Discoveries about the structure of Streptococcus pneumoniae may help doctors resume penicillin use against this and other resistant strains. An international research effort has revealed the role of a MurM, a key Streptococcus protein, in producing structures in the bacterium's cell walls that enhance penicillin resistance. MurM permits formation within the cell wall of dipeptide bridges, which in higher quantities can prevent the usual destructive action of penicillin. Researchers have now replicated in the lab the mechanism by which MurM aids dipeptide-bridge production; this may reveal ways to target MurM directly and eliminate penicillin resistance. It's also hoped that this discovery will provide clues to attacking methicillin-resistant Staphylococcus aureus—another bacterium that relies on cell-wall dipeptide bridges for enhanced resistance.

http://Eurekalert.org/. "Research could put penicillin back in battle against antibiotic resistant bugs that kill millions." 2008. http://www.eurekalert.org/pub_releases/2008-03/uow-rcp031208.php (13 Mar. 2008).

Lloyd, A. J., Gilbey, A. M., et al. (2008). Characterization of tRNA-dependent peptide bond formation by MurM in the synthesis of streptococcus pneumoniae peptidoglycan. J Biol Chem 283(10), 6402.