Enzymatic Amide Tailoring Promotes Retro-Aldol Amino Acid Conversion To Form the Antifungal Agent Aspirochlorine
Enzymatic Amide Tailoring Promotes Retro-Aldol Amino Acid Conversion To Form the Antifungal Agent Aspirochlorine
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DOI：
10.1002/anie.201806740
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发表时间：
2018-10-22
影响因子：
16.6
通讯作者：
Hertweck, Christian
中科院分区：
文献类型：
--
作者：
Tsunematsu, Yuta;Maeda, Naoya;Hertweck, Christian
阿螺氯林是一种不寻常的抗真菌环肽，由米曲霉产生，米曲霉是一种用于食品发酵的重要霉菌。虽然其结构表明非核糖体肽合成酶从苯丙氨酸和甘氨酸结构单元组装环肽，但标记研究表明一个 Phe 部分在肽形成后转化为 Gly。通过基因工程、异源表达、生物转化和体外测定，我们解剖并重建了阿螺氯生物合成的四个关键步骤，其中涉及两种细胞色素P450单加氧酶（AclL和AclO）、甲基转移酶（AclU）和卤化酶（AclH）。我们发现肽键 N-甲氧基化的安装为逆羟醛反应奠定了基础，从而导致苯丙氨酸到甘氨酸的转化。专用酶的底物范围以及生物测定表明，肽编辑已经发展到优化天然产物的抗真菌作用。
Aspirochlorine is an unusual antifungal cyclopeptide produced by Aspergillus oryzae, an important mold used for food fermentation. Whereas its structure suggested that a non-ribosomal peptide synthetase assembles the cyclopeptide from phenylalanine and glycine building blocks, labeling studies indicated that one Phe moiety is transformed into Gly after peptide formation. By means of genetic engineering, heterologous expression, biotransformations, and invitro assays, we dissected and reconstituted four crucial steps in aspirochlorine biosynthesis, which involve two cytochrome P450 monooxygenases, (AclL and AclO), a methyltransferase (AclU), and a halogenase (AclH). We found that the installation of the N-methoxylation of the peptide bond sets the stage for a retro-aldol reaction that leads to the Phe-to-Gly conversion. The substrate scopes of the dedicated enzymes as well as bioassays revealed that the peptide editing has evolved to optimize the antifungal action of the natural product.