Ribonuclease (RNase) is a type of nuclease that catalyzes the degradation of RNA into smaller components. RNases can be classified intoexoribonucleases, when they cleave terminal nucleotides, such as RNase T or RNase D, andendoribonucleases, when they cleave nucleotides inside the RNA chain, such as RNase A orRNase H.