RNase T1

RNase T1

a nuclease that endonucleolytically cleaves ribonucleic acids at the 3'-5' link of a guanosine 3'-phosphate residue, producing oligonucleotides terminating in this nucleotide; a transferase (endonuclease) in the first (cyclizing) step, a phosphodiesterase on the second (hydrolyzing) step.
Synonym(s): guanyloribonuclease, RNase N1