Multifunctional cytochrome P450 orchestrates radical cleavage and non-radical cyclization in 5-oxaindolizidine biosynthesis
Penicilactam A (1), a fungal alkaloid featuring a rare 5-oxaindolizidine scaffold, has long eluded biosynthetic characterization despite recent advances in microbial genomics. Through retro-biosynthetic analysis of <i>Penicillium citrinum</i> HDN11-186, we identified the <i>pnlt</i> gene cluster governing its production. This pathway ultilizes a hybrid polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) system to assemble the prolinol-containing precursor scalusamide A (2). The multifunctional cytochrome P450 enzyme PnltC then orchestrates two mechanistically distinct reactions: radical-mediated C-C bond cleavage followed by iminium-driven cyclization. Combined structural and computational analyses unveil PnltC's unprecedented catalytic logic, merging radical oxidation with non-radical cyclization within a single active site, which challenges existing paradigms of P450 enzymology. Our findings expand the functional repertoire of oxygenases in natural products (NPs) biosynthesis, revealing nature's sophisticated strategies for constructing complex nitrogen heterocycles.
Authors
- Qian Che (ORCID: https://orcid.org/0000-0003-0610-1593)
- Ying-Han Chen (ORCID: https://orcid.org/0000-0002-6720-8610)
- Kaijin Zhang
- Wei Song (ORCID: https://orcid.org/0000-0001-6696-1208)
- Tianjiao Zhu (ORCID: https://orcid.org/0000-0003-4185-5593)
- Guojian Zhang (ORCID: https://orcid.org/0000-0002-4976-8083)
- Dehai Li (ORCID: https://orcid.org/0000-0002-7191-2002)
- Chuanteng Ma (ORCID: https://orcid.org/0000-0002-0262-8825)
- Zilin Ren (ORCID: https://orcid.org/0000-0002-3621-1024)
- Yankai Liu (ORCID: https://orcid.org/0000-0002-7292-1437)
- Yan Guan (ORCID: https://orcid.org/0000-0001-7653-5288)
- Yuting Liu (ORCID: https://orcid.org/0000-0002-5531-2437)
- Junyu Liu (ORCID: https://orcid.org/0000-0002-4293-1247)
- Jingxian Sun (ORCID: https://orcid.org/0000-0001-6878-7071)
Institutions
- Qingdao National Laboratory for Marine Science and Technology (CN)
- Ocean University of China (CN)
Publication Details
- Journal
- Chemical Science
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d4sc07174c
- Citations
- 2
- Primary Topic
- Microbial Metabolites in Food Biotechnology
- Type
- article
- Field-Weighted Citation Impact
- 2.24
Funders
- National Natural Science Foundation of China
- Ocean University of China
- China Scholarship Council
- Natural Science Foundation of Shandong Province
- Fundamental Research Funds for the Central Universities