mRNA decapping enzyme 2 (Dcp2p; EC 3.6.1.62), nucleoside diphosphate linked moiety X))-type motif 20/Nudt20, is required for degradation of mRNAs, both in normal mRNA turnover, and in nonsense-mediated mRNA decay (NMD). Its catalytic subunit, and Dcp1p are the two components of the decapping enzyme complex. Decapping is a key step in both general and nonsense-mediated 5'->3' mRNA-decay pathways. Dcp2p contains an all-alpha helical N-terminal domain and a C-terminal domain which has the NUDIX fold. While decapping is not dependent on the N-terminus of Dcp2p, it does affect its efficiency. Dcp1p binds the N-terminal domain of Dcp2p stimulating the decapping activity of Dcp2p. Decapping permits the degradation of the transcript and is a site of numerous control inputs. It is responsible for nonsense-mediated decay as well as AU-rich element (ARE)-mediated decay. In addition, it may also play a role in the levels of mRNA. Enzymes belonging to the NUDIX hydrolase superfamily require a divalent cation, such as Mg2+ or Mn2+, for their activity and are recognized by a highly conserved 23-residue NUDIX motif (GX5EX7REUXEEXGU, where U = I, L or V).
Jiyao W et al.(2023). "The conserved domain database in 2023.",