Streptomycin has a three-dimensional structure similar to that of the 3’ end of a charged tRNA. It stops translation of bacterial and eukaryotic mRNAs by binding at the ribosomal A site and acting as an analog of charged tRNA.
Streptomycin exclusively blocks eukaryotic translation by binding to the 60S subunit and inhibiting peptidyl transferase activity, much like chloramphenicol does to bacterial peptidyl transferase.
Streptomycin binds to the 50S (large) subunit in the tunnel from which the newly synthesized polypeptide emerges, blocking the passage of the polypeptide out of the ribosome.
Streptomycin inhibits bacterial translation by interfering with binding of N-formylmethionine tRNA to the ribosome.