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.

该项目的目的是研究短链脱氢酶/还原酶（SDR）的催化能力和可变性，并获取有关其天然功能的信息。肌钙酮还原是SDR进行的Tropane生物碱生物合成的一步。由于序列的身份> 50％，因此从tropane生物碱形成的耳目研究中减少了tropinone降低，在thaliana的A. thaliana中具有16个直系同源物。但是，塔利亚纳曲霉不会积聚tropane生物碱。许多在其他胸肌基因组中保守的肌动酮可减少基因表明，这些SDR构成了二级产物酶进化的储层。我们将研究来自形成或不形成tropane生物碱的黄铜科的肌动酮还原酶样SDR的催化特性。 SDR酶模型用于通过计算机药效团搜索中的配体鉴定，并与已知的胸肌代谢物进行比较。有希望的配体将在体外测试。这是定义代谢柔韧性和催化冗余的，并且可以预期SDR的天然功能的提示。对肌烷进行了测试，以区分底型sdr，并保留对肌氨酸结合的决定性作用。 SDR被突变以实现或增强肌动酮还原并在体外酶演化中引入测试模型。