Institute of Microbiology, Eidgenössische Technische Hochschule (ETH) Zürich, Vladimir-Prelog-Weg 4, 8093, Zürich, Switzerland.
Université de Lorraine, CNRS, IMoPA, 54000, Nancy, France.
Angew Chem Int Ed Engl. 2023 Aug 21;62(34):e202304481. doi: 10.1002/anie.202304481. Epub 2023 Jul 11.
Modular trans-acyltransferase polyketide synthases (trans-AT PKSs) are enzymatic assembly lines that biosynthesize complex polyketide natural products. Relative to their better studied cis-AT counterparts, the trans-AT PKSs introduce remarkable chemical diversity into their polyketide products. A notable example is the lobatamide A PKS, which incorporates a methylated oxime. Here we demonstrate biochemically that this functionality is installed on-line by an unusual oxygenase-containing bimodule. Furthermore, analysis of the oxygenase crystal structure coupled with site-directed mutagenesis allows us to propose a model for catalysis, as well as identifying key protein-protein interactions that support this chemistry. Overall, our work adds oxime-forming machinery to the biomolecular toolbox available for trans-AT PKS engineering, opening the way to introducing such masked aldehyde functionalities into diverse polyketides.
模块化的反式酰基转移聚酮合酶（trans-AT PKSs）是生物合成复杂聚酮天然产物的酶组装线。与它们研究得更好的顺式 AT 对应物相比，trans-AT PKSs 在它们的聚酮产物中引入了显著的化学多样性。一个值得注意的例子是 lobatamide A PKS，它包含一个甲基化的肟。在这里，我们通过一个不寻常的含有氧合酶的双模块在生化上证明了这一功能是在线安装的。此外，对氧合酶晶体结构的分析与定点突变相结合，使我们能够提出一个催化模型，并确定支持这种化学的关键蛋白-蛋白相互作用。总的来说，我们的工作为 trans-AT PKS 工程提供了肟形成机制，为将这种掩蔽醛功能引入到不同的聚酮中开辟了道路。
