Identification of a polyketide biosynthesis gene cluster by transcriptional regulator activation in Aspergillus terreus
Identification of a polyketide biosynthesis gene cluster by transcriptional regulator activation in Aspergillus terreus
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通过土曲霉转录调节因子激活鉴定聚酮化合物生物合成基因簇
DOI：
10.1016/j.fgb.2022.103690
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发表时间：
2022-03-29
影响因子：
3
通讯作者：
Lu, Xuefeng
中科院分区：
文献类型：
--
作者：
Tang, Shen;Men, Ping;Lu, Xuefeng
在丝状真菌中，次生代谢是环境敏感的。大多数生物合成的次生代谢物基因簇在实验室条件下是沉默的。在本研究中，在土曲霉MEFC01的基因组序列中鉴定到一个高度保守的萘比酮PKS ATEG_06206。这种基因在实验室条件下是沉默的。为了研究该蛋白系统的功能，我们在A.terreus MEFC01中通过替换簇特异性转录因子ATEG_06205的启动子来激活沉默的生物合成途径。通过这一策略，我们证实了这种神秘的PKS的产物是萘醌类化合物。这些萘醌类化合物是一种可溶性色素，可以分泌到琼脂培养基和发酵液中。因此，被激活的突变体的菌丝和分生孢子的颜色明显比亲本菌株暗。通过反向遗传学方法和体外酶促分析进一步阐明了该基因簇和生物合成途径。
In filamentous fungi, the secondary metabolism is environmentally sensitive. Most of the biosynthetic gene clusters of secondary metabolites are silent under laboratory conditions. In this study, a highly conserved naphthopyrone PKS ATEG_06206 was identified in the genome sequence of A. terreus MEFC01. This gene is silent under laboratory conditions. To study the function of this PKS, we activated the silent biosynthetic pathway by replacing the promoter of cluster-specific transcriptional factor ATEG_06205 in A. terreus MEFC01. With this strategy, we confirmed that the products of this cryptic PKS are naphthoquinones. These naphthoquinones are soluble pigments, which could be secreted into the agar medium and culture broth. For this reason, the colour of mycelium and conidia of the activated mutant was significantly darker than that of the parental strain. The gene cluster and biosynthetic pathway were further elucidated through the reverse genetics approach and enzymatic assay in vitro.