Abstract
Lavanduquinocin (LDQ) is a potent neuroprotective carbazole alkaloid from Streptomyces species that features a rare cyclic monoterpene/cyclolavandulyl moiety attached to the tricyclic carbazole nucleus. We elucidated the biosynthetic logic of LDQ by enzymatically reconstituting the total biosynthetic pathway and identified the genes required for generating the cyclolavandulyl moiety in LDQ based on mutagenetic analysis, including a cyclolavandulyl diphosphate synthase gene ldqA and a squalene synthase-like aromatic prenyltransferase gene ldqG. LdqG is homologous to carbazole prenyltransferases, NzsG and CqsB4, discovered from the biosynthetic pathways of two bacterial carbazoles, neocarazostatin and carquinostatin. Based on analysis of the sequences and modeled protein structures, further in vitro and in vivo site-directed mutagenetic analyses led to identification of two residue sites, F53 and C57 in NzsG vs I54 and A58 in LdqG, which play crucial roles in governing the prenyl donor specificities toward cyclolavandulyl, dimethylallyl, and geranyl diphosphates. By applying this knowledge in strain engineering, prenyl donor delivery was rationally switched to produce the desired prenylated carbazoles. The study provides an opportunity to rationally manipulate the prenylation modification to carbazole alkaloids, which could influence the biological activities by increasing the affinity for membranes as well as the interactions with cellular targets.
Original language | English |
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Pages (from-to) | 123-133 |
Number of pages | 11 |
Journal | ACS Chemical Biology |
Volume | 18 |
Issue number | 1 |
Early online date | 6 Jan 2023 |
DOIs | |
Publication status | Published - 20 Jan 2023 |
Bibliographical note
Funding Information:This work received financial support from the National Natural Science Foundation of China (Nos. 32070070, 31929001, and 22137006), the National Key R&D Program of China (2019YFC0312501), and the Innovative research team of high-level local universities in Shanghai. H.D. thanks the Royal Society─NSFC International Exchange Grant (IEC\NSFC\211349).