Tetracyclines bind to the 30S subunit of microbial ribosomes. They prevent protein synthesis by blocking the attachment of the charged amino acyl-tRNA to the A site on the ribosome. They prevent the introduction of new amino acids to the nascent peptide chain.

Uses

Tetracycline has a bacteriostatic activity against aerobic and anaerobic bacterial species. It remains useful in the management of infections by certain intracellular bacterial pathogens such as syphilis, leptospirosis and Lyme disease. It is also active against eukaryotic parasites such as malaria and balantidiasis. Certain infections including anthrax, plague and brucellosis are also susceptible to tetracyclines.