POLR3A DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Largest and catalytic core component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Forms the polymerase active center together with the second largest subunit. A single-stranded DNA template strand of the promoter is positioned within the central active site cleft of Pol III. A bridging helix emanates from RPC1 and crosses the cleft near the catalytic site and is thought to promote translocation of Pol III 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. Plays a key role in sensing and limiting infection by intracellular bacteria and DNA viruses. Acts as nuclear and cytosolic DNA sensor involved in innate immune response. Can sense non-self dsDNA that serves as template for transcription into dsRNA. The non-self RNA polymerase III transcripts, such as Epstein-Barr virus-encoded RNAs (EBERs) induce type I interferon and NF- Kappa-B through the RIG-I pathway. Belongs to the RNA polymerase beta' chain family. Expressed in the brain, in the cortex and the white matter (at protein level). Note: This description may include information from UniProtKB.
Protein type: EC; Nucleotide Metabolism - purine; Nucleotide Metabolism - pyrimidine; Transcription initiation complex; Transferase
Chromosomal Location of human Ortholog: 10q22.3
Cellular Component:  cytosol; nucleoplasm; nucleus; RNA polymerase III complex
Molecular Function:  chromatin binding; DNA binding; DNA-directed 5'-3' RNA polymerase activity; metal ion binding; protein binding
Biological Process:  defense response to virus; DNA-templated transcription; innate immune response; positive regulation of interferon-beta production
Disease: Leukodystrophy, Hypomyelinating, 7, With Or Without Oligodontia And/or Hypogonadotropic Hypogonadism; Wiedemann-rautenstrauch Syndrome
Reference #:  O14802 (UniProtKB)
Alt. Names/Synonyms: ADDH; C160; DNA-directed RNA polymerase III largest subunit; DNA-directed RNA polymerase III subunit A; DNA-directed RNA polymerase III subunit RPC1; HLD7; hRPC155; POLR3A; polymerase (RNA) III (DNA directed) polypeptide A, 155kDa; polymerase (RNA) III subunit A; RNA polymerase III 155 kDa subunit; RNA polymerase III subunit A; RNA polymerase III subunit C1; RNA polymerase III subunit C160; RNA polymerase III subunit RPC155-D; RPC1; RPC155; WDRTS
Gene Symbols: POLR3A
Molecular weight: 155,642 Da
Basal Isoelectric point: 8.76  Predict pI for various phosphorylation states
Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology® Total Proteins
Select Structure to View Below


Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  Reactome  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  ENZYME  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene