Functional Genomics Approach to Exploiting Molecular Diversity

(1)利用基因组信息，从高等植物、蕨类植物和丝状真菌中克隆了24个新的三萜合酶基因。通过在酵母中异源表达鉴定了它们的酶功能。(2)作为这些三萜醇解酶的产物，鉴定了三种具有新骨架的新三萜。(3)首次在植物界发现羊毛甾醇合成酶基因，证实了植物甾醇通过羊毛甾醇合成途径的存在。(4)通过与非生理底物和合成底物类似物的反应，获得了五种新的类异戊二烯。（5）分别克隆了三种新的氧化酶和糖转移酶，并鉴定了它们的功能。(6)从丝状真菌中克隆了11个新的迭代聚酮合酶（i-PKS）基因。通过在异源真菌菌株中的表达鉴定了它们的酶功能。(7)六个新的聚酮化合物具有独特的结构被确定为这些i-PKS的产品。(8)在Asp基因组中鉴定出4个III型i-PKS基因。其中一个被证明编码地衣酸合酶。(9)作为I型i-PKS的高级结构，提出了一种新的同源四聚体模型。(10)作为新的聚酮修饰酶，我们克隆了一种短链酶、一种脱氢酶、一种具有环加成活性的氧化酶和两种异戊烯基转移酶，并鉴定了它们的功能。

(1) By utilizing genomic information, twenty four new triterpene synthase genes were cloned from higher plants, ferns and filamentous fungi. Their enzyme functions were identified by heterologous expression in yeast.(2) As the products of these triterpene synthases, three new triterpenes with novel skeletons were identified.(3) Lanosterol synthase genes were discovered for the first time from the plant kingdom and the presence of biosynthetic pathway of phytosterols via lanosterol was demonstrated.(4) By reacting triterpene synthases with non-physiological substrates and synthetic substrate analogues, five new polyprenoids were obtained(5) Each three novel oxidases and sugartransferases were cloned and their functions identified as the triterpene modifying enzymes.(6) Eleven new iterative polyketide synthase (i-PKS) genes were cloned from filamentous fungi. Their enzyme functions were identified by expression in a heterologous fungal strain.(7) Six new polyketide compounds with unique structures were identified as the products of these i-PKSs.(8) Four Type-III i-PKS genes were identified in the genome of Asp. oryzae and one of them was demonstrated to encode an orsellinic acid synthase.(9) As the higher structure for Type-I i-PKSs, a novel homo-tetramer model was proposed.(10) As the novel polyketide modifying enzymes, a chain-shortening enzyme, a dehydratase, an oxidase with cycloaddition activity and two prenyltrasferase were cloned and their enzyme functions identified.