Evolution of plant secondary metabolism: The promiscuity of short chain dehydrogenases/reductases involved in tropinone reduction

植物次生代谢的进化：参与托品酮还原的短链脱氢酶/还原酶的混杂

• 批准号: 166283962
• 负责人: Privatdozent Dr. Wolfgang Brandt
• 金额: --
• 依托单位: Abteilung Natur- und Wirkstoffchemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/166283962?language=en
• 关键词: Evolution; plant; secondary; metabolism; promiscuity

The goal of the project is to study short-chain dehydrogenases/reductases (SDR) for catalytic capacities and evolvability and to gain information on their native function. Tropinone reduction is a step in tropane alkaloid biosynthesis performed by SDR. A tropinone reductase from tropane alkaloid-forming Cochlearia officinalis (Brassicaceae) has 16 orthologs in A. thaliana annotated as “putative tropine reductase” due to sequence identity of >50%. However, A. thaliana does not accumulate tropane alkaloids. Numerous tropinone reductaselike genes conserved in other Brassicaceae genomes suggest that those SDR form a reservoir for the evolution of secondary product enzymes. We will investigate catalytic characteristics of tropinone reductase-like SDR from Brassicaceae that form or do not form tropane alkaloids. SDR enzyme models serve for ligand identification by in silico pharmacophore search and comparison with known Brassicaceae metabolites. Promising ligands will be tested in vitro. Thus, metabolic flexibility and catalytic redundancy are defined, and hints for the native function of the SDR can be expected. Tropanes are tested as substrates to distinguish tropane-accepting SDR and residues decisive for tropinone binding. SDR are mutated to achieve or enhance tropinone reduction and test model-guided in vitro enzyme evolution.

该项目的目标是研究短链脱氢酶/还原酶 (SDR) 的催化能力和进化性，并获得有关其天然功能的信息，托品酮还原是由托品烷生物碱进行的托品酮还原酶的一个步骤。 -形成 Cochlearia officinalis（十字花科）在 A 中有 16 个直向同源物。由于序列同一性 >50%，拟南芥被注释为“假定的托品还原酶”。然而，其他十字花科基因组中保守的许多托品酮还原酶基因表明，这些 SDR 形成了次级产物进化的库。我们将研究来自十字花科的托品酮还原酶样 SDR 的催化特性。 SDR 酶模型通过计算机药效团搜索和与已知十字花科代谢物的比较来进行配体鉴定，从而确定代谢灵活性和催化冗余性，并提示其天然功能。 SDR 可以作为底物进行测试，以区分托烷接受 SDR，并且对托品酮结合起决定作用的残基发生突变。实现或增强托品酮减少并测试模型引导的体外酶进化。