Engineering lanthipeptides by introducing a large variety of RiPP modifications to obtain new-to-nature bioactive peptides.

Natural bioactive peptide discovery is a challenging and time-consuming process. However, advances in synthetic biology are providing promising new avenues in peptide engineering that allow for the design and production of a large variety of new-to-nature peptides with enhanced or new bioactivities, using known peptides as templates. Lanthipeptides are ribosomally synthesized and post-translationally modified peptides (RiPPs). The modularity of posttranslational modification enzymes and ribosomal biosynthesis inherent to lanthipeptides, enable their engineering and screening in a high-throughput manner. The field of RiPPs research is rapidly evolving, with many novel post-translational modifications (PTMs) and their associated modification enzymes being identified and characterized. The modularity presented by these diverse and promiscuous modification enzymes has made them promising tools for further in vivo engineering of lanthipeptides, allowing for the diversification of their structures and activities. In this review, we explore the diverse modifications occurring in RiPPs and discuss the potential applications and feasibility of combining various modification enzymes for lanthipeptide engineering. We highlight the prospect of lanthipeptide- and RiPP engineering to produce and screen novel peptides, including mimics of potent non-ribosomally produced antimicrobial peptides (NRPs) such as daptomycin, vancomycin and teixobactin, which offer high therapeutic potential.