obsolete endonuclease activity, active with either ribo- or deoxyribonucleic acids and producing 5'-phosphomonoesters https://github.com/geneontology/go-ontology/issues/24408 true molecular_function 5'-endonuclease activity OBSOLETE. Catalysis of the hydrolysis of ester linkages within nucleic acids by creating internal breaks to yield 5'-phosphomonoesters. GO:0016893 endoribonuclease activity, active with either ribo- or deoxyribonucleic acids and producing 5'-phosphomonoesters This term was obsoleted because it is an unnecessary grouping term.