| Description | 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. | | 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 | | Synonym | hRPB220; hsRPB1; MGC75453; POLR2; POLRA;RPB1; RPBh1; RpIILS; RPO2; RPOL2; POLR2A | | Storage and Formulation | 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. | | 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. | | Application | CTD has been applied in in vitro transcription assays, splicing assays and protein-protein interactions assays. For research use only. | | Reference | 1. Lu, H., et al., (1991) Proc. Natl. Acad. Sci. USA 88, 10004-10008
2. Dahmus, M.E. (1994) Prog. Nucleic Acid Res. Mol. Biol. 48, 143-179
3. O’Brian, T., et al., (1994) Nature 370, 75-77
4. Feaver, W. J., et al.,(1991) Cell 67, 1223-1230
5. Cisek, L.J., et al., (1989) Nature 339, 679-684
6. Lee, J. M., et al., (1991) Gene Expr. 1, 149-167
7. Liao, S. M., et al., (1995) Nature 374, 193-196
8. Marshall, N. F., et. al., (1996) J. Biol. Chem. 271, 27176-27183
9. Chambers, R.S., et al., (1994) J. Biol. Chem. 269, 26243-26248
10. Chambers, R. S., et al., (1995) J. Biol. Chem. 270, 14962-14969
11. McCracken, S., et al., (1997) Nature 385, 357-361 | | SDS-PAGE with Coomassie Blue staining |  |
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