Figure 1.

General biosynthetic pathway leading to RiPP production, from the gene cluster to the mature active compound. The ribosomally synthesized precursor can be only cleaved by a protease (green) and exported by an ABC transporter (brown) as an unmodified peptide. For RiPP biosynthesis, the core peptide is fused to a leader peptide (gray) that contributes to the action of the posttranslational modification enzymes (blue). Cleavage of the leader and export of the RiPP are both generally ensured by a peptidase-containing ATP-binding transporter (PCAT) that accomplishes the two functions.