Delineating Substrate Diversity of Disparate Short-Chain Dehydrogenase Reductase from Debaryomyces hansenii.
Delineating Substrate Diversity of Disparate Short-Chain Dehydrogenase Reductase from Debaryomyces hansenii.
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从hansenii debaryomyces删除了不同短链脱氢酶还原酶的底物多样性。
DOI：
10.1371/journal.pone.0170202
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发表时间：
2017
期刊：
影响因子：
3.7
通讯作者：
Venkatraman J
中科院分区：
文献类型：
--
作者：
Ghatak A;Bharatham N;Shanbhag AP;Datta S;Venkatraman J
短链脱氢酶还原酶（SDR）已被用于催化许多芳香族/脂肪族前手性酮还原为它们各自的醇。然而，有一个缺乏的数据，阐明其固有的生物学作用和不同的基板空间。在这项研究中，我们执行了深入的生化表征和底物空间映射（278前手性酮）的未注释的SDR（DHK）从汉逊德巴利酵母，并比较它与结构和功能特征的SDR细长聚球藻。PCC 7942 FabG以描述其工业意义。观察到DHK比FabG显著更有效，减少了多种酮，尽管转化率更高。FabG结构与DHK的同源性模型和底物与两种结构的对接的比较揭示了DHK的底物结合位点附近存在额外的柔性环。比较弹性的辅因子和底物结合位点的FabG和DHK实验证实，使用差示扫描荧光法。据推测，环的灵活性可能占的上级催化效率的DHK，虽然定位的催化三元组是保守的。
Short-chain dehydrogenase reductases (SDRs) have been utilized for catalyzing the reduction of many aromatic/aliphatic prochiral ketones to their respective alcohols. However, there is a paucity of data that elucidates their innate biological role and diverse substrate space. In this study, we executed an in-depth biochemical characterization and substrate space mapping (with 278 prochiral ketones) of an unannotated SDR (DHK) from Debaryomyces hansenii and compared it with structurally and functionally characterized SDR Synechococcus elongatus. PCC 7942 FabG to delineate its industrial significance. It was observed that DHK was significantly more efficient than FabG, reducing a diverse set of ketones albeit at higher conversion rates. Comparison of the FabG structure with a homology model of DHK and a docking of substrate to both structures revealed the presence of additional flexible loops near the substrate binding site of DHK. The comparative elasticity of the cofactor and substrate binding site of FabG and DHK was experimentally substantiated using differential scanning fluorimetry. It is postulated that the loop flexibility may account for the superior catalytic efficiency of DHK although the positioning of the catalytic triad is conserved.