Enzymes of the chalcone synthase superfamily from plants and microorganisms

来自植物和微生物的查尔酮合酶超家族的酶

• 批准号: 262038-2008
• 负责人: Suh, DaeYeon
• 金额: $ 2.04万
• 依托单位: University of Regina
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=498032
• 关键词: Enzymes; chalcone; synthase; superfamily; plants

Plant secondary metabolites such as flavonoids (UV protection), isoflavonoids (Rhizobium nodulation), anthocyanins (floral color), and antimicrobial phytoalexins are all derived from polyketides synthesized by the members of chalcone synthase (CHS) superfamily. These enzymes are small (homodimer of ~42 kDa subunits), yet remarkably complex enzymes and catalyze multiple-step reactions at a single active site. Thus, they provide a good model for other multi-component polyketide synthases, which are responsible for biosynthesis of a variety of useful natural products including antibiotics, immunosuppressants and anticancer agents. Recent structural and mechanistic studies on CHS and related enzymes have yielded insights into enzyme mechanisms and the molecular basis of biosynthetic versatility of the CHS superfamily. Stilbene synthase, another representative member of the superfamily, has attracted much attention in transgenic crop development due to the antifungal activity and a number of beneficial health effects of stilbenes. The proposed mechanistic study on the STS-catalyzed cyclization reaction using unexplored bioorganic chemical approaches will provide much needed insight that should prove valuable in the manipulation of polyketide biosynthesis through metabolic engineering. Already underway are studies on CHS-like enzymes from a cyanobacterium, a nitrogen-fixing bacterium, a moss, and a primitive plant, horsetail. Results obtained from these studies will lead to a better understanding of the evolution of enzyme family and metabolic pathway in plants and microorganisms. Finally, the moss homologue of anther-specific CHSs may provide insights into the poorly understood process of plant male fertility.

植物次生代谢物，如类黄酮（紫外线防护）、异黄酮（根瘤菌结瘤）、花青素（花色）和抗菌植物抗毒素，均源自查尔酮合酶（CHS）超家族成员合成的聚酮化合物。这些酶虽小（约 42 kDa 亚基的同二聚体），但酶却非常复杂，可在单个活性位点催化多步反应。因此，它们为其他多组分聚酮合酶提供了良好的模型，这些多组分聚酮合酶负责多种有用的天然产物的生物合成，包括抗生素、免疫抑制剂和抗癌剂。最近对 CHS 和相关酶的结构和机制研究深入了解了 CHS 超家族的酶机制和生物合成多功能性的分子基础。二苯乙烯合酶是该超家族的另一个代表性成员，由于二苯乙烯的抗真菌活性和许多有益健康的作用，在转基因作物开发中引起了广泛关注。所提出的使用未探索的生物有机化学方法对 STS 催化环化反应的机理研究将提供急需的见解，这在通过代谢工程操纵聚酮化合物生物合成中应该具有价值。对蓝藻、固氮细菌、苔藓和原始植物木贼中的类 CHS 酶的研究已经在进行中。这些研究获得的结果将有助于更好地了解植物和微生物中酶家族和代谢途径的进化。最后，花药特异性 CHS 的苔藓同源物可能为人们对植物雄性育性过程知之甚少的过程提供见解。