| Primary Identifier | IPR027073 | Type | Family |
| Short Name | 5_3_exoribonuclease |
| description | This entry includes 5'-3'exoribonuclease type 1 and type 2. Putative viral exonucleases 059L and 012L, plant Xrn3 and Xrn4 also belong to this family. 5'-3'-exoribonucleases are enzymes that degrade RNA by removing terminal nucleotides from the 5' end. An exosome and a 5'-3'-exoribonuclease are important in the degradation of very unstable transcripts []. 5'-3'exoribonuclease type 1 (Xrn1, also known as kem1) occurs in animal and fungal lineages. In Saccharomyces cerevisiae, Xrn1 can be activated by Dcs1, a non-essential hydrolase that involved in mRNA decapping. The activation of Xrn1 by Dcs1 is important for respiration [].5'-3' exoribonuclease type 2 (Xrn2, also known as Rat1) occurs in animal, plant and fungal lineages. In Saccharomyces cerevisiae, Rat1 serves to terminateRNA polymerase II (RNAPII) molecules engaged in the production of uncapped RNA []. The concomitant loss of Xrn4 and ABH1/CBP80, a subunit of the mRNA cap binding complex, results in Arabidopsis plants manifesting myriad developmental defects [], suggesting that this enzyme is not only important for RNA processing. |
