TFIIA

general transcription factor IIA, 1, 19/37kDa
Identifiers
Symbol	GTF2A1
Entrez	2957
HUGO	4646
OMIM	600520
RefSeq	NM_201595
UniProt	P52655
Other data
Locus	Chr. 14 q31

general transcription factor IIA, 2, 12kDa
Identifiers
Symbol	GTF2A2
Entrez	2958
HUGO	4647
OMIM	600519
RefSeq	NM_004492
UniProt	P52657
Other data
Locus	Chr. 15 q21.3

Transcription factor TFIIA is a nuclear protein involved in the RNA polymerase II-dependent transcription of DNA. 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. 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.

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Wikipedia