DNA-Directed RNA Polymerase III Subunit RPC1 (POLR3A) Human Recombinant Protein

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. Defects in POLR3A are the cause of leukodystrophy hypomyelinating type 7 with or without oligodontia and/or hypogonadotropic hypogonadism (HLD7). An autosomal recessive neurodegenerative disorder characterized by childhood onset of progressive motor decline manifest as spasticity, ataxia, tremor, and cerebellar signs, as well as mild cognitive regression. Other features may include hypodontia or oligodontia and hypogonadotropic hypogonadism. There is considerable inter- and intrafamilial variability. Belongs to the RNA polymerase beta' chain family.

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

Chromosomal Location of Human Ortholog: 10q22.3

Cellular Component: cytosol; DNA-directed RNA polymerase III complex; membrane; nucleoplasm

Molecular Function: chromatin binding; DNA binding; DNA-directed RNA polymerase activity; metal ion binding

Biological Process: defense response to virus; gene expression; innate immune response; positive regulation of interferon type I production; positive regulation of interferon-beta production; RNA elongation from RNA polymerase III promoter; termination of RNA polymerase III transcription; transcription from RNA polymerase III promoter; transcription, DNA-dependent

Disease: Leukodystrophy, Hypomyelinating, 7, With Or Without Oligodontia And/or Hypogonadotropic Hypogonadism