TATA-box-binding protein TBP

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. 

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... 

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.

The rRNA promoter consists of a core element which straddles the transcriptional start site (designated as position +1) from residues -31 to +6 plus an upstream control element (UCE) about 50-80 bp in size and located about 100 bp upstream from the start site (i.e. at position -100 Fig. 4b). A transcription factor called upstream binding factor (UBF) binds both to the UCE as well as to a region next to and overlapping with the core element. Interestingly, TATA box binding protein (TBP see Topic G6), also binds to the rRNA promoter (in fact, TBP is required for initiation by all three eukaryotic RNA polymerases). The UBF and TBP transcription factors interact with each other and with RNA Pol I to form a transcription initiation complex. The RNA Pol I then transcribes... 

Interaction of the TATA-box-binding protein (TBP) with promoter DNA is rather inefficient and appears to be the rate-limiting step for the start of transcription. TBP must actually dissociate first from the TFIID complex before it can bind to the TATA-box DNA. Dissociation of TBP is facilitated by the dimeric structure of TFIID, when it is not bound to DNA, and by the interaction of TBP with TFIIA. 

TATA box-binding protein-associated factor 10, a component of the general transcription factor complex TFllD and the TATA box-binding protein (TBP)-free TAF-containing complex... 

K. Miaskiewicz and R.L. Omstein. DNA binding by TATA-box binding protein (TBP) a molecular dynamics computational study. J. Biomol. Struct. Dyn. 13 (1996) 593-600. 

The TATA-box-bInding protein (TBP). a component of TFIID, recognizes the TATA box.] After assembly, TFIIH opens the DNA double helix and phosphorylates the carboxyl-termina domain (CTD). allowing the polymerase to leave the promoter and begin transcription. 

DNA-binding sequences before these sequences become sequestered into nu-cleosomes, which are inherently transcriptionally repressive (Wolffe, 1991, 1994). Consistent with this proposal is the observation that confocal microscopy indicated that the nuclear concentration of transcription factors such as TATA-box binding protein (TBP) and Spl (Worrad et al., 1994) as well as oct-4 and etl-1 (Worrad and Schultz, unpublished observations) was higher in the male pronucleus than the female pronucleus. Such a difference could account for greater level of transcription supported by the male pronucleus. Nevertheless, it was also possible that the transcriptional capacity of the female pronucleus was inherently less than that of the male pronucleus. This does not seem to be the case, however, since BrUTP incorporation by the female pronucleus in a parthenogenetically activated egg was equivalent to that of the combined BrUTP incorporation of the male and female pronuclei in a fertilized egg (Aoki et al., 1997). Likewise, the amount of TBP sequestered by the female pronucleus in a parthenogenetically activated egg was much greater than that of a fertilized egg and essentially equivalent to that present in both the male and female pronuclei. Thus, when the female pronucleus does not have to compete with the male pronucleus for transcription factors, the female pronucleus can readily sequester the maternally derived transcription factors. 

Worrad, D.M., Ram, P.T., and Schultz, R.M. (1994). Regulation of gene expression in the mouse oocyte and early preimplantation embryo Developmental changes in Spl and TATA box-binding protein, TBP. Development 120 2347-2357. 

Fig. 1.21 I nitial protein complexes formed at the TATA box and the initiation region Selection of the transcription start site is mediated either by the TATA box or the initiation region INR. The TATA box is bound by the TATA box binding protein TBP in cooperation with the general transcription factors IIA and MB. In the absence of a TATA box, transcription initiation requires binding of the TAF 250 and TAFM150 to the INR.

Many general repressors function via components of the basal transcription machinery, with the TATA box-binding protein TBP as the major target. Repressors like NC2 are known that bind to the TBP on the promotor and can prevent RNA polymerase II holoenzyme from assembling into the initiation complex. In this way, a general repression of class II genes can be achieved. 

Figure 4.14. Crystal structure of the human TATA-box binding protein (TBP) with DNA, downloaded from the Protein Data Band (ID 1TGH) and visualized in spacefilling format in RasMol [116], The two strands of the DNA are blue and aqua, the protein is yehow-gteen, and waters of hydration are red. (See color plates).

TFIID (which contains the TATA-box binding protein, TBP) binds to the TATA box. TFIIA and TFIIB then bind, followed by recruitment of RNA polymerase II and TFIIF. TFIIH and TFIIE then bind to form the preinitiation complex (PIC). Kinases phosphorylate the C-terminal domain of Pol II, leading to the open complex in which the DNA strands are separated. RNA is produced during elongation as Pol II and TFIIF leave the promoter and the other general transcription factors behind. Pol II dissociates during the termination phase, and the CTD is dephosphorylated. Pol II/TFIIF is then recycled to bind to another promoter. 

TATA-box binding protein (TBP) a part of one of the general transcription factors found in eukaryotic transcription it binds to the TATA-box portion of the promoter (11-4)... 

TATA box-binding protein [TBP, PDB code, Icdw (Nikolov et al., 1996) ], where mostly nonpolar protein side chains contact the bases and sugars in the minor groove of DNA. A large distortion of the double helix pushes... 

Describe the role of TATA-box-binding protein (TBP, TFIID) in forming the basal transcription apparatus. What properties does TBP confer on this apparatus ... 

The TATA box-binding protein (TBP) is a basic transcription factor absolutely required for transcription by the three nuclear RNA polymerases (7). RNA polymerase II transcription of many protein coding genes requires direct contact of the DNA by TBP, at a sequence called the TATA box, which is located approximately 30 basepairs upstream of the transcription initiation site (2). This complex directs the assembly of the remaining basic transcription factors into a preinitiation complex (i). 

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