Ribonuclease T1 Digestion of Deaminated Polyribonucleotides and Its Applicability for Nucleotide Sequence Analysis in Polyribonucleotides*

Abstract

High-molecular-weight baker''s yeast RNA and Torula yeast sRNA were deaminated with a NaNO2 -acetic acid system. A slight degradation of polynucleotide chains could not be avoided in the process of deamination. Deaminated RNAs were digested with RNase T1 and the products were analyzed. The products of deamination were successfully fractionated by DEAE-cellulose column chromatography with a LiAc-LiC1 system. The fractionation depended mainly on the nucleotide units. With enzyme/ substrate ratio below 1/1000 (w/w), RNase T1 split practically exclusively phosphodiester bonds of inosinic acid in deaminated RNA (ca 20 nucleotide units). The probable application of the RNase T1 digestion of deaminated polyribonucleotides to nucleotide sequence analysis is discussed.