Studies on ribonucleases in Takadiastase

Abstract
This enzyme specifically hydrolyzes the secondary phosphate ester bonds of guanosine-3[image]-phosphate (G-3[image]-P) of yeast ribonucleic acid (RNA). The reaction proceeds in 2 stages: (1) transphosphorylative cleavage to form guanosine-2[image],3[image]-cyclic phosphate (G-2[image],3[image]-P) or G-2[image],3[image]-P-termlnal oligonucleo-tide(s); (2) hydrolysis to free guanosine-3[image]-phosphate(G-3[image]-P) or G-3[image]-P-terminal oligonucleotide(s), respectively by use of phosphomonoesterase the freed mononucleotide, namely G-3[image]-P, is determined as 40% of total G-3[image]-P residues in RNA. This finding indicates that there are a considerable number of two or more adjacent G-3''-P residues in the RNA molecule.