Characterization of a carboxyl methyltransferase in Fusarium graminearum provides insights into the biosynthesis of fusarin A
Characterization of a carboxyl methyltransferase in Fusarium graminearum provides insights into the biosynthesis of fusarin A
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禾谷镰刀菌中羧基甲基转移酶的表征为镰刀菌素 A 的生物合成提供了见解
DOI：
10.1039/d1ob01010g
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发表时间：
2021
影响因子：
3.2
通讯作者：
Liu Wen
中科院分区：
文献类型：
--
作者：
Yang Qian;Wang Wanqiu;Lin Yueting;Lin Yuqi;Tang Zhijun;Wang Jing;Tao Jiang;Tang Weihua;Liu Wen
禾谷镰刀菌是一种主要的真菌病原菌，通过产生多种真菌毒素而引起一系列毁灭性的农作物病害。梭菌素是一类聚酮-非核糖体肽杂交物。在镰刀菌毒素中，可变的2-吡咯烷酮环与甲酯部分取代的多烯链结合。赤霉素A是镰刀菌素家族的主要成员，具有四氢呋喃偶联的吡咯烷酮环，其在禾谷镰刀菌中形成的酶途径尚未确定。以镰刀菌素A生物合成的最后一步为目标，我们报道了一种S-腺苷蛋氨酸依赖的羧甲基转移酶，该酶在体内通过基因失活、关键的镰刀菌素中间体的分离和鉴定以及体外生化特性参与甲酯部分的形成。此外，生物活性测定表明甲酯是赤霉素A细胞毒性所必需的。
Fusarium graminearum is a major fungal pathogen that causes a series of devastating crop diseases by producing a variety of mycotoxins. Fusarins are a class of polyketide-nonribosomal peptide hybrids. In Fusarium mycotoxins, a variable 2-pyrrolidone ring conjugates with a polyene chain substituted with a methyl ester moiety. The enzymatic route through which fusarin A, a major member of the fusarin family with a characteristic tetrohydrofuran-coupled pyrrolidone ring, is formed in F. graminearum has not been established. By targeting the final step in the biosynthesis of fusarin A, we report here an S-adenosyl methionine-dependent carboxyl methyltransferase responsible for the formation of the methyl ester moiety by in vivo gene inactivation, isolation and characterization of a key fusarin intermediate, and in vitro biochemical characterization. Related findings provide insights into the poorly understood biosynthetic pathway of fusarin A. Additionally, bioactivity assays demonstrate that the methyl ester is necessary for fusarin cytotoxicity.