Properties of Ribosomes and Ribosomal RNAs Synthesized by Escherichia coli, Grown in the Presence of Ethionine

Abstract
Analysis of 16S rRNA synthesized in E. coli D10 (met-) incubated in a medium containing ethionine in place of methionine shows that it lacks most and probably all methyl groups present in normal 16S rRNA but possesses the same 3''-OH and 5''-phosphate terminal sequences as the latter. The 23S rRNA formed in ethionine-treated cells also contains normal terminal sequences. The 5S rRNA of normal and ethionine-treated E. coli D10 are identical. Methylation of ribosomal precursor RNA species is not necessary for their maturation to products with normal chain lengths and does not influence the conformation of 16S rRNA.