Josamycin is a macrolide antibiotic from Streptomyces narbonensis. The drug has antimicrobial activity against a wide spectrum of pathogens and used for the treatment of bacterial infections. Josamycin targets the protein synthesis machinery in the bacterial cytoplasm to inhibit protein synthesis and prevent bacterial growth. Josamycin enters through the bacterial cell membrane through a transporter and binds to the bacterial ribosome. The bacterial ribosome consists of two subunits: the 50s and the 30s subunit. Josamycin binds to the 50s subunit and prevents translocation of the tRNA along the A, P and E sites of the ribosome. Translocation of amino acids from the acceptor site (A site) to the donor site (P site) is prevented and as a result, protein synthesis is halted. The bacterial cells are unable to generate proteins necessary for growth and duplication, therefore, growth of the bacteria is inhibited. This action is mainly bacteriostatic, but can also be bactericidal at high concentrations. Macrolides tend to accumulate within leukocytes, and are therefore actually transported into the site of infection. Side effects from taking josamycin may include abdominal pain, nausea, vomiting, diarrhea and skin rashes.

Josamycin Pathway References