Key Laboratory of Saline-alkali Vegetation Ecology Restoration (Northeast Forestry University), Ministry of Education, Harbin 150040, China.
College of Life Science, Northeast Forestry University, Harbin 150040, China.
Sci Adv. 2024 Nov 29;10(48):eads3596. doi: 10.1126/sciadv.ads3596.
Berberine is an effective antimicrobial and antidiabetic alkaloid, primarily extracted from divergent botanical lineages, specifically (Ranunculales, early-diverging eudicot) and (Sapindales, core eudicot). In comparison with its known pathway in species, its biosynthesis in species remains elusive. Using chromosome-level genome assembly, coexpression matrix, and biochemical assays, we identified six key steps in berberine biosynthesis from , including methylation, hydroxylation, and berberine bridge formation. Notably, we discovered a specific class of -methyltransferases (NOMT) responsible for -methylation. Structural analysis and mutagenesis of PaNOMT9 revealed its unique substrate-binding conformation. In addition, unlike the classical FAD-dependent berberine bridge formation in Ranunculales, uses a NAD(P)H-dependent monooxygenase (PaCYP71BG29) for berberine bridge formation, originating from the neofunctionalization of tryptamine 5-hydroxylase. Together, these findings reveal the convergence of berberine biosynthesis between and and signify the role of the convergent evolution in plant specialized metabolisms.
小檗碱是一种有效的抗菌和抗糖尿病生物碱，主要从不同的植物谱系中提取，特别是 （毛茛目，早期分化的真双子叶植物）和 （芸香目，核心真双子叶植物）。与已知的 物种中的途径相比，其在 物种中的生物合成仍然难以捉摸。使用染色体水平的基因组组装、共表达矩阵和生化分析，我们从 中鉴定出小檗碱生物合成的六个关键步骤，包括甲基化、羟基化和小檗碱桥的形成。值得注意的是，我们发现了一类特定的 -甲基转移酶（NOMT）负责 -甲基化。PaNOMT9 的结构分析和突变显示了其独特的底物结合构象。此外，与毛茛目经典的 FAD 依赖性小檗碱桥形成不同， 使用 NAD(P)H 依赖性单加氧酶（PaCYP71BG29）进行小檗碱桥形成，源自色胺 5-羟化酶的新功能化。总之，这些发现揭示了 和 之间小檗碱生物合成的趋同，并表明趋同进化在植物特殊代谢物中的作用。
