Recently, at the invitation bythe journal Natural Product Reports, an international high impactjournal of the Royal Society of Chemistry, the microbial intelligent design and synthesis innovation team of the Biotechnology Research Institute and the National Technical Research Center of Finland jointly published a review article entitled "engineering thebiosynthesis of fungal nonribosomal peptides", which comprehensively summarized the main progress, bottleneck problems and priority areas in this field in the past decade.
Nonribosomal peptide (NRP) secondary metabolites synthesized by fungi are important sources of medical and agricultural drugs, such as penicillin, cephalosporin, echinocandin and PF1022A, which play an important role in antibacterial and insecticidal applications. Compared with bacteria, the engineering of fungal NRP biosynthesis pathway is still in its infancy. The reason is not only limited by the lack of understanding of the biosynthesis mechanism, but also limited by the difficulty of manipulation of giant eukaryotic multi-module NRPsynthase genes.
In this paper, four major strategies to engineer NRP biosynthesis pathway in fungi were systematically discussed: 1) indigenous activation and heterologous expression; 2) precursor directed biosynthesis and mutasynthesis; 3) combinatorial biosynthesis and enzyme engineering; 4) in vitro biochemical and chemoenzymatic synthesis. The engineering of four major typesof NRP products, cyclooligomericdepsipeptides, cyclic peptide, NRPs produced by hybrid megasynthase systems and NRPS-like synthasewere summarized. At present, the most in-depth research in the field of fungal NRPS biosynthesis mechanism and engineering is cyclooligomericdepsipeptides synthesized by biocontrol fungi, such as beauvericin,enniatin, PF1022and bassianolide. The engineering of these NRPSs to synthesize new skeletons and new active products showed great potential, and also provides a paradigm for the study of other types of fungal NRPS. However, limited by the technical bottleneck of heterologous expression of most fungal giant NRPS (more than hundreds or even thousands of kDa), the transformation of NRPS with more than three modules has rarely been reported. For example, the biosynthetic engineering of antifungal drugs such as echinocandin is still limited to the precursor oriented biosynthesis and knockout of the tailoring enzyme. The paper further analyzed the gap between the theory and the existing methods, deeply discussed the limitations of the current field and the priority development areas, and provided constructive suggestions for the upgrading of future engineering strategies.
Dr. LiwenZhang and Dr. Chen Wang are the co-first authors, and ProfessorYuquanXu and Professor IstvánMolnár are the corresponding authors. This research is supported by the National Natural Science Foundation of China and the innovation project of the Chinese Academy of Agricultural Sciences. (correspondent:Yan Cui)
Figure note: four major methods for engineering thebiosynthesis of fungal nonribosomal peptides
Link：https://pubs.rsc.org/en/content/articlelanding/2022/np/d2np00036a |