Antibacterial drug bacitracin

Antibacterial drugs that affect cell wall synthesis include two large femilies,the penicillins and cephalosporins, and two individual drugs, bacitracin and vancomycin. 

Bacitracin contains a cyclic peptide as part of a complex structure of 12 amino acid residues (if one considers the thiazole ring as cysteine derived). Bacitracin-treated bacterial cultures accumulate precursor peptidoglycan chains, as do the penicillins. However, the mechanism is very different. Its prevention of lysine inclusion into the murein structure is probably of lesser significance. Later demonstration show that drug binding to the membrane-bound bactoprene phosphate and the metal ions (Zn2+ are particularly involved) is more likely to be important to the antibacterial mechanism, namely, inhibition of dephosphorylation of the phospholipid carrier. 

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