Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P20226 (TATA-binding protein)
 1,297 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dimerization is proposed to be a regulatory mechanism for TATA-binding protein (TBP) activity both in vitro and in vivo. The reversible dimer-monomer transition of TBP is influenced by the buffer conditions in vitro. Using in vitro chemical cross-linking, we found yeast TBP (yTBP) to be largely monomeric in the presence of the divalent cation Mg2+, even at high salt concentrations. Apparent molecular mass of yTBP at high salt with Mg2+, run through a gel filtration column, was close to that of monomeric yTBP. Lowering the monovalent ionic concentration in the absence of Mg2+, resulted in dimerization of TBP. Effect of Mg2+ was seen at two different levels: at higher TBP concentrations, it suppressed the TBP dimerization and at lower TBP levels, it helped keep TBP monomers in active conformation (competent for binding TATA box), resulting in enhanced TBP-TATA complex formation in the presence of increasing Mg2+. At both the levels, activity of the full-length TBP in the presence of Mg2+ was like that reported for the truncated C-terminal domain of TBP from which the N-terminus is removed. Therefore for full-length TBP, intra-molecular interactions can regulate its activity via a similar mechanism.
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PMID:Regulation of activity of the yeast TATA-binding protein through intra-molecular interactions. 1279 88

The general transcription factor IID (TFIID) is a key target for regulation because its binding to a core promoter is the nucleating step in transcription complex assembly. Many eukaryotic activators stimulate recruitment of the TFIID when its concentration is made limiting at a promoter in vitro. Magnesium-agarose gels can separate large complexes containing TFIID, TFIIA (the DA complex), and TFIIB (the DAB complex) and permit a quantitative measurement of how activators stimulate assembly of such complexes. The advantage of the electrophoretic mobility shift assay (EMSA) is that the reactions can be performed under subsaturating conditions where a TFIID footprint might not be observed. Typically, the activator is incubated with a 32P-labeled DNA template, recombinant TFIIA purified from Escherichia coli, and immunopurified TFIID. After incubation, the samples are electrophoresed on magnesium-containing agarose gels, dried onto DEAE-cellulose paper, and autoradiographed. The DNA-protein complexes containing TFIID migrate with reduced mobility on magnesium-agarose gels both because of the large size of the complex and because the TATA-binding protein (TBP) subunit induces a sharp bend in the DNA, causing altered mobility. By comparing the binding of TFIID over a wide concentration range, with and without activator, one can assess whether the activator interacts with TBP or with one of the TBP-associated factors (TAFIIs). Additional factors such as TFIIA and TFIIB can be added subsequently to quantify their contributions to assembly of the transcription complex.
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PMID:Magnesium-agarose electrophoretic mobility shift assay (EMSA) of transcription factor IID binding to DNA. 2104 87