Ribonuclease T1 (Rnase T1), widely utilized in biochemical research, is an endonuclease targeting single-stranded RNA. It cleaves the phosphodiester bond between 3'-guanosine residues and adjacent nucleoside 5'-OH groups, thereby producing 3'-GMP terminal oligonucleotides, and forms nucleoside 2', 3'-cyclic phosphoric acid intermediates in the process [1].