Competitive Binding of Streptomycin and Magnesium with Escherichia coli Ribosomes

SEVERAL laboratories have presented evidence that streptomycin inhibits protein synthesis of sensitive bacteria 1–4 . Studies with cell free systems have clearly shown that the 30 S sub-unit of the ribosomes derived from streptomycin-sensitive cells is the site of action of this antibiotic 5–8 . It has also been shown that one to two molecules of streptomycin bound to one ribosome particle suffice to exert an inhibitory effect on polypeptide synthesis 9,10 .