Polymerase (RNA) III (DNA Directed) Polypeptide B (POLR3B) Antibody – Rabbit Polyclonal

This gene encodes the second largest subunit of RNA polymerase III, the polymerase responsible for synthesizing transfer and small ribosomal RNAs in eukaryotes. The largest subunit and the encoded protein form the catalytic center of RNA polymerase III. Mutations in this gene are a cause of hypomyelinating leukodystrophy. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Dec 2011]

POLR3B: DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. Second largest core component of RNA polymerase III which synthesizes small RNAs, such as 5S rRNA and tRNAs. Proposed to contribute to the polymerase catalytic activity and forms the polymerase active center together with the largest subunit. Pol III is composed of mobile elements and RPC2 is part of the core element with the central large cleft and probably a clamp element that moves to open and close the cleft. 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 POLR3B are the cause of leukodystrophy, hypomyelinating, type 8, with or without oligodontia and/or hypogonadotropic hypogonadism (HLD8). An autosomal recessive neurodegenerative disorder characterized by early childhood onset of cerebellar ataxia and mild intellectual disabilities associated with diffuse hypomyelination apparent on brain MRI. Variable features include oligodontia and/or hypogonadotropic hypogonadism. Belongs to the RNA polymerase beta chain family.

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

Chromosomal Location of Human Ortholog: 12q23.3

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

Molecular Function: DNA binding; ribonucleoside binding; metal ion binding

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

Disease: Leukodystrophy, Hypomyelinating, 7, With Or Without Oligodontia And/or Hypogonadotropic Hypogonadism; Leukodystrophy, Hypomyelinating, 8, With Or Without Oligodontia And/or Hypogonadotropic Hypogonadism