RNA Polymerase II-Carboxy terminal Domain (1586-1951)

• Species: Human
• Expression Host: E. coli
• Tag: His-tag
• Purity: 95%
• Molecular Weight: 42.2 kDa.
• Gene Accession Number: NM_000937.

The carboxy-terminal repeat domain (CTD) of the largest subunit of RNA pol II contains tandem repeats of a heptapeptide sequence Tyr-Ser-Pro-Thr-Ser-Pro-Ser which is highly conserved among eukaryotic organisms (1). There are two forms of RNA pol II in vivo, designated IIO, which is extensively phosphorylated at the CTD, and IIA, which is not phosphorylated. The IIA form preferentially enters the pre-initiation complex (PIC), whereas IIO is found in the elongating complex (2-3). The kinase activity of TFIIH can mediate CTD phosphorylation (4), although other kinases, including Cdc2 (5), Ctk1 (6), the Srb10-Srb11 kinase-cyclin pair (7), and P-TEFb (8), have also been implicated in CTD phosphorylation. A phosphatase responsible for the dephosphorylation of the CTD has also been identified (9). CTD phosphatase activity is regulated by TFIIB and TFIIF (10). The CTD has also been implicated in pre-mRNA processing, most likely functioning as a platform for the recruitment and assembly of factors involved in pre-mRNA processing (11). Molecular weight is calculated by the protein sequence. SDS-PAGE migtation is around 66 kDa.

Purification and Quality Control

Recombinant His tagged CTD is isolated from an E. coli strain that carries the coding sequence of human RNA pol II carboxy-terminal domain under the control of a T7 promoter.

Unit Definition (Activity)

1 unit equals 1 nanogram of purified protein. 20 units are sufficient for reconstituted transcription assay and 100 units are sufficient for a protein-protein interaction assay.

Applications

CTD has been applied in in vitro transcription assays, splicing assays and protein-protein interactions assays. 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.

Synonym

hRPB220; hsRPB1; MGC75453; POLR2; POLRA;RPB1; RPBh1; RpIILS; RPO2; RPOL2; POLR2A

Target Gene Sequence

SPSYSPTSPA YEPRSPGGYT PQSPSYSPTS PSYSPTSPSY SPTSPNYSPT SPSYSPTSPS YSPTSPSYSP TSPSYSPTSP SYSPTSPSYS PTSPSYSPTS PSYSPTSPSY SPTSPSYSPT SPSYSPTSPS YSPTSPSYSP TSPSYSPTSP SYSPTSPNYS PTSPNYTPTS PSYSPTSPSY SPTSPNYTPT SPNYSPTSPS YSPTSPSYSP TSPSYSPSSP RYTPQSPTYT PSSPSYSPSS PSYSPTSPKY TPTSPSYSPS SPEYTPTSPK YSPTSPKYSP TSPKYSPTSP TYSPTTPKYS PTSPTYSPTS PVYTPTSPKY SPTSPTYSPT SPKYSPTSPT YSPTSPKGST YSPTSPGYSP TSPTYSLTSP AISPDDSDEE N

Background

The human p75 protein, similar to p52, is a non-TAF transcription coactivator that mediates activator-dependent transcription by RNA polymerase II in vitro through most tested activators (1, 2). Although p75 and p52 are derived from alternatively splicing of a single gene and share most coding sequence, they reveal different functions in several aspects. In addition to functioning as a transcription coactivator, p75 has been shown to be involved in growth of epithelial cells as a lens epithelial cell-derived growth factor (LEDGF), and in pathogenesis of atopic dermatitis as an autoantigen (3-5).

SDS-PAGE with Coomassie Blue staining