XRN2
Description
The XRN2 (5'-3' exoribonuclease 2) is a protein-coding gene located on chromosome 20.
XRN2, also known as DHM1-like protein, is an exoribonuclease enzyme encoded by the XRN2 gene in humans. It is homologous to the mouse Dhm1 and yeast Dhp1/Rat1 genes. XRN2 is involved in transcription termination, particularly the 'torpedo model' where it degrades the 3' fragment of RNA after cleavage at the polyadenylation site. In C. elegans, the homologue XRN-2 degrades mature miRNAs. XRN2's function is similar to that of the yeast Rat1 protein, which is recruited to the free end of the nascent RNA by the Rtt103 factor and degrades the RNA strand, halting transcription.
XRN2 possesses 5'-to-3' exoribonuclease activity. It is involved in the termination of transcription by RNA polymerase II. During this process, the RNA is cleaved at the polyadenylation site, producing a 5' fragment (which is processed into mature mRNA) and a 3' fragment that remains attached to the polymerase. XRN2 degrades this 3' fragment, which promotes transcription termination. It binds to RNA polymerase II transcription termination R-loops formed by G-rich pause sites.
XRN2 is also known as -.
