Promiscuous fatty acyl CoA ligases produce acyl-CoA and acyl-SNAC precursors for polyketide biosynthesis
Promiscuous fatty acyl CoA ligases produce acyl-CoA and acyl-SNAC precursors for polyketide biosynthesis
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DOI：
10.1021/ja052991s
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发表时间：
2005-07-06
影响因子：
15
通讯作者：
Gokhale, RS
中科院分区：
文献类型：
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作者：
Arora, P;Vats, A;Gokhale, RS
随着大量基因簇的克隆和测序，以及在异源宿主中操纵复杂的生物合成系统的同时，生物活性天然产物的研究取得了快速的进展。基因重组需要异源宿主拥有可供生物合成的底物池。聚酮合成酶(PKS)利用酰基辅酶A(CoA)前体，通过重复脱羧基缩合反应合成聚酮。在这里，我们展示了酰基辅酶A连接酶，它属于一个大的酰基激活酶家族，具有产生各种起始辅酶A前体的潜力，这些前体可以用于聚酮的生物合成。顺便说一句，在几个PKS和非核糖体多肽合成酶基因簇中已经发现了这样的蛋白结构域。我们对分枝杆菌脂肪酰辅酶A连接酶(FACL)的研究表明，对含有α，β，ω和ω−ν位修饰的各种脂肪酸具有显著的耐受性。这种底物的灵活性进一步扩展，使得这些蛋白质还有效地利用Coash的较短受体末端部分N-乙酰半胱胺来产生酰基-SNAC。我们表明，原位生成的酰基-COAS和酰基-SNAC可以被引导到I类和-III类PKS系统中产生新的代谢物。总而言之，FACL和PKS的混杂活动为扩大天然产品的保留范围提供了新的机会。
The study of bioactive natural products has undergone rapid advancement with the cloning and sequencing of large number of gene clusters and the concurrent progress to manipulate complex biosynthetic systems in heterologous hosts. The genetic reconstitution necessitates that the heterologous hosts possess substrate pools that could be coordinately supplied for biosynthesis. Polyketide synthases (PKS) utilize acyl-coenzyme A (CoA) precursors and synthesize polyketides by repetitive decarboxylative condensations. Here we show that acyl-CoA ligases, which belong to a large family of acyl-activating enzymes, possess potential to produce varied starter CoA precursors that could be utilized in polyketide biosynthesis. Incidentally, such protein domains have been recognized in several PKS and nonribosomal peptide synthetase gene clusters. Our studies with mycobacterial fatty acyl-CoA ligases (FACLs) show remarkable tolerance to activate a variety of fatty acids that contain modifications at α, β, ω, and ω−ν positions. This substrate flexibility extends further such that these proteins also efficiently utilizeN-acetyl cysteamine, the shorter acceptor terminal portion of CoASH, to produce acyl-SNACs. We show that the in situ generated acyl-CoAs and acyl-SNACs could be channeled to types I and -III PKS systems to produce new metabolites. Together, the promiscuous activity of FACL and PKSs provides new opportunities to expand the repertoire of natural products.