Synthetic microcin C analogs targeting different aminoacyl-tRNA synthetases.

Microcin C (McC) is a potent antibacterial agent produced by some strains of Escherichia coli. McC consists of a ribosomally synthesized heptapeptide with a modified AMP attached through a phosphoramidate linkage to the alpha-carboxyl group of the terminal aspartate. McC is a Trojan horse inhibitor: it is actively taken inside sensitive cells and processed there, and the product of processing, a nonhydrolyzable aspartyl-adenylate, inhibits translation by preventing aminoacylation of tRNA(Asp) by aspartyl-tRNA synthetase (AspRS).