Adenylate-Rich Oligonucleotides from Ribosomal RNA of Animal Cells

Abstract

A mixture of oligonucleotides has been prepared from animal cell ribosomal RNA by treatment with pancreatic and T1 ribonucleases. Tetra-, penta-, and hexanucleotides from this digest have been fractionated and analyzed. In addition to the expected components having the nucleotide sequence (Ap)nCp, (Ap)nUp, and (Ap)nGp, others contain sugar- and base-methylated residues. Some of the oligonucleotides are found only in 18 S RNA and others only in 28 S RNA. The patterns are distinctive and can be used as biochemical markers for distinguishing between the two RNA species. Evidence is presented which suggests that ribosomal RNA is heterogeneous with respect to some of these components.