iso-Migrastatin, Migrastatin, and Dorrigocin Production in Streptomyces platensis NRRL 18993 Is Governed by a Single Biosynthetic Machinery Featuring an Acyltransferase-less Type I Polyketide Synthase
iso-Migrastatin, Migrastatin, and Dorrigocin Production in Streptomyces platensis NRRL 18993 Is Governed by a Single Biosynthetic Machinery Featuring an Acyltransferase-less Type I Polyketide Synthase
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DOI：
10.1074/jbc.m109.046805
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发表时间：
2009-10-23
影响因子：
4.8
通讯作者：
Shen, Ben
中科院分区：
文献类型：
--
作者：
Lim, Si-Kyu;Ju, Jianhua;Shen, Ben
异米格雷他汀和相关的含有戊二酰亚胺的聚酮是肿瘤细胞迁移的有效抑制剂，它们作为抗肿瘤转移药物的潜在潜力已经引起了人们的极大关注。钝顶链霉菌NRRL 18993的基因组扫描揭示了两个候选基因簇(088D和mgs)；每个基因簇编码与异米格雷他汀生物合成相称的酰基转移酶I型聚酮合成酶。在钝顶链霉菌中，这两个簇都被lambda-red介导的PCR靶向突变失活；Delta mgsF突变株SB11012中异偏头痛抑素的产生完全被取消，而088D-orf7的失活产生了SB11006菌株，其异偏头痛抑素的生物合成没有明显的变化。这些数据表明，异米曲他汀类药物的生产受mgs集群的控制。系统的基因失活可以确定mgs簇的精确边界和mgs簇内基因在异米曲斯汀生产中的重要性。MGS簇由11个开放阅读框组成，编码3个酰基转移酶I型聚酮合成酶(MgsEFG)、1个离散酰基转移酶(MgsH)、1个II型硫代酯酶(MgsB)、3个PKS后剪裁酶(MgsIJK)、2个戊二酰亚胺生物合成酶(MgsCD)和1个调节蛋白(MgsA)。基于生物信息学的功能分配，提出了异米孕酮生物合成的模型，并得到了体内基因失活实验的进一步支持。
iso-Migrastatin and related glutarimide-containing polyketides are potent inhibitors of tumor cell migration and their implied potential as antimetastatic agents for human cancers has garnered significant attention. Genome scanning of Streptomyces platensis NRRL 18993 unveiled two candidate gene clusters (088D and mgs); each encodes acyltransferase-less type I polyketide synthases commensurate with iso-migrastatin biosynthesis. Both clusters were inactivated by lambda-RED-mediated PCR-targeting mutagenesis in S. platensis; iso-migrastatin production was completely abolished in the Delta mgsF mutant SB11012 strain, whereas inactivation of 088D-orf7 yielded the SB11006 strain that exhibited no discernible change in iso-migrastatin biosynthesis. These data indicate that iso-migrastatin production is governed by the mgs cluster. Systematic gene inactivation allowed determination of the precise boundaries of the mgs cluster and the essentiality of the genes within the mgs cluster in iso-migrastatin production. The mgs cluster consists of 11 open reading frames that encode three acyltransferase-less type I polyketide synthases (MgsEFG), one discrete acyltransferase (MgsH), a type II thioesterase (MgsB), three post-PKS tailoring enzymes (MgsIJK), two glutarimide biosynthesis enzymes (MgsCD), and one regulatory protein (MgsA). A model for iso-migrastatin biosynthesis is proposed based on functional assignments derived from bioinformatics and is further supported by the results of in vivo gene inactivation experiments.