1 unit equals 1 nanogram of purified protein. 100 units are sufficient for reconstituted in vitro transcription assay and 500 units are sufficient for protein-protein interactions assay detected by immunoblot. For research use only.
Formulation and Storage
Protein is in 20 mM Tris-Cl (pH 8.0), 20% Glycerol, 100 mM KCl, 1 mM DTT and 0.2 mM EDTA buffer and kept at -800C. Avoid repeated freeze thaw cycles.
Background
TFIID is a multiprotein complex with a molecular mass of around 750 kDa that directs pre-initiation complex assembly on both TATA box-containing and TATA-less promoters (1). It consists of TATA-binding protein (TBP) and a number of TBP associated factors (TAFs) (2). TBP alone can replace TFIID in a reconstituted in vitro transcription system (3) but only the TFIID complex can mediate transcriptional activation (4). TAFII250, the largest subunit of TFIID contains protein kinase (5) and histone acetyltransferase (6) activities linking transcriptional initiation/activation with chromatin modification. In addition, multiple serine/threonine phosphorylations of TBP and TAFs selectively inhibit the ability of TFIID to mediate transcriptional activation (7). Native TFIID complex is isolated from HeLa nuclear extract after several chromatographic purification steps. Purified TFIID can be applied for in vitro transcription assays, DNA-protein and protein-protein interaction assays. The TFIID protein complex is 60%-70% pure based on SDS-PAGE gel analysis and is devoid of most general transcription factors.
References
1. Matsui, T., et al., (1980). J. Biol. Chem. 255, 11992-11996 2. Dynlacht, B.D., et al., (1991) Cell 66, 563-576 3. Dikstein, R., et al., (1996). Cell 84, 781-790 4. Buratowski, S., et al., (1988) Nature 334, 37-42 5. Pugh, B.F., et al., (1990) Cell 61, 1187-1197 6. Mizzen, C. A., et al., (1996). Cell 87, 1261-1270 7. Segil, N., et al., (1996). Genes Dev. 10, 2389-2400
DISCLAIMER
This products is recommended For RESEARCH USE ONLY and is Not qualified for Use in Diagnostic or Therapeutic Procedures.
