5'-3' exoribonuclease type 2 (IPR017151)

Short name: Xrn2/3/4

Overlapping homologous superfamilies


Family relationships


5'-3'-exoribonucleases are enzymes that degrade RNA by removing terminal nucleotides from the 5' end. Hydrolytic exoribonucleases, to which this entry belongs, produce nucleotide monosphosphates. An exosome and a 5'-3'-exoribonuclease are important in the degradation of very unstable transcripts [PMID: 18481995].

This entry includes 5'-3'exoribonuclease type 2 (Xrn2, also known as Rat1), which occurs in animal, plant and fungal lineages. They act as post-transcriptional gene silencing (PTGS) suppressors [PMID: 17993620]. In Saccharomyces cerevisiae, Rat1 serves to terminate RNA polymerase II (RNAPII) molecules engaged in the production of uncapped RNA [PMID: 20188675]. This entry also includes plant Xrn3 and Xrn4.

GO terms

Biological Process

GO:0006139 nucleobase-containing compound metabolic process

Molecular Function

GO:0004534 5'-3' exoribonuclease activity

Cellular Component

GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.