFIIA at the U S National Library of Medicine Medical Subject Headings MeSH Retrieved from https en wikipedia org w index php title Transcription factor II A amp oldid 1136190884, wikipedia, wiki, book, books, library,
