Tetracycline is an antibiotic that blocks the a site on prokaryotic ribosomes, thus preventing translation. why doesn't it prevent translation in eukaryotic ribosomes?

Prokaryotic and eukaryotic ribosomes have similar structures but they are different. Prokaryotic ribosomes are composed of a 50s and 30s subunit, while Eukaryotic ribosomes are composed of a 60s and 40s subunit. Tetracycline binds to the a site of the 30s subunit of Prokaryotes but cannot bind efficiently to the same site in the 40s subunit of eukaryotic ribosomes due to the differences in structure and sequence.