GST-RPB3

In human, RPB3 is encoded by the POLR2C gene (1). This gene encodes the third largest subunit of RNA polymerase II.  The product of this gene contains a cysteine rich region and exists as a heterodimer with another polymerase subunit, POLR2J. These two subunits form a core subassembly unit of the polymerase.  

DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Pol II is the central component of the basal RNA polymerase II transcription machinery. RPB3 is part of the core element with the central large cleft and the clamp element that moves to open and close the cleft.  In the pol II complex, RPB3 interacts with RPB5 and the RPB3–RPB5 interaction is intensified in the presence of three subunits, RPB7, RPB8 and RPB11. Besides, RPB3 also interacts with RPB1-5, 7, 10-12 (2).

RPB3 is involved in tissue-specific transcription and muscle differentiation via interaction with the myogenic factor Myogenin (3). RPB3 also interact with IGFBP3 (4).

GSt tagged Recombinant human RPB3 is isolated from an E coli strain that carries the coding sequence of human POLR2C under the control of a T7 promoter.
RPB3 has been applied in protein-protein interactions assays.
Protein is greater than 95% homogeneous based on SDS-PAGE analysis.
1 unit equals 1 nanogram of purified protein. 100 units are sufficient for a protein-protein interaction assay.
Variable exists in different lots.
1x dilution buffer A: 20 mM Tris-Cl (pH 8.0), 20% Glycerol, 100 mM KCl, 1 mM DTT and 0.2 mM EDTA

References:

1. http://www.ncbi.nlm.nih.gov/nuccore/89276761
2. Acker J, de Graff M, et al., (1997). J Biol Chem. 272 (27): 16815–21.

3. Corbi, N., PASSANANTI, C., et al., (2002) FASEB J.  10.10963.

4. Oufattole,M., Lin,S.W., (2006) Endocrinology 147 (5), 2138-2146.

5. http://en.wikipedia.org/wiki/RNA_polymerase_II.