Structure of microcin C51, a new antibiotic with a broad spectrum of activity

Abstract
The structure of microcin C51, a new antibiotic produced by E. coli, has been determined. This antibiotic was shown to be a 1.18 kDa nucleotide peptide. It consists of a heptapeptide with formylmethionine as the N‐terminus and a C‐terminal asparagine linked with nebularin‐5′‐monophosphate through the three‐methylene bridge. The OH‐group of threonine is substituted. The peptide chain of microcin C51 synthesized on ribosomes is the longest among the known biologically active nucleotide peptides.