The lantibiotics are a unique class of bacterium-derived peptide antibiotics, all of which contain the rare amino acid lanthionine, as well as a number of other nonprotein amino acids. Unlike most other peptide antibiotics, lantibiotics are produced on the ribosome as a prepeptide, and a series of post-translational modifications converts this precursor into the biologically active peptide. A complex set of gene products involved in lantibiotic biosynthesis have been identified, including the genes for specific amino acid modifications, as well as other ancillary biosynthetic functions. In the future, it should be possible to use some of these enzymes to engineer novel, non-protein amino acids into other proteins of biotechnological interest and importance.