RPOL9RNA polymerase subunit 9
|SMART accession number:||SM00661|
|Interpro abstract (IPR001529):|
DNA-directed RNA polymerases EC 184.108.40.206 (also known as DNA-dependent RNA polymerases) are responsible for the polymerisation of ribonucleotides into a sequence complementary to the template DNA. In eukaryotes, there are three different forms of DNA-directed RNA polymerases transcribing different sets of genes. Most RNA polymerases are multimeric enzymes and are composed of a variable number of subunits. The core RNA polymerase complex consists of five subunits (two alpha, one beta, one beta-prime and one omega) and is sufficient for transcription elongation and termination but is unable to initiate transcription. Transcription initiation from promoter elements requires a sixth, dissociable subunit called a sigma factor, which reversibly associates with the core RNA polymerase complex to form a holoenzyme [(PUBMED:3052291)]. The core RNA polymerase complex forms a "crab claw"-like structure with an internal channel running along the full length [(PUBMED:10499798)]. The key functional sites of the enzyme, as defined by mutational and cross-linking analysis, are located on the inner wall of this channel.
RNA synthesis follows after the attachment of RNA polymerase to a specific site, the promoter, on the template DNA strand. The RNA synthesis process continues until a termination sequence is reached. The RNA product, which is synthesised in the 5' to 3'direction, is known as the primary transcript. Eukaryotic nuclei contain three distinct types of RNA polymerases that differ in the RNA they synthesise:
In archaebacteria, there is generally a single form of RNA polymerase which also consist of an oligomeric assemblage of 10 to 13 polypeptides. It has recently been shown [(PUBMED:8265347)], [(PUBMED:8417319)] that small subunits of about 15 kDa, found in polymerase types I and II, are highly conserved. These proteins contain a probable zinc finger in their N-terminal region and a C-terminal zinc ribbon domain (see IPR001222).
|GO process:||transcription, DNA-templated (GO:0006351)|
|GO function:||DNA-directed RNA polymerase activity (GO:0003899), DNA binding (GO:0003677)|
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