Tetracycline Inhibition of Cell-Free Protein Synthesis II. Effect of the Binding of Tetracycline to the Components of the System

Abstract

Day , L. E. (Chas. Pfizer & Co., Inc., Groton, Conn.). Tetracycline inhibition of cell-free protein synthesis. II. Effect of the binding of tetracycline to the components of the system. J. Bacteriol. 92: 197–203. 1966.—When tetracycline, an inhibitor of cell-free protein synthesis, was preincubated with each component of the Escherichia coli cell-free system, i.e., ribosomes, soluble ribonucleic acid (sRNA), polyuridylic acid (poly U), and S-100 (supernatant enzymes), only the ribosomal-bound antibiotic was inhibitory to the cell-free assay. Experiments designed to further localize the site of inhibition to either the 50 S (Svedberg) or the 30 S ribosomal subunit were not conclusive. Tritiated tetracycline (7-H 3 -tetracycline) was bound to isolated 50 S ribosomes, and these were recombined with 30 S subunits to form 70 S ribosomes. When these ribosomes were dissociated and the subunits reisolated, the antibiotic was found with both the 50 S and the 30 S particles. The same results were observed when the tetracycline was initially bound to the 30 S subunit.