Yukito Oota

Synthesis of ribonucleic acids in microbial cells. I. Ribosomal ribonucleic acid synthesis in growing bacterial cells.

A procedure of separating nucleic acids and nucleoproteins from bacterial extracts by DEAE-column chromatography has been described. The method allows to separate s-RNA, “DNA”, several classes of ribosomes and their possible precursors. The study of incorporation of isotopic precursors into nucleic acids in growing cells of Escherichia coli and Bacillus cereus has suggested that the ribosomal RNA is first formed on DNA and finally built up to complete ribosomal particles via sequential intermediate steps. The intermediates including a “DNA-RNA complex” are accumulated when protein synthesis is inhibited by 8-azaguanine or chloramphenicol. The DNA-RNA complex is sensitive either to DNAase or to RNAase. Judged from the results of a degradation experiment with DNAase, the molecular size of the RNA component of the complex is fairly small.