Coupling and rearrangement reactions in the biosynthesis of bis-heterocyclic natural products

迫切需要新的抗生素和抗癌药物。产生新药物分子的一个重要途径是设计现有分子的生物合成途径，以创造具有改进药理特性的衍生物。细菌是这类药物分子和生物合成途径的丰富来源。生物合成基因在其基因组中的聚类使各种研究成为可能：容易识别新的基因簇，整个通路的异源表达，以及快速工程以产生新的生物合成衍生物。这项资助的重点是双杂环分子的生物合成途径，双杂环分子是一组结构上含有两个二聚的杂环单体的化合物。人们对导致这种分子产生的机制知之甚少。本课程的目的是表征两个重要的双杂环分子的生物合成途径和关键的生物合成酶。我的假设是，这两个分子来源于酶偶联和重排反应，这些反应融合和扭曲了经过充分研究的杂环单体，形成了不寻常的二聚分子骨架。这一假设将通过确定负责产生每个分子的基因簇和进行基因实验来测试单个生物合成基因的作用来验证。此外，我们将在生物化学和结构上表征每个途径中的关键酶。我们提出的生物合成研究具有重要意义，因为它们将提供必要的数据和材料，使研究能够生成这些药物分子结构相关衍生物的文库。该研究具有创新性，因为它侧重于杂环单体二聚化和重排以获得双杂环天然产物的酶基础，并将提供关于大自然如何构建这类分子的新知识。

There is an urgent need for new antibiotic and anticancer agents. One important route to generate new drug molecules is to engineer biosynthetic pathways to existing molecules to create derivatives with improved pharmacological properties. Bacteria are a rich source for such drug molecules and biosynthetic pathways. The clustering of biosynthetic genes in their genomes enables a variety of studies: facile identification of new gene clusters, heterologous expression of entire pathways, and rapid engineering to generate new biosynthetic derivatives. This grant is focused on the biosynthetic pathways to bis-heterocyclic molecules, a group of compounds containing two dimerized, heterocyclic monomers in their structures. Little is known about the mechanisms that lead to the production of such molecules. The objective of this program is to characterize the biosynthetic pathways and key biosynthetic enzymes to two important bis-heterocyclic molecules. My hypothesis is that these two molecules are derived from enzymatic coupling and rearrangement reactions that fuse and contort well-studied heterocyclic monomers into unusual, dimerized molecular skeletons. This hypothesis will be tested by identifying the gene cluster responsible for the production of each molecule and carrying out genetic experiments to test the roles of individual biosynthetic genes. Further, we will biochemically and structurally characterize key enzymes in each pathway. Our proposed biosynthetic studies are significant because they will provide the necessary data and materials to enable studies to generate libraries of structurally related derivatives of these drug molecules. The proposed research is innovative because it focuses on the enzymatic basis for the dimerization and rearrangement of heterocyclic monomers to give bis-heterocyclic natural products and will provide new knowledge about how nature constructs this class of molecules.