Tang Man-Cheng, Lin Hsiao-Ching, Li Dehai, Zou Yi, Li Jian, Xu Wei, Cacho Ralph A, Hillenmeyer Maureen E, Garg Neil K, Tang Yi
Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao, Shandong 266003, P. R. China.
Stanford Genome Technology Center, Stanford University , Palo Alto, California 94304, United States.
J Am Chem Soc. 2015 Nov 4;137(43):13724-7. doi: 10.1021/jacs.5b06108. Epub 2015 Oct 21.
The structural diversity and biological activities of fungal indole diterpenes (IDTs) are generated in large part by the IDT cyclases (IDTCs). Identifying different IDTCs from IDT biosynthetic pathways is therefore important toward understanding how these enzymes introduce chemical diversity from a common linear precursor. However, IDTCs involved in the cyclization of the well-known aflavinine subgroup of IDTs have not been discovered. Here, using Saccharomyces cerevisiae as a heterologous host and a phylogenetically guided enzyme mining approach, we combinatorially assembled IDT biosynthetic pathways using IDTCs homologues identified from different fungal hosts. We identified the genetically standalone IDTCs involved in the cyclization of aflavinine and anominine and produced new IDTs not previously isolated. The cyclization mechanisms of the new IDTCs were proposed based on the yeast reconstitution results. Our studies demonstrate heterologous pathway assembly is a useful tool in the reconstitution of unclustered biosynthetic pathways.
真菌吲哚二萜（IDTs）的结构多样性和生物活性很大程度上是由IDT环化酶（IDTCs）产生的。因此，从IDT生物合成途径中鉴定不同的IDTCs对于理解这些酶如何从共同的线性前体引入化学多样性至关重要。然而，尚未发现参与IDTs中著名的阿弗拉文宁亚组环化的IDTCs。在这里，我们以酿酒酵母作为异源宿主，并采用系统发育导向的酶挖掘方法，使用从不同真菌宿主中鉴定出的IDTCs同源物组合组装IDT生物合成途径。我们鉴定出了参与阿弗拉文宁和阿诺宁环化的独立基因IDTCs，并产生了以前未分离出的新IDTs。基于酵母重组结果提出了新IDTCs的环化机制。我们的研究表明，异源途径组装是重建非聚集生物合成途径的有用工具。
