5'-3' exoribonuclease 2

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5'-3' exoribonuclease 2
Symbol XRN2
External IDs OMIM608851 MGI894687 HomoloGene6927 GeneCards: XRN2 Gene
EC number 3.1.13.-
Species Human Mouse
Entrez 22803 24128
Ensembl ENSG00000088930 ENSMUSG00000027433
UniProt Q9H0D6 Q9DBR1
RefSeq (mRNA) NM_012255 NM_011917
RefSeq (protein) NP_036387 NP_036047
Location (UCSC) Chr 20:
21.28 – 21.37 Mb
Chr 2:
147.01 – 147.08 Mb
PubMed search [1] [2]

5'-3' Exoribonuclease 2 (XRN2) also known as Dhm1-like protein is an exoribonuclease enzyme that in humans is encoded by the XRN2 gene.[1]

The human gene encoding XRN2 shares similarity with the mouse Dhm1 and the yeast's Dhp1 (Schizosaccharomyces pombe) or RAT1 (Saccharomyces) genes. The yeast gene is involved in homologous recombination and RNA metabolism, such as RNA synthesis and RNA trafficking and termination.[2] Complementation studies show that Dhm1 has a similar function in mouse as Dhp1.


Human XRN2 is involved in the torpedo model of transcription termination.[3]

The C. elegans homologue, XRN-2, is involved in the degradation of certain mature miRNAs and their dislodging from miRISC miRNAs.[4]

In yeast, the Rat1 protein has been shown to also be involved in the torpedo transcription termination model. When a polyadenylation site has been detected on the nascent RNA and cleaved by the RNA polymerase II, the Rtt103 factor recruits Rat1 and attaches it to free end. The exonuclease activity of Rat1 degrades the RNA strand and halts transcriptions upon catching up to the polymerase.[2]


  1. ^ Zhang M, Yu L, Xin Y, Hu P, Fu Q, Yu C, Zhao S (July 1999). "Cloning and mapping of the XRN2 gene to human chromosome 20p11.1-p11.2". Genomics 59 (2): 252–4. doi:10.1006/geno.1999.5866. PMID 10409438. 
  2. ^ a b David Tollervey (November 2004). "Termination by torpedo". Nature 432: 456–457. doi:10.1038/432456a. 
  3. ^ West S, Gromak N, Proudfoot NJ (November 2004). "Human 5' --> 3' exonuclease Xrn2 promotes transcription termination at co-transcriptional cleavage sites". Nature 432 (7016): 522–5. doi:10.1038/nature03035. PMID 15565158. 
  4. ^ Chatterjee S, Grosshans H (September 2009). "Active turnover modulates mature microRNA activity in Caenorhabditis elegans". Nature 461 (7263): 546–9. doi:10.1038/nature08349. PMID 19734881. 

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