DCPS (gene)
Scavenger mRNA-decapping enzyme DcpS is a protein that in humans is encoded by the DCPS gene.
The scavenger mRNA decapping enzymes include Dcp2 and DcpS. DcpS is a scavenger pyrophosphatase that hydrolyses the residual cap structure following 3' to 5' mRNA degradation. DcpS uses cap dinucleotides or capped oligonucleotides as substrates to release mGMP, while Dcp2 uses capped mRNA as a substrate in order to hydrolyse the cap to release mGDP. The association of DcpS with 3' to 5' exonuclease exosome components suggests that these two activities are linked and there is a coupled exonucleolytic decay-dependent decapping pathway. The family contains a histidine triad sequence in its C-terminal domain, with three histidines separated by hydrophobic residues. The central histidine within the DcpS HIT motif is critical for decapping activity and defines the HIT motif as a new mRNA decapping domain, making DcpS the first member of the HIT family of proteins with a defined biological function.
