Discovery of Natural Product Chemical Diversity and Novel Biosynthetic Enzymes

 描述(由申请人提供)：由于对现有药物的抗病能力不断增强，以及新药线索的管道不断减少，我们产生化学多样性的需求变得越来越重要。挖掘化学多样性的最佳来源仍然是天然产品。在后基因组学时代，必须开发利用大量基因组信息的新方法，以及合成和化学生物学中的强大工具，并将其应用于挖掘自然化学多样性。我们认为，许多已经鉴定和培养的微生物含有比迄今开发的更多的生物合成潜力，而对已知的生物合成酶的操纵将带来比目前更多的多样性。因此，充分捕捉生物合成潜力 自然界为结构多样化和药物铅识别提供了巨大的希望。除了发现具有新结构和生物活性的天然产物外， 确定导致结构复杂性的新酶也同样重要。与初级代谢中的酶相比，生物合成酶催化更多样化和更复杂的转化，从而导致天然产品中令人眼花缭乱的结构特征。因此，需要完全了解从天然产物途径中发现的新酶的编程规则和酶学。更深入地了解酶的蛋白质序列-活性关系也可以从基因组序列中更合理地预测天然产品的结构，进而可以进一步加速基因组挖掘工作，以开发新的天然产品。在这项提案中，我们将制定策略来挖掘丝状真菌中编码的化学多样性，发现导致结构复杂性的酶，并在适用的情况下将酶工程成有用的生物催化剂。我们将1)开发和应用新的工具来探索基于系统发育和生物生态位的不同丝状真菌物种的遗传编码化学空间；2)开发和验证目标导向挖掘方法，将基于基因组学的挖掘与临床相关的生物活性联系起来；3)对真菌生物合成途径中的酶进行生化表征，以建立序列-活性关系。将研究PKS的编程规则以及氧化酶的编程规则；以及4)对从生物合成途径中发现的蛋白质进行结构引导和进化工程，使其成为有用的生物催化剂。

 DESCRIPTION (provided by applicant): Due to increasing disease resistance to existing drugs and a dwindling pipeline of new drug leads, our need to generate chemical diversity is becoming ever more important. The best source to mine chemical diversity remains to be from natural products. In the post-genomics era, new approaches using the vast genomic information, as well as powerful tools in synthetic and chemical biology must be developed and applied towards the mining of natural chemical diversity. We believe that many of the microorganisms already identified and cultured contain far more biosynthetic potential than what has been tapped so far, and the manipulation of the known biosynthetic enzymes will lead to even more diversity than currently accessible. Therefore, capturing the full biosynthetic potential of Nature offers immense promise towards structural diversification and drug lead identification. In addition to discovering the natural products that have new structures and biological activities, it is equally important to identify new enzymes that responsible for generating the structural complexities. Compared to enzymes found in primary metabolism, biosynthetic enzymes catalyze significantly more diverse and complex transformations that lead to the dazzling structural features seen in the natural products. Therefore, complete understanding of the programming rules and enzymology of new enzymes discovered from the natural product pathways is needed. Deeper insight into the protein sequence-activity relationships of the enzymes can also enable more rational prediction of natural product structures from genome sequences, and can in turn further accelerate the genome mining efforts towards new natural products. In this proposal we will develop strategies to mine the chemical diversity encoded in filamentous fungi, discover the enzymes that give rise to the structural complexity and engineer enzymes into useful biocatalysts where applicable. We will 1) develop and apply new tools to explore genetically encoded chemical space from different filamentous fungi species based on phylogeny and bioecological niche; 2) develop and validate a target-guided mining approach that connects genomics-based mining to clinically relevant biological activity; 3) perform biochemical characterization of enzymes in fungal biosynthetic pathways to establish sequence- activity relationships. Programming rule of PKS will be studied, as well as those of oxidative enzymes; and 4) perform structure-guided and evolutionary engineering of proteins discovered from biosynthetic pathways towards becoming useful biocatalysts.