THE DEPENDENCE OF NUCLEIC ACID SYNTHESES ON THE PRESENCE OF AMINO ACIDS IN ESCHERICHIA COLI

Abstract

Under conditions of amino acid deficiency ribonucleic acid (RNA) synthesis and, to a smaller extent, deoxyribonucleic acid (DNA) synthesis were inhibited in E. coli. Nucleic acid precursors are not accumulated. Chloromycetin permitted nucleic acid synthesis without protein synthesis. The nucleic acid made under these conditions had the same basic composition as that found in uninhibited cells. Chloromycetin did not permit RNA synthesis in amino acid deficient mutant bacteria. Addition of traces of amino acids permitted extensive RNA synthesis. More RNA was made in the presence of chloromycetin than without chloromycetin when small quantities of amino acids were available. It is concluded that in uninhibited E. coli, formation of nucleic acids from nucleotides is coordinated with formation of protein from amino acids, with resultant formation of nucleoproteins. In the presence of chloromycetin peptide bond formation is inhibited, but the amino acids must still be present to permit nucleic acid synthesis.