Structural Analyses of Short-Chain Prenyltransfemses Identify an Evolutionarily Conserved GFPPS Clade in Brassicaceae Plants  

作　　者：ChengyuanWang Qingwen Chen Dongjie Fan Jianxu Li Guodong Wang Peng Zhang 

机构地区：[1]National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China [2]State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China [3]University of Chinese Academy of Sciences, Beijing 100039, China [4]These authors contributed equally to this article [5]Present address: National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China

出　　处：《Molecular Plant》2016年第2期195-204,共10页分子植物（英文版）

摘　　要：Terpenoids are the largest and most diverse class of plant-specialized metabolites, which function in diverse physiological processes during plant development. In the biosynthesis of plant terpenoids, short-chain prenyltransferases （SC-PTs）, together with terpene synthases （TPSs）, play critical roles in determining terpenoid diversity. SC-PTs biosynthesize prenyl pyrophosphates with different chain lengths, and these compounds are the direct precursors of terpenoids. Arabidopsis thaliana possesses a subgroup of SC-PTs whose functions are not clearly known. In this study, we focus on 10 geranylgeranyl pyro- phosphate synthase-like [GGPPSL] proteins, which are commonly thought to produce GGPP [C20]. We found that a subset of members of the Arabidopsis GGPPSL gene family have undergone neo- functionalization： GGPPSL6, 7, 9, and 10 mainly have geranylfarnesyl pyrophosphate synthase activity （C25; renamed AtGFPPS1, 2, 3, and 4）, and GGPPSL8 produces even longer chain prenyl pyrophosphate （〉C30; renamed polyprenyl pyrophosphate synthase 2, AtPPPS2）. By solving the crystal structures of AtGFPPS2, AtPPPS2, and AtGGPPS11, we reveal the product chain-length determination mechanism of SC-PTs and interpret it as a ＂three floors＂ model. Using this model, we identified a novel GFPPS clade distributed in Brassicaceae plants and found that the GFPPS gene typically occurs in tandem with a gene encoding a TPS, forming a GFPPS-TPS gene cluster.Terpenoids are the largest and most diverse class of plant-specialized metabolites, which function in diverse physiological processes during plant development. In the biosynthesis of plant terpenoids, short-chain prenyltransferases （SC-PTs）, together with terpene synthases （TPSs）, play critical roles in determining terpenoid diversity. SC-PTs biosynthesize prenyl pyrophosphates with different chain lengths, and these compounds are the direct precursors of terpenoids. Arabidopsis thaliana possesses a subgroup of SC-PTs whose functions are not clearly known. In this study, we focus on 10 geranylgeranyl pyro- phosphate synthase-like [GGPPSL] proteins, which are commonly thought to produce GGPP [C20]. We found that a subset of members of the Arabidopsis GGPPSL gene family have undergone neo- functionalization： GGPPSL6, 7, 9, and 10 mainly have geranylfarnesyl pyrophosphate synthase activity （C25; renamed AtGFPPS1, 2, 3, and 4）, and GGPPSL8 produces even longer chain prenyl pyrophosphate （〉C30; renamed polyprenyl pyrophosphate synthase 2, AtPPPS2）. By solving the crystal structures of AtGFPPS2, AtPPPS2, and AtGGPPS11, we reveal the product chain-length determination mechanism of SC-PTs and interpret it as a ＂three floors＂ model. Using this model, we identified a novel GFPPS clade distributed in Brassicaceae plants and found that the GFPPS gene typically occurs in tandem with a gene encoding a TPS, forming a GFPPS-TPS gene cluster.

关 键 词：TERPENOID PRENYLTRANSFERASE molecular basis product length determination geranylfarnesyl diphos-phate synthase crystal structure 

分 类 号：Q949.748.3[生物学—植物学] O342[理学—固体力学]