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

Abstract

Tetracycline, an inhibitor of cell-free protein synthesis, effected the dissociation of Escherichia coli 100S ribosomes to 70S particles in vivo and in vitro, but was not observed to mediate the further degradation of these particles. The antibiotic was bound by both 50S (Svedberg) and 30S subunits of 70S ribosomes and also by E. coli soluble RNA (sRNA), polyuridylic acid (poly U), and polyadenylic acid (poly A). The binding to ribosomal subunits was higher at 5 X 104 M Mg++ than at 10-2 M Mg++. The binding to polynucleotide chains was highest when Mg++ was not added to the reaction mixture.