ID:RPB1_MOUSE DESCRIPTION: RecName: Full=DNA-directed RNA polymerase II subunit RPB1; Short=RNA polymerase II subunit B1; EC=184.108.40.206; AltName: Full=DNA-directed RNA polymerase II subunit A; AltName: Full=DNA-directed RNA polymerase III largest subunit; FUNCTION: 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 (By similarity). CATALYTIC ACTIVITY: Nucleoside triphosphate + RNA(n) = diphosphate + RNA(n+1). SUBUNIT: 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, 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. Hyperphosphorylated form on tandem 7 residues repeats specifically interacts with SETD2 (By similarity). Interacts with PAF1. Interacts (via C-terminus) with FTSJD2 and CTDSP1 (By similarity). Interacts with MYO1C. Interacts (via C- terminus) with SCAF8. Interacts via the phosphorylated C-terminal domain with WDR82 and with SETD1A and SETD1B only in the presence of WDR82 (By similarity). Interacts with ATF7IP (By similarity). When phosphorylated at 'Ser-5', interacts with MEN1; the unphosphorylated form, or phosphorylated at 'Ser-2' does not interact. Interacts with DDX5 (By similarity). SUBCELLULAR LOCATION: Nucleus. PTM: The tandem 7 residues repeats in the C-terminal domain (CTD) can be highly phosphorylated. The phosphorylation activates Pol II. Phosphorylation occurs mainly at residues 'Ser-2' and 'Ser-5' of the heptapepdtide repeat and is mediated, at least, by CDK7 and CDK9. CDK7 phosphorylation of POLR2A associated with DNA promotes transcription initiation by triggering dissociation from DNA. Phosphorylation also takes place at 'Ser-7' of the heptapepdtide repeat, which is required for efficient transcription of snRNA genes and processing of the transcripts. The phosphorylation state is believed to result from the balanced action of site-specific CTD kinases and phosphatase, and a 'CTD code' that specifies the position of Pol II within the transcription cycle has been proposed (By similarity). PTM: Dephosphorylated by the protein phosphatase CTDSP1 (By similarity). PTM: Following UV treatment, the elongating form of RNA polymerase II (RNA pol IIo) is ubiquitinated UV damage sites without leading to degradation: ubiquitination is facilitated by KIAA1530/UVSSA and promotes RNA pol IIo backtracking to allow access to the nucleotide excision repair machinery (By similarity.) Ubiquitinated by WWP2 leading to proteasomal degradation. PTM: Methylated at Arg-1810 by CARM1. Methylation occurs only when the CTD is hypophosphorylated, and phosphorylation at Ser-1805 and Ser-1808 prevent methylation (in vitro). It is assumed that methylation occurs prior to phosphorylation and transcription initiation. CTD methylation may facilitate the expression of select RNAs (By similarity). MISCELLANEOUS: The binding of ribonucleoside triphosphate to the RNA polymerase II transcribing complex probably involves a two- step mechanism. The initial binding seems to occur at the entry (E) site and involves a magnesium ion temporarily coordinated by three conserved aspartate residues of the two largest RNA Pol II subunits. The ribonucleoside triphosphate is transferred by a rotation to the nucleotide addition (A) site for pairing with the template DNA. The catalytic A site involves three conserved aspartate residues of the RNA Pol II largest subunit which permanently coordinate a second magnesium ion. SIMILARITY: Belongs to the RNA polymerase beta' chain family.
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
SCOP Domains: 82714 - Multidrug efflux transporter AcrB TolC docking domain; DN and DC subdomains 64484 - beta and beta-prime subunits of DNA dependent RNA-polymerase
ModBase Predicted Comparative 3D Structure on P08775
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.