Non-ribosomal peptides

These peptides are synthesized using a modular enzyme complex. Nonribosomal peptides are confined primarily to unicellular organisms, plants, and fungi. There is a common core structure to all of these complexes, and they can contain many different modules to perform chemical manipulations on the evolving product. In general, these peptides are cyclic (often with highly-complex cyclic structures), although linear nonribosomal peptides are common.