In silico, in vitro, and structural investigations on BAHD-enzymes from different species able to malonylate 21-hydroxypregnanes
In silico, in vitro, and structural investigations on BAHD-enzymes from different species able to malonylate 21-hydroxypregnanes
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对来自不同物种的能够丙二酰化 21-羟基孕烷的 BAHD 酶进行计算机、体外和结构研究
DOI：
10.1055/s-0041-1736873
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发表时间：
2021
期刊：
影响因子：
2.7
通讯作者：
W Kreis
中科院分区：
文献类型：
--
作者：
M Tropper;L-S Wolf;H Lanig;W Kreis
BAHD-酰基转移酶代表了被子植物中普遍存在的一个大酶家族。它们被认为是底物混杂的，接受从小的脂肪醇到复杂结构（例如萜类化合物或黄酮类化合物）的各种底物。 BAHD 使用不同的酰基辅酶 A 硫酯催化酯的形成，因此是特殊植物代谢的重要酶 [1]。假设卡烯内酯形成中的一个步骤，即 21-羟基孕烷的 21-O-丙二酰化，是由 BAHD-丙二酰转移酶 (21MaT) 催化的。为了筛选能够丙二酸 21-羟基孕烷的潜在候选者，我们从拟南芥中分离了 BAHD-丙二酰转移酶的 cDNA（在 PMaT1，At PMaT2)、Erysimum crepidifolium (Ec MaT1) 和毛地黄 (Dl MaT1)。为了预测底物接受度，生成了这些酶的同源模型。与这些模型的对接模拟表明，除了 At PMaT2 之外，所有测试的酶都接受 21-羟基孕烷作为底物 [2]。
BAHD-acyltransferases represent a large enzyme family found ubiquitously in angiosperms. They are considered substrate-promiscuous, accepting various substrates ranging from small aliphatic alcohols to complex structures such as terpenoids or flavonoids. BAHDs catalyze the formation of esters using different acyl-CoA thioesters and are thus important enzymes of specialized plant metabolism [1]. It is assumed that one step in cardenolide formation, the 21-O-malonylation of 21-hydroxypregnanes, is catalyzed by a BAHD-malonyltransferase (21MaT).To screen potential candidates able to malonate 21-hydroxypregnanes, we isolated cDNAs of BAHD-malonyltransferases from Arabidopsis thaliana (At PMaT1, At PMaT2), Erysimum crepidifolium (Ec MaT1) and Digitalis lanata (Dl MaT1). To predict substrate acceptance, homology models of these enzymes were generated. Docking simulations with those models implied that all tested enzymes, except At PMaT2, accept 21-hydroxypregnanes as substrates [2].