Transcription factor IIB

Sutrias-Grau, M., Bianchi, M.E., and Bernues, J. (1999) High mobility group protein 1 interacts specifically with the core domain of human TATA box-binding protein and interferes with transcription factor IIB within the pre-initiation complex. J. Biol. Chem. 274, 1628-1634. 

Figure 28-13 (A) Stereoscopic ribbon drawing of the phyloge-netically conserved 180-residue C-terminal portion of the TATA-binding protein (TBP) from Arabidopsis thaliana. The sequence consists of two direct repeats, giving the protein an approximate twofold symmetry. From Nikolov et al.337 (B) Structure of the corresponding C-terminal core (residues 155-335) of the human TATA-binding protein (TBP) bound to the TATA sequence of a promoter in adenovirus DNA. From Nikolov et al.327 (C) Structure of human transcription factor IIB bound to a TBP from Arabidopsis thaliana, which, in turn, is bound to an adenovirus TATA sequence. Hypothetical B DNA extensions have been modeled at both ends of the DNA segment. The +1 at the left end is the transcription start site and the —43 upstream end is to the right. From Nikolov et al.338 Courtesy of Stephen K. Burley.

The zinc-ribbon motif is found in a diverse group of proteins with limited sequence similarity and includes proteins involved in transcription (e.g. Transcription Factor IIB" ) and translation (the G domain of the y-subunit of the heterotrimeric translation initiation factor In TFIIB, the surface... 

Jurutka, P. W., Hsieh, j.-C., Remus, L. S., Whitfield, G. K., Thomp.son, P. D., Haussler, C., Blanco, J C, Ozato, K and Haussler, M. R, (1997). Mutations in the 1,25 dihydroxyvi-tamin II3 receptor identifying C-terminal amino acids required for transcriptional activation that are functionally dissociated from hormone binding, hetenodimeric DMA binding, and interaction with basal transcription factor IIB, in vitro. J. Biol. Chsm. 272, 14592-14599,... 

The zinc-ribbon motif is found in a diverse group of proteins with limited sequence similarity and includes proteins involved in transcription (e.g. Transcription Factor IIB ) and translation (the G domain of the y-subunit of the heterotrimeric translation initiation factor elFZ). In TFIIB, the surface of the ribbon domain is conserved and is essential for the recruitment of RNA polymerase II (Pol II) to the Preinitiation Complex (PIC). The GCM (glia cell missing) transcriptional regulators make novel use of a ribbon-like zinc complex to bind to DNA in an unusual way. Here, one edge of a live-stranded antiparallel /3-sheet inserts into the major groove. The middle three antiparallel /3-strands of the live-stranded... 

Killeen, M., Coulombe, B., and Greenblatt, J. (1992). Recombinant TBP, transcription factor IIB, and RAP30 are sufficient for promoter recognition by mammalian RNA polymerase II. J. Biol. Chem. 267(14), 9463-9466. 

Lagrange, T., Kapanidis, A. N., Tang, H., Reinberg, D., and Ebright, R. H. (1998). New core promoter element in RNA polymerase II dependent transcription sequence specific DNA binding by transcription factor IIB. Genes Dev. 12(1), 34-44. 

Leuther, K. K., Bushnell, D. A., and Kornberg, R. D. (1996). Two-dimensional crystallography of transcription factor IIB- and IIE-RNA polymerase II complexes implications for start site selection and initiation complex formation. Cell 85, 773-779. 

Recently, this system was used to identify several factors putatively involved in the mechanism of steroid hormone-mediated gene transcription. In a two-hybrid screen to identify factors that interact with the vitamin D receptor (VDR), we isolated transcription factor IIB (TFIIB) as a VDR-mteractive clone (2). The interaction of VDR, retinoic-acid receptors and other steroid-hormone receptors with TFIIB may represent a fundamental step in the mechanism of transcription mediated by the nuclear-receptor family (3-5) The two-hybrid system has also identified several putative coactivator and corepressor proteins that contact retinoid receptors, thyroid receptors, vitamin D receptors, and other members of the nuclear-receptor family (6-9) Thus, the two-hybrid system is playing an instrumental role in the identification of factors involved in nuclear receptor-mediated gene expression This chapter discusses several procedures and strategies used to establish a two-hybrid system to examine proteins that interact with retinoid receptors, with the VDR, or with nuclear receptors in general. 

The d,-antitrypsin promoter contains a consensus TATA box, a B-recognition element for transcription-activating factor IIB, a hepatocyte nuclear factor 1 site, and two non-tissue-specific regions that increase transcription. There is a 3 enhancer region with five potential binding sites for transcription factors. The specific factors that bind in this area remain to be described. 

B. Coulombe, J. Li and J. Greenblatt. Topological localization of the human transcription factors UA, IIB, TATA box-binding protein, and RNA polymerase U-associated protein 30 on a class U promoter. J Biol Chem 269 (1994) 19962-7. 

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