Mupirocin

As a member of tRNA synthetase inhibitor antibiotics, it acts on the binding site of isoleucyl-tRNA synthetase and isoleucine in bacterial cells, inhibiting the biosynthesis of isoleucine and depleting intracellular tRNA, thus halting the synthesis of RNA and protein in susceptible bacteria. It exhibits potent antibacterial activity mainly against aerobic Gram-positive cocci, especially *Staphylococcus aureus*, *Staphylococcus epidermidis* and *Streptococcus pyogenes* associated with skin infections, and is also effective against drug-resistant *Staphylococcus aureus*. Susceptible Gram-negative bacteria include *Haemophilus influenzae* and *Neisseria gonorrhoeae*. It has extremely low affinity for mammalian isoleucyl-tRNA synthetase, resulting in very low toxicity to humans.