Judge, Jury, and Executioner: DXO Functions as a Decapping Enzyme and Exoribonuclease in Pre-mRNA Quality Control

Abstract

In this issue of Molecular Cell, Jiao et al. (2013) describe the mammalian enzyme DXO, which has pyrophosphohydrolase, decapping, and 5'-3' exoribonuclease activity and functions as an important checkpoint in cotranscriptional capping of RNA polymerase II (Pol II) pre-mRNA transcripts.