Endonuclease that catalyzes the cleavage of RNA on the 3' side of pyrimidine nucleotides. Compared to RNASE1 it has lost activity towards dsRNA. an [RNA] containing cytidine + H2O = an [RNA]-3'-cytidine-3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA]. an [RNA] containing uridine + H2O = an [RNA]-3'-uridine-3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA]. Monomer. Belongs to the pancreatic ribonuclease family.