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个新的三萜合成酶基因。通过酵母的异源表达鉴定了它们的酶功能。(2)作为这些三萜合成酶的产物，鉴定出3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，证明了植物甾醇通过羊毛甾醇生物合成途径的存在。(4)通过三萜合成酶与非生理底物及合成底物类似物的反应，获得了5个新的聚戊二烯类化合物。(5)分别克隆了3个新的氧化酶和糖转移酶，并鉴定了它们的功能为三萜修饰酶。(6)从丝状真菌中克隆了11个新的迭代聚酮合成酶（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)鉴定出6个结构独特的新聚酮化合物是这些i-PKSs的产物。(8)在Asp基因组中鉴定出4个iii型i-PKS基因。其中一种被证明编码一种orsellinic acid合成酶。(9)作为i型i-PKSs的高级结构，提出了一种新的同质四聚体模型。（10）克隆了1个链缩短酶、1个脱水酶、1个具有环加成活性的氧化酶和2个戊烯基转移酶，并鉴定了它们的酶功能。

(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.