TFIIF
TFIIF is a eukaryotic transcription factor often found associated with RNA polymerase II. It plays a role in the formation of the Pre-Initiation complex (PIC) prior to the initiation of gene transcription. Allthough eukaryotic transcription initiation is more complex than in bacteria the function of the corresponding transcription factors can be compared. Parts of TFIIF share structural homology with sigma factor in bacteria. [1]
- The human version of TFIIF has two subunits.[2]
- A major role of TFIIF in the PIC is the destabilisation of non-specific interactions between DNA and the RNA polymerase II. [1]
- It also interacts with TFIIB and aids the recruitment of TFIIE and TFIIH. Interactions between RNA polymerase II and the TATA binding protein (TBP) domain of TFIID are stabilised by TFIIF. [3]
- Experiments involving the in vitro assembly of the PIC have revealed lots about the functions of eukaryotic transcription factors. Structure comparisons between mediator-RNA polymerase II complexes with and without the presence of TFIIF have shown that TFIIF plays a part in maintaining the directionality of RNA polymerase II during the pre-initiation stage of transcription.[4]
- During transcriptional elongation TFIIF moves down the DNA template with RNA polymerase II.
References
- ↑ 1.0 1.1 Alberts, Johnson, Lewis, Raff, Roberts, Walter. (2008) Molecular Biology of The Cell. 5th Edition. p340-1 Cite error: Invalid
<ref>tag; name "null" defined multiple times with different content - ↑ Whitehall S. (2011) CMB2002 lecture slides
- ↑ Alberts, Johnson, Lewis, Raff, Roberts, Walter. (2008) Molecular Biology of The Cell. 5th Edition. p340-1
- ↑ Bernecky C, Grob P, Ebmeier CC, Nogales E, Taatjes DJ. (2011) 'Molecular architecture of the human Mediator-RNA polymerase II-TFIIF assembly' PLoS Biol. 2011 Mar;9(3):e1000603