RNA Polymerase II-p14.5 subunit, hRPB9

• Species: Human
• Expression Host: E. coli
• Tag: His-tag
• Purity: 90%
• Molecular Weight: 16.6 kDa.
• Gene Accession Number: NM_006233.

Purification and Quality Control

The His-tag recombinant protein is purified by affinity chromatography in combination with FPLC columns. The purified RNA Polymerase II-p14.5 subunit is greater than 90% homogeneous based on SDS-PAGE analysis.

Unit Definition (Activity)

1 unit equals 1 nanogram of purified protein. 1 unit is sufficient for a gel mobility shift assay in a 20 µl reaction; 100 units are sufficient for protein-protein interaction assays.

Applications

hRPB9 can be applied in invitro transcription assays, in vitro elongation assays and protein-protein interaction assays.

Formulation and Storage

The protein is in 20mM Tris-HCl pH7.9,100mM NaCl, 0.2mM EDTA, 1mM DTT and 20% glycerol. Stored at -70°C before use. Avoid repeated freeze thaw cycles.

Synonym

POLR2I; hRPB14.5; RPB9; RNA polymerase II p14.5 subunit; RNA polymerase II subunit B9;DNA-directed RNA polymerase II subunit I; DNA-directed RNA polymerase II 14.5 kDa polypeptide; RNA polymerase II 14.5 kDa subunit

PROTEIN Sequence

MEPDGTYEPG FVGIRFCQEC NNMLYPKEDK ENRILLYACR NCDYQQEADN SCIYVNKITH
EVDELTQIIA DVSQDPTLPR TEDHPCQKCG HKEAVFFQSH SARAEDAMRL YYVCTAPHCG
HRWTE

Background

hRPB9 is a subunit unique to RNA polymerase II, although it has sequence homologues in RNA polymerases I and III (1). The gene for Rpb9 is not essential for yeast cell viability (2), but is essential in Drosophila (3). hRPB9 has roles in both transcription initiation and trascription elongation. In the initiation reaction it is necessary for accurate start site selection (4). In the elongation reaction, RPB9, along with TFIIS facilitates the conversion of an arrest-competent conformation to a read-through competent conformation (5). RNA polymerase II lacking the RPB9 subunit uses alternate transcription initiation sites in vitro and in vivo and is unable to respond to the transcription elongation factor TFIIS in vitro (6). A role in the modulation of initiation and elongation is consistent with the localization of RPB9 in the three-dimensional structure of yeast RNA polymerase II. RPB9 is located at the tip of the so-called "jaws" of the enzyme, which is thought to function by clamping the DNA dowstream of the active site (7). RPB9 comprises two zinc ribbon domains joined by a conserved linker region. The C-terminal zinc ribbon is similar in sequence to that found in TFIIS (8).

Image of SDS-PAGE / Western-blot