Your browser is unable to support new features implemented in HTML5 and CSS3 to render this site as intended. Your experience may suffer from functionality degradation but the site should remain usable. We strongly recommend the latest version of Google Chrome, OS X Safari or Mozilla Firefox. As Safari is bundled with OS X, if you are unable to upgrade to a newer version of OS X, we recommend using an open source browser. Dismiss message
IPR012162 is a Polyribonucleotide nucleotidyltransferase.
<p>The eukaryotic exosome and the prokaryotic degradosome are important protein complexes involved in RNA processing and maintaining appropriate RNA levels within the cell [[cite:PUB00033243]]. Both of these complexes contain exoribonucleases (exoRNases) which degrade RNA from the 3' end. The hydrolytic exoRNases produce nucleoside monophosphates, while the phosphorolytic exoRNases add orthophosphate at the cleaved bond to produce nucleoside monophosphates.</p> <p>This entry represents polyribonucleotide nucleotidyltransferase ([ec:2.7.7.8]), also known as polynucleotide phosphorylase (PNPase), found in bacterial and eukaryotic organelle degradosomes. This enzyme can process single-stranded RNA, but is stalled by double-stranded structures such as stem-loops. Structural studies show that PNPase is a trimeric multidomain protein with a central channel [[cite:PUB00024411]]. Each subunit contains duplicated RNase PH-like domains which, though structurally homologous, are thought to be functionally distinct. The first domain is more divergent in sequence than than the second domain and is thought to be involved in the flexible binding of RNA substrate and the formation of the trimer channel structure. The second domain is thought to contain the catalytic site and show exoRNase activity. The catalytic mechanism of the enzyme is not yet known but it seems likely that single-stranded RNA would be threaded through the channel to be processed by the three active sites within the trimer, which would thus be restricted to a single substrate molecule per trimer. PNPase activity would thus be tightly regulated by secondary structural elements within the RNA [[cite:PUB00035567]].</p>
This description is obtained from EB-eye REST.
GO predictions are based solely on the InterPro-to-GO mappings published by EMBL-EBI, which are in turn based on the mapping of predicted domains to the InterPro dataset. The InterPro-to-GO mapping was last updated on , while the GO metadata was last updated on .
| GO term | Namespace | Name | Definition | Relationships |
|---|---|---|---|---|
| Molecular function | RNA binding | Interacting selectively and non-covalently with an RNA molecule or a portion thereof. | ||
| Molecular function | Polyribonucleotide nucleotidyltransferase activity | Catalysis of the reaction: RNA(n+1) + phosphate <=> RNA(n) + a nucleoside diphosphate. | ||
| Biological process | MRNA catabolic process | The chemical reactions and pathways resulting in the breakdown of mRNA, messenger RNA, which is responsible for carrying the coded genetic 'message', transcribed from DNA, to sites of protein assembly at the ribosomes. |
| Transcript | Name | Description | Predicted domains | Domain count |
|---|---|---|---|---|
| – | PREDICTED: probable polyribonucleotide nucleotidyltransferase 1, chloroplastic-like [Cicer arietinum] gi|502107284|ref|XP_004493216.1| | 23 | ||
| – | PREDICTED: probable polyribonucleotide nucleotidyltransferase 1, chloroplastic-like [Cicer arietinum] gi|502107284|ref|XP_004493216.1| | 36 | ||
| – | PREDICTED: polyribonucleotide nucleotidyltransferase 2, mitochondrial-like [Cicer arietinum] gi|502090489|ref|XP_004489245.1| | 33 | ||
| – | Polyribonucleotide nucleotidyltransferase; TAIR: AT3G03710.1 polyribonucleotide nucleotidyltransferase; Swiss-Prot: sp|Q69LE7|PNP1_ORYSJ Probable polyribonucleotide nucleotidyltransferase 1, chloroplastic; TrEMBL-Plants: tr|G7L1J6|G7L1J6_MEDTR Polyribonucleotide nucleotidyltransferase; Found in the gene: LotjaGi1g1v0648200 | 36 | ||
| – | Polyribonucleotide nucleotidyltransferase; TAIR: AT5G14580.1 polyribonucleotide nucleotidyltransferase; Swiss-Prot: sp|Q9S7G6|PNP2_ARATH Polyribonucleotide nucleotidyltransferase 2, mitochondrial; TrEMBL-Plants: tr|V7C0V9|V7C0V9_PHAVU Uncharacterized protein; Found in the gene: LotjaGi2g1v0243700 | 32 | ||
| – | Polyribonucleotide nucleotidyltransferase; TAIR: AT5G14580.1 polyribonucleotide nucleotidyltransferase; Swiss-Prot: sp|Q9S7G6|PNP2_ARATH Polyribonucleotide nucleotidyltransferase 2, mitochondrial; TrEMBL-Plants: tr|V7C0V9|V7C0V9_PHAVU Uncharacterized protein; Found in the gene: LotjaGi2g1v0243700 | 35 |
A list of co-occurring predicted domains within the L. japonicus gene space:
| Predicted domain | Source | Observations | Saturation (%) |
|---|---|---|---|
| mobidb-lite | MobiDBLite | 1 | 16.67 |