InterPro domain: IPR006886

DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. RNA polymerase III (Pol III) is a complex consisting of 17 subunits, which synthesizes small RNAs, such as 5S rRNA and tRNAs. Pol III is essential for efficient transcription from both the type 2 VAI and type 3 U6 RNA polymerase III promoters and plays a key role in sensing and limiting infection by intracellular bacteria and DNA viruses, being involved in innate immune response, as it induces type I interferon and NF-Kappa-B through the RIG-I pathway [ 1 ]. Subunit C5 is a specific peripheric component of RNA polymerase III complex. This subunit forms a subcomplex with RPC4 which is close to the active centre allowing the formation of the open promoter complex and facilitates termination and reinitiation. RPC5 mutations are associated with impaired type I INF and increased susceptibility to viral infections [ 2 ].

1. RNA polymerase III detects cytosolic DNA and induces type I interferons through the RIG-I pathway. Cell 138, 576-91
2. A mutation in POLR3E impairs antiviral immune response and RNA polymerase III. Proc. Natl. Acad. Sci. U.S.A. 117, 22113-22121