PDF(Pubmed)
Abstract：
Sesquiterpenoids served as an important source for natural product drug discovery. Although genome mining approaches have revealed numerous novel sesquiterpenoids and biosynthetic enzymes, the comprehensive landscape of fungal sesquiterpene synthases (STSs) remains elusive. In this study, 123 previously reported fungal STSs were subjected to phylogenetic analysis, resulting in the identification of a fungi-specific STS family known as trichodiene synthase-like sesquiterpene synthases (TDTSs). Subsequently, the application of hidden Markov models allowed the discovery of 517 TDTSs from our in-house fungi genome library of over 400 sequenced genomes, and these TDTSs were defined into 79 families based on a sequence similarity network. Based on the novelty of protein sequences and the completeness of their biosynthetic gene clusters, 23 TDTS genes were selected for heterologous expression in Aspergillus oryzae. In total, 10 TDTSs were active and collectively produced 12 mono- and sesquiterpenes, resulting in the identification of the first chamipinene synthase, as well as the first fungi-derived cedrene, sabinene, and camphene synthases. Additionally, with the guidance of functionally characterized TDTSs, we found that TDTSs in Family 1 could produce bridged-cyclic sesquiterpenes, while those in Family 2 could synthesize spiro- and bridged-cyclic sesquiterpenes. Our research presents a new avenue for the genome mining of fungal sesquiterpenoids.
摘要：
倍半萜类化合物是天然产物药物发现的重要来源。尽管基因组挖掘方法已经揭示了许多新的倍半萜和生物合成酶，真菌倍半萜合酶（STSs）的综合景观仍然难以捉摸。在这项研究中,对123个先前报告的真菌STS进行了系统发育分析，从而鉴定出一种真菌特异性STS家族，称为三聚二烯合酶样倍半萜合酶（TDTS）。随后，隐马尔可夫模型的应用允许从我们的400多个测序基因组的内部真菌基因组文库中发现517个TDTS，根据序列相似性网络将这些TDTS定义为79个家族。基于蛋白质序列的新颖性及其生物合成基因簇的完整性，选择23个TDTS基因用于在米曲霉中异源表达。总的来说,10个TDTS是活跃的，集体产生12个单萜和倍半萜，结果鉴定出了第一个亚米品烯合成酶，以及第一种真菌衍生的cedrene，Sabinene,和樟脑烯合酶.此外,在功能特征化的TDTS的指导下，我们发现家族1中的TDTS可以产生桥环倍半萜，而家族2中的那些可以合成螺环和桥环倍半萜。我们的研究为真菌倍半萜类的基因组挖掘提供了新的途径。
