Cyclic peptide production using a macrocyclase with enhanced substrate promiscuity and relaxed recognition determinants

Macrocyclic peptides have promising therapeutic potential but the scaling up of their chemical synthesis is challenging. The cyanobactin macrocyclase PatG_mac is an efficient tool for production but is limited to substrates containing 6–11 amino acids and at least one thiazoline or proline. Here we report a new cyanobactin macrocyclase that can cyclize longer peptide substrates and those not containing proline/thiazoline and thus allows exploring a wider chemical diversity.