Insights into Bacterial 6-Methylsalicylic Acid Synthase and Its Engineering to Orsellinic Acid Synthase for Spirotetronate Generation
Insights into Bacterial 6-Methylsalicylic Acid Synthase and Its Engineering to Orsellinic Acid Synthase for Spirotetronate Generation
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深入了解细菌 6-甲基水杨酸合酶及其对用于螺四酯生成的奥赛林酸合酶的改造
DOI：
10.1016/j.chembiol.2010.04.009
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发表时间：
2010-05-28
影响因子：
--
通讯作者：
Liu, Wen
中科院分区：
文献类型：
--
作者：
Ding, Wei;Lei, Chun;Liu, Wen
6-甲基水杨酸（6-MSA）合成酶（6-MSASs）参与真菌和细菌产生的许多生物活性次生代谢产物中芳基片段的构建。以细菌6-MSAS ChIB1为模型，通过位点特异性诱变对其脱水酶（DH）和酮还原酶（KR）结构域进行功能分析，发现选择性酮还原对聚酮链延伸并不是必需的。在β功能识别中，酮酰合酶结构域的混杂性允许通过在活性位点失活KR来将ChIB1改造为orsellinic acid （OSA）合成酶（OSAS）。工程ChIB1与CHL生物合成后期剪裁酶兼容，具有促进可变芳基结合的特异性蛋白质识别。所得到的螺戊酸酯具有osa衍生的芳基，其抗菌活性与母体产品相当。
The enzymes 6-methylsalicylic acid (6-MSA) synthases (6-MSASs) are involved in the building of an aryl moiety in many bioactive secondary metabolites produced by fungi and bacteria. Using the bacterial 6-MSAS ChIB1 in the biosynthesis of spirotetronate antibiotic chlorothricin (CHL) as a model, functional analysis of its dehydratase (DH) and ketoreductase (KR) domains by site-specific mutagenesis revealed that selective ketoreduction is not essential for polyketide chain extension. Promiscuity of the ketoacylsynthase domain in beta functionality recognition allows for engineering ChIB1 to an orsellinic acid (OSA) synthase (OSAS) by inactivating KR at the active site. The engineered ChIB1 is compatible with the enzymes for late-stage tailoring in CHL biosynthesis, featuring specific protein recognitions that facilitate variable aryl group incorporation. The resulting spirotetronates, which bear an OSA-derived aryl group, exhibited antibacterial activities comparable to those of the parent products.