|PROSITE documentation PDOC51134|
In eukaryotes the initiation of transcription of protein encoding genes by the polymerase II complexe (Pol II) is modulated by general and specific transcription factors. The general transcription factors operate through common promoters elements (such as the TATA box). At least seven different proteins associate to form the general transcription factors: TFIIA, -IIB, -IID, -IIE, -IIF, -IIG, and -IIH .
TFIIB and TFIID are responsible for promoter recognition and interaction with pol II; together with Pol II, they form a minimal initiation complex, capable of transcription under certain conditions. The TATA box of a Pol II promoter is bound in the initiation complex by the TBP subunit of TFIID, which bends the DNA around the C-terminal domain of TFIIB (see <PDOC00624>) whereas the N-terminal zinc finger of TFIIB interacts with Pol II [2,3].
The TFIIB zinc finger adopts a zinc ribbon fold characterized by two β-haipins forming two structurally similar zinc-binding sub-sites (see <PDB:1PFT>) . The zinc finger contacts the rbp1 subunit of Pol II through its dock domain, a conserved region of about 70 amino acids located close to the polymerase active site [5,6]. In the Pol II complex this surface is located near the RNA exit groove . Interestingly this sequence is best conserved in the three polymerases that utilize a TFIIB-like general transcription factor (Pol II, Pol III, and archaeal RNA polymerase) but not in Pol I .
The profile we developed covers the whole TFIIB zinc finger.Last update:
June 2005 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|Title||The basic RNA polymerase II transcriptional machinery.|
|Source||Gene Expr. 2:81-91(1992).|
|2||Authors||Buratowski S. Zhou H.|
|Title||Functional domains of transcription factor TFIIB.|
|Source||Proc. Natl. Acad. Sci. U.S.A. 90:5633-5637(1993).|
|3||Authors||Ha I. Roberts S. Maldonado E. Sun X. Kim L.U. Green M. Reinberg D.|
|Title||Multiple functional domains of human transcription factor IIB: distinct interactions with two general transcription factors and RNA polymerase II.|
|Source||Genes Dev. 7:1021-1032(1993).|
|4||Authors||Zhu W. Zeng Q. Colangelo C.M. Lewis M. Summers M.F. Scott R.A.|
|Title||The N-terminal domain of TFIIB from Pyrococcus furiosus forms a zinc ribbon.|
|Source||Nat. Struct. Biol. 3:122-124(1996).|
|5||Authors||Bushnell D.A. Westover K.D. Davis R.E. Kornberg R.D.|
|Title||Structural basis of transcription: an RNA polymerase II-TFIIB cocrystal at 4.5 Angstroms.|
|6||Authors||Tubon T.C. Tansey W.P. Herr W.|
|Title||A nonconserved surface of the TFIIB zinc ribbon domain plays a direct role in RNA polymerase II recruitment.|
|Source||Mol. Cell. Biol. 24:2863-2874(2004).|