This family consists of several scavenger mRNA decapping enzymes (DcpS) and is the N-terminal domain of these proteins. DcpS is a scavenger pyrophosphatase that hydrolyses the residual cap structure following 3' to 5' decay of an mRNA. 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.

1: The scavenger mRNA decapping enzyme DcpS is a member of the HIT family of pyrophosphatases. Liu H, Rodgers ND, Jiao X, Kiledjian M; EMBO J 2002;21:4699-4708. PMID:12198172