苎麻咖啡酰辅酶A甲基转移酶基因原核表达及其结构分析

High-level Expression Ramie Caffeoyl-CoA 3-O-methyltransferase Gene in E.coli

为了研究苎麻木质素合成关键酶——咖啡酰辅酶A-甲基转移酶(CCoAOMT)基因编码的酶蛋白,了解其结构特点;采用原核表达系统——大肠杆菌表达系统pQE,对苎麻CCoAOMT cDNA编码区进行了高效表达,获得了分子量为29.4kD的苎麻CCoAOMT融合蛋白。采用SwissModel服务器模拟构建了该酶蛋白的空间结构。并利用InsightII软件包中的Docking模块构建了该酶蛋白与辅酶Sinapoyl、SAH和Ca2+相互作用的复合物的结合模型,并利用Discover模块对模拟的结构进行结构优化。可以推知所克隆的苎麻CCoAOMT cDNA编码了咖啡酰辅酶A甲基转移酶,具有O-甲基转移酶蛋白典型的催化功能,参与苎麻木质素单体前体的甲基化反应。

Abstract： Ramie caffeoyl-CoA 3- O-methyltransferase was expressed by pQE High-level Expression system in E.coli. The molecular weight of Ramie Fusion caffeoyl-CoA3- O-methyhransferase is 29.4 kD. The structure of the enzyme has been constructed by SwissModel server. Multiplex structure of the enzyme, Sinapoyl CoA, SAH and Ca2＋ has been constructed by Docking module in software InsightII,and has been optimized by Discover module. It can be presume that Ramie caffeoyl-CoA 3- O-methyhransferase has catalyse function of O-methyhransferase, must been related to lignin monomer precursor methyhransfer.