Endonuclease that catalyzes the cleavage of RNA on the 3' side of pyrimidine nucleotides. Acts on single-stranded and double-stranded RNA (By similarity). 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. Interacts with and forms tight 1:1 complexes with RNH1. Dimerization of two such complexes may occur. Interaction with RNH1 inhibits this protein (By similarity). Pancreas and other tissues and body fluids (indicating it may have other physiological functions besides its role in digestion). Belongs to the pancreatic ribonuclease family.