IPR004855
Transcription factor IIA, alpha/beta subunit
InterPro entry
Short name | TFIIA_asu/bsu |
Description
Transcription factor IIA (TFIIA) is one of several factors that form part of a transcription pre-initiation complex along with RNA polymerase II, the TATA-box-binding protein (TBP) and TBP-associated factors, on the TATA-box sequence upstream of the initiation start site. After initiation, some components of the pre-initiation complex (including TFIIA) remain attached and re-initiate a subsequent round of transcription. TFIIA binds to TBP to stabilise TBP binding to the TATA element. TFIIA also inhibits the cytokine HMGB1 (high mobility group 1 protein) binding to TBP
[2], and can dissociate HMGB1 already bound to TBP/TATA-box.
Human and Drosophila TFIIA have three subunits: two large subunits, LN/alpha and LC/beta, derived from the same gene, and a small subunit, S/gamma. Yeast TFIIA has two subunits: a large TOA1 subunit that shows sequence similarity to the N-terminal of LN/alpha and the C-terminal of LC/beta, and a small subunit, TOA2 that is highly homologous with S/gamma. The conserved regions of the large and small subunits of TFIIA combine to form two domains: a four-helix bundle (helical domain) composed of two helices from each of the N-terminal regions of TOA1 and TOA2 in yeast; and a β-barrel (β-barrel domain) composed of β-sheets from the C-terminal regions of TOA1 and TOA2
[3].
This entry represents the precursor that yields both the alpha and beta subunits of TFIIA. The TFIIA heterotrimer is an essential general transcription initiation factor for the expression of genes transcribed by RNA polymerase II
[1].
References
1.A transcription reinitiation intermediate that is stabilized by activator. Yudkovsky N, Ranish JA, Hahn S. Nature 408, 225-9, (2000). View articlePMID: 11089979
2.TFIIA abrogates the effects of inhibition by HMGB1 but not E1A during the early stages of assembly of the transcriptional preinitiation complex. Dasgupta A, Scovell WM. Biochim. Biophys. Acta 1627, 101-10, (2003). View articlePMID: 12818428
3.Crystal structure of a yeast TFIIA/TBP/DNA complex. Tan S, Hunziker Y, Sargent DF, Richmond TJ. Nature 381, 127-51, (1996). View articlePMID: 8610010
GO terms
biological process
molecular function
- None
cellular component
Representative structure
1nh2: Crystal structure of a yeast TFIIA/TBP/DNA complex