Nuclease S1, Aspergillus oryzae is a Zn2+-dependent, single-strand-specific nuclease. Nuclease S1, Aspergillus oryzae hydrolyzes phosphodiester bonds in single-stranded DNA and RNA, producing mononucleotides and oligonucleotides with 5'-phosphate termini. Nuclease S1, Aspergillus oryzae also exhibits 3'-nucleotidase activity, which hydrolyzes the 3'-monophosphate group of nucleotides.