TATA-box binding protein

Fig. 2. Two views of the stmcture of the TATA-box binding protein (TBP)—DNA complex, where TATA is the nucleotide sequence...

The DNA part of each control module can be divided into three main regions, the core or basal promoter elements, the promoter proximal elements and the distal enhancer elements (Figure 9.1). The best characterized core promoter element is the TATA box, a DNA sequence that is rich in A-T base pairs and located 25 base pairs upstream of the transcription start site. The TATA box is recognized by one of the basal transcription factors, the TATA box-binding protein, TBP, which is part of a multisubunit complex called TFIID. This complex in combination with RNA polymerase 11 and other basal transcription factors such as TFIIA and TFIIB form a preinitiation complex for transcription. 

Figure 9.2 Schematic model for transcriptional activation. The TATA box-binding protein, which bends the DNA upon binding to the TATA box, binds to RNA polymerase and a number of associated proteins to form the preinitiation complex. This complex interacts with different specific transcription factors that bind to promoter proximal elements and enhancer elements.

The general transcription factor TFllD is believed to be the key link between specific transcription factors and the general preinitiation complex. However, the purification and molecular characterization of TFllD from higher eucaryotes have been hampered by its instability and heterogeneity. All preparations of TFllD contain the TATA box-binding protein in combination with a variety of different proteins called TBP-associated factors, TAFs. When the preinitiation complex has been assembled, strand separation of the DNA duplex occurs at the transcription start site, and RNA polymerase II is released from the promoter to initiate transcription. However, TFIID can remain bound to the core promoter and support rapid reinitiation of transcription by recruiting another molecule of RNA polymerase. 

Figure 9.3 Comparison of the consensus nucleotide sequence of the TATA box (a) and the sequences of the DNA fragments used in the crystal structure determinations of the TATA box-binding proteins from yeast (b) and the plant Arabidopsis thaliana (c).

Nikilov, D.B., et al. Crystal structure of TFllD TATA-box binding protein. Nature 360 40-46, 1992. 

The TATA box-binding protein is ubiquitous The three-dimensional structures of... 

In vitro interactions between HMG proteins and the basal transcription machinery have also been reported. Human HMGBl binds to the TATA-box binding protein (TBP) and interferes with the normal binding of TFIIB in the preinitiation complex [154,155], thereby inhibiting TBP function both HMGBl and TFIIB independently enhance binding of TBP to TATA-box DNA [154]. Similarly, Nhp6ap promotes the formation of a complex with TBP and TFIIA at the TATA... 

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. 

HRE - hormone response element TAFs - TBP-associated factors TBP - TATA box-binding protein A-H - basal transcription factors... 

Kosa, P. E, Ghosh, G., DeDecker, B. S. and Sigler, P. B. (1997). The 2.1-A crystal structure of an archaeal preinitiation complex TATA-box-binding protein/transcription factor (II)B core/TATA-box. Proc. Nat. Acad. Sci. USA 94, 6042-6047. 

Fig. 1.16. Bending of DNA in the TATA box. The DNA is kinked in the complex of the TATA box binding protein (yeast) with the 8 base pair TATA box (Kim et al., 1993). The DNA is deformed in the region near the kink the minor groove, which faces the protein, is clearly widened. Molscript drawing (Kraulis, 1991).

Fig. 1.30. Structure of a typical eucaryotic transcription start site. Enhancer elements and UAS elements (UAS upstream activating sequences) are binding sites for positive and negative regulatory DNA-binding proteins. The TATA box is the binding site for the TATA box binding protein (TBP) and serves to position the RNA polymerase holoenzyme on the promoter. For promoters that do not possess a TATA box, this function is fulfilled by an initiator region.

Table 1.L General initiation factors of transcription by RNA polymerase II After Roeder (1996). TAF TATA box binding protein associated factor TBP TATA box binding protein RNA Pol II RNA polymerase II...

TBP TATA box binding protein, TAF TATA box binding protein associated factor, SRB suppressor of RNA polymerase B, CTD C-terminal domain of RNA polymerase II, PC positive cofactor, NC negative cofactor, HMG high mobihty group proteins, UAS upstream activating sequence. 

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