Cyclic peptides are important bioactive compounds and drugs, synthesised by enzymatic side-chain macrocyclization of ribosomal peptides, which rarely involves histidine residues. Here, the authors report the discovery and biosynthesis of tricyclic lanthipeptide noursin, constrained by a tri amino acid labionin crosslink and histidine-to-butyrine crosslink, which is important for copper binding of noursin.
- Yuqing Li
- Yeying Ma
- Huan Wang