PHOSPHONIC ACID BIOSYNTHETIC PATHWAYS

在之前的资助期间，我们的酶学和合成化学研究补充了遗传和生物化学方面的努力，以了解天然产物磷酸盐的生物合成逻辑。该计划项目团队已经取得了重大进展，开发了检测新的磷酸盐生物合成基因簇的有效方法，并非常详细地了解了导致商业上重要的磷酸盐(如膦硫蛋白和磷霉素)的生物合成途径。随着遗传和生化研究变得更加高效，发现了一个新的瓶颈，涉及到低效的纯化策略，从而减缓了新发现的基因簇的产物的结构阐明。这一分项目中拟议的部分研究将侧重于开发有效的方法来提纯和阐明这些新化合物的结构。此外，过去赠款期间的基因组测序工作发现，在不同的生物体中，相同的天然产物是通过非常不同的生物合成路线产生的。我们将研究这些收敛进化的例子。最后，许多天然产物磷酸盐以短肽的形式产生，以促进多肽在目标生物体中的摄取。然而，对于某些化合物，小的非核糖体多肽合成酶(NRPS)簇负责形成肽键，许多含膦酸多肽以不同的方式组装，通常是未知的。我们将尝试就未来可能的工程努力对这一非常重要的方面提供更多的见解。

In the previous grant period, our enzymology and synthetic chemistry studies complemented the genetic and biochemical efforts towards understanding the biosynthetic logic of natural product phosphonates. The program project team has made significant progress, developing effective methods to detect new phosphonate biosynthetic gene clusters and understanding in great detail the biosynthetic pathways leading towards commercially important phosphonates such as phosphinothricin and fosfomycin. As the genetic and biochemical studies became more efficient, a new bottleneck was idenyified that involves inefficient purification strategies and hence slow-down of structure elucidation of the products of newly discovered gene clusters. Part of the proposed studies in this subproject will focus on the development of efficient methods for purification and structural elucidation of those new compounds. In addition, the genome sequencing efforts of the past grant period identified cases in which the same natural product is made in different organisms by very different biosynthetic routes. We will investigate these examples of convergent evolution. Finally, many natural product phosphonates are produced as short peptides to promote uptake by peptide permeases in the target organisms. Whereas for some compounds small non-ribosomal pepfide synthetase (NRPS) clusters are responsible for peptide bond formation, many phosphonate containing peptides are assembled In different, often unidentified ways. We will attempt to provide more insight into this very important aspect with respect to possible future engineering efforts.