Graduate Division of Nutritional and Environmental Sciences, University of Shizuoka, Suruga-ku, Shizuoka, Japan.
Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara, Japan.
Biosci Biotechnol Biochem. 2021 Nov 24;85(12):2404-2409. doi: 10.1093/bbb/zbab165.
Tropane alkaloids, including clinically important hyoscyamine and scopolamine, are produced in the roots of medicinal plant species, such as Atropa belladonna, from the Solanaceae family. Recent molecular and genomic approaches have advanced our understanding of the metabolic enzymes involved in tropane alkaloid biosynthesis. A noncanonical type III polyketide synthase, pyrrolidine ketide synthase (PYKS) catalyzes a two-step decarboxylative reaction, which involves imine-ketide condensation indispensable to tropane skeleton construction. In this study, we generated pyks mutant A. belladonna hairy roots via CRISPR/Cas9-mediated genome editing and analyzed the metabolic consequences of the loss of PYKS activity on tropane alkaloids, providing insights into a crucial role of the scaffold-forming reaction in the biosynthetic pathway.
托烷生物碱，包括临床上重要的莨菪碱和东莨菪碱，是在茄科药用植物如颠茄的根部产生的。最近的分子和基因组方法提高了我们对参与托烷生物碱生物合成的代谢酶的理解。一种非典型的 III 型聚酮合酶，吡咯烷酮酮合酶 (PYKS) 催化两步脱羧反应，其中涉及到不可缺少的亚胺-酮烯缩合反应，这对托烷骨架的构建至关重要。在这项研究中，我们通过 CRISPR/Cas9 介导的基因组编辑生成了突变的颠茄发根，并分析了 PYKS 活性丧失对托烷生物碱的代谢后果，为支架形成反应在生物合成途径中的关键作用提供了见解。
