Enables hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in cyclic amides. Involved in pyrimidine nucleobase catabolic process. Located in nucleus. Expressed in
hyp7 syncytium. Human ortholog(s) of this gene implicated in Ritscher-Schinzel syndrome; dihydropyrimidinase deficiency; and purine-pyrimidine metabolic disorder. Is an ortholog of human DPYS (dihydropyrimidinase).