RPB1 Antibody – Rabbit Polyclonal

This gene encodes the largest subunit of RNA polymerase II, the polymerase responsible for synthesizing messenger RNA in eukaryotes. The product of this gene contains a carboxy terminal domain composed of heptapeptide repeats that are essential for polymerase activity. These repeats contain serine and threonine residues that are phosphorylated in actively transcribing RNA polymerase. In addition, this subunit, in combination with several other polymerase subunits, forms the DNA binding domain of the polymerase, a groove in which the DNA template is transcribed into RNA. [provided by RefSeq, Jul 2008]

POLR2A: DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic component of RNA polymerase II which synthesizes mRNA precursors and many functional non-coding RNAs. Forms the polymerase active center together with the second largest subunit. Pol II is the central component of the basal RNA polymerase II transcription machinery. It is composed of mobile elements that move relative to each other. RPB1 is part of the core element with the central large cleft, the clamp element that moves to open and close the cleft and the jaws that are thought to grab the incoming DNA template. At the start of transcription, a single stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol II. A bridging helix emanates from RPB1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol II by acting as a ratchet that moves the RNA-DNA hybrid through the active site by switching from straight to bent conformations at each step of nucleotide addition. During transcription elongation, Pol II moves on the template as the transcript elongates. Elongation is influenced by the phosphorylation status of the C-terminal domain (CTD) of Pol II largest subunit (RPB1), which serves as a platform for assembly of factors that regulate transcription initiation, elongation, termination and mRNA processing. Acts as a RNA- dependent RNA polymerase when associated with small delta antigen of Hepatitis delta virus, acting both as a replicate and transcriptase for the viral RNA circular genome. Component of the RNA polymerase II (Pol II) complex consisting of 12 subunits. The phosphorylated C-terminal domain interacts with FNBP3 and SYNCRIP. Interacts with SAFB/SAFB1. Interacts with CCNL1 and MYO1C. Interacts with CCNL2 and SFRS19. Component of a complex which is at least composed of HTATSF1/Tat-SF1, the P-TEFb complex components CDK9 and CCNT1, RNA polymerase II, SUPT5H, and NCL/nucleolin. Interacts with PAF1. Interacts (via C-terminus) with FTSJD2, CTDSP1 and SCAF8. Interacts via the phosphorylated C-terminal domain with WDR82 and with SETD1A and SETD1B only in the presence of WDR82. Interacts with ATF7IP. When phosphorylated at 'Ser-5', interacts with MEN1; the unphosphorylated form, or phosphorylated at 'Ser-2' does not interact. Interacts with DDX5. Belongs to the RNA polymerase beta' chain family.

Protein type: Nucleotide Metabolism - purine; Transcription initiation complex; EC 2.7.7.6; Transferase; EC 2.7.7.48; Nucleotide Metabolism - pyrimidine

Chromosomal Location of Human Ortholog: 17p13.1

Cellular Component: nucleoplasm; nucleolus; DNA-directed RNA polymerase II, core complex; nucleus

Molecular Function: protein binding; RNA-directed RNA polymerase activity; DNA binding; DNA-directed RNA polymerase activity; ubiquitin protein ligase binding; metal ion binding

Biological Process: transcription from RNA polymerase II promoter; transcription initiation from RNA polymerase II promoter; viral reproduction; somatic stem cell maintenance; positive regulation of viral transcription; RNA splicing; DNA repair; positive regulation of RNA splicing; nuclear mRNA splicing, via spliceosome; mRNA capping; regulation of transcription, DNA-dependent; nucleotide-excision repair; transcription-coupled nucleotide-excision repair; RNA elongation from RNA polymerase II promoter; gene expression