PA48009, a lanthionine-containing peptide antibiotic was isolated from the culture broth of Streptoverticillium griseoverticillatum PA-48009, and identified as duramycin. Determination of the structure using both Edman degradations and 2D NMR spectroscopy showed the need to revise the structure of duramycin given in literature. Duramycin (PA48009) was different from lanthiopeptin (Ro 09-0198, cinnamycin) only by a Lys/Arg exchange at position 2.