Nucleotide Sequence of 5S Ribosomal RNA from Lingula anatina1

Abstract

By chromatography on columns of DEAE-Sephadex A-50 and Sephadex G-100, and electrophoresis on polyacrylamide gel, 5S rRNA was purified from a low-molecular-weight RNA fraction extracted from the total tissues of Lingula anatina. Complete digests of the 5S rRNA with RNase T₁ [EC 3.1.4.8] and pancreatic RNase [EC 3.1.4.22] were sequenced by conventional column chromatography procedures. The nucleotide sequence of this RNA was determined mainly by a chemical method for sequencing the RNA 3′ end-labeled with P (1), with the complement of the oligonucleotide catalog obtained by the complete RNase digestions of the RNA. By comparing the sequences of several invertebrate, vertebrate, and Chiorella 5S rRNAs, a phylogenic tree of the rRNAs was constructed and the time of divergence of Lingula was estimated.