Transcription Factor IIF, Rap30 + Rap74

• Species: Human
• Expression Host: E. Coli
• Tag: His-tag
• Purity: 90%
• Molecular Weight: 59.3 + 28.3 kDa.
• Gene Accession Number: NM_002096 + NM_004128.

Applications

1 unit equals 1 nanogram of purified protein. 1-10 unit is sufficient for a gel mobility shift assay in a 20 µl reaction to form a D/B/Pol/F complex; 20 units are sufficient for reconstituted transcription assay and 100 units are sufficient for a protein-protein interaction assay. For research use only.

Formulation and Storage

Protein is stored 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.

SYNONYM

BTF4; RAP30; TF2F2; TFIIF.

Background

The transcription factor IIF (TFIIF) is composed of 58 kDa (RAP74) and 26 kDa (RAP30) subunits as a heterodimer, and was first identified through the ability to interact with immobilized RNA polymerase II (1, 2). The Rap74 subunit of TFIIF can be phosphorylated by TAF250 both in vivo and in vitro. The RAP30 subunit of TFIIF contains two distinct regions with sequence similarity to E coli s factors and can deliver RNA polymerase II to the promoter to support transcription initiation in the absence of RAP74 (2, 3).
Recombinant RAP74 protein is isolated from an E. coli strain that carries the coding sequence of human RAP74, the subunit of TFIIF under the control of T7 promoter (cat. #P1008); recombinant RAP30 protein is isolated from an E. coli strain that carries the coding sequence of human RAP30, the subunit of TFIIF under the control of T7 promoter (cat. #P1009); TFIIF is reconstituted by combining equimolar quantities of recombinant RAP30 and RAP74 (4).
TFIIF has been used for in vitro transcription assays, phosphorylation assays, protein-DNA, protein-RNA and protein-protein interactions assays (5-7).

SDS-PAGE with Coomassie Blue Staining