RR01, RNase R, Ribonuclease R Ribonuclease R (RNase R), derived from the E. coli RNR superfamily, is a magnesium ion dependent 3 '- 5' ribonuclease that can gradually cut RNA into dinucleotides and trinucleotides from the 3 '- 5' direction. RNase R can digest almost all linear RNA, but it is