part of RNA endonuclease activity producing 5'-phosphomonoesters, hydrolytic mechanism miRNA-mediated gene silencing by mRNA destabilization endoribonuclease activity, cleaving miRNA-paired mRNA Catalysis of the endonucleolytic cleavage of the mRNA in a double-stranded RNA molecule formed by the base pairing of an mRNA with an miRNA. GO:0090624 2015-01-21T16:28:52Z molecular_function tb