Abstract
Freda, Celia E. (University of Pennsylvania School of Medicine, Philadelphia), and Seymour S. Cohen. Nature of ribonucleic acid stimulated by streptomycin in the absence of protein synthesis. J. Bacteriol. 92:1680-1688. 1966.-The ribonucleic acid (RNA) synthesized in a thymineless, arginineless, uracil-less Escherichia coli strain 15 in the absence of arginine was characterized by sucrose density gradient centrifugation. About 60% of this RNA had sedimentation rates in the range between 4S and 16S, and the remainder was comprised of the 23S and 16S ribosomal components. On addition of streptomycin for 1 hr in the absence of the amino acid, there was an inhibition of synthesis of material of 4S to 16S, whereas 16S RNA was slightly stimulated. Between 1 and 3 hr after addition of the antibiotic, during the precipitous killing of the bacteria in the arginine-deficient culture, the synthesis of 16S ribosomal RNA was specifically and sharply stimulated.