Du Yu, Derewacz Dagmara K, Deguire Sean M, Teske Jesse, Ravel Jacques, Sulikowski Gary A, Bachmann Brian O
Departments of Chemistry and Biochemistry, Institute of Chemical Biology, Vanderbilt University, Nashville, TN 77842-3012, U.S.A.
Tetrahedron. 2011 Sep 2;67(35):6568-6575. doi: 10.1016/j.tet.2011.05.106.
The apoptolidins are 20/21-membered macrolides produced by Nocardiopsis sp. FU40. Several members of this family are potent and remarkably selective inducers of apoptosis in cancer cell lines, likely via a distinct mitochondria associated target. To investigate the biosynthesis of this natural product, the complete genome of the apoptolidin producer Nocardiopsis sp. FU40 was sequenced and a 116 Kb region was identified containing a putative apoptolidin biosynthetic gene cluster. The apoptolidin gene cluster comprises a type I polyketide synthase, with 13 homologating modules, apparently initiated in an unprecedented fashion via transfer from a methoxymalonyl-acyl carrier protein loading module. Spanning approximately 39 open reading frames, the gene cluster was cloned into a series of overlapping cosmids and functionally validated by targeted gene disruption experiments in the producing organism. Disruption of putative PKS and P(450) genes delineated the roles of these genes in apoptolidin biosynthesis and chemical complementation studies demonstrated intact biosynthesis peripheral to the disrupted genes. This work provides insight into details of the biosynthesis of this biologically significant natural product and provides a basis for future mutasynthetic methods for the generation of non-natural apopotolidins.
凋亡菌素是由诺卡氏菌属菌株FU40产生的20/21元大环内酯类化合物。该家族的几个成员是癌细胞系中凋亡的强效且极具选择性的诱导剂，可能是通过一个独特的与线粒体相关的靶点起作用。为了研究这种天然产物的生物合成，对凋亡菌素产生菌诺卡氏菌属菌株FU40的全基因组进行了测序，并鉴定出一个116 Kb的区域，其中包含一个假定的凋亡菌素生物合成基因簇。凋亡菌素基因簇包含一个I型聚酮合酶，有13个同源模块，显然是以一种前所未有的方式通过从甲氧基丙二酰 - 酰基载体蛋白装载模块转移起始的。该基因簇跨越约39个开放阅读框，被克隆到一系列重叠的黏粒中，并通过在产生菌中进行的靶向基因破坏实验进行了功能验证。假定的聚酮合酶和P(450)基因的破坏确定了这些基因在凋亡菌素生物合成中的作用，化学互补研究表明在被破坏基因周围的生物合成是完整的。这项工作深入了解了这种具有生物学意义的天然产物的生物合成细节，并为未来生成非天然凋亡菌素的突变合成方法提供了基础。
