Cloning and characterization of novel methylsalicylic acid synthase gene involved in the biosynthesis of isoasperlactone and asperlactone in Aspergillus westerdijkiae
Cloning and characterization of novel methylsalicylic acid synthase gene involved in the biosynthesis of isoasperlactone and asperlactone in Aspergillus westerdijkiae
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DOI：
10.1016/j.fgb.2009.07.002
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发表时间：
2009-10-01
影响因子：
3
通讯作者：
Lebrihi, Ahmed
中科院分区：
文献类型：
--
作者：
Bacha, Nafees;Dao, Huy Phong;Lebrihi, Ahmed
韦斯特迪基曲霉 (Aspergillus westerdijkiae) 是多种生物活性聚酮代谢物的主要生产者，包括异天门内酯和天门内酯。通过使用基因步移方法和RACE-PCR，已经在Westerdijkiae曲霉中克隆了聚酮合酶基因“aomsas”的5298。 aomsas 的预测氨基酸序列与白衣衣藻、P. patulum、A. terreus 和 Streptomyces viridochromogenes 中发现的不同甲基水杨酸合酶基因具有 40-56% 的同一性。基于逆转录PCR和动力学次级代谢产物产生研究，发现aomsas表达与异天门内酯和天门内酯的生物合成相关。此外，A. westerdijkiae的aomsas敲除突变体“ao Delta msas”不仅丧失了产生异天门内酯和天门内酯的能力，而且还失去了产生6-甲基水杨酸的能力。基因互补的突变体 ao+msas 恢复了所有缺失代谢物的生物合成。通过向 ao Delta msas 突变体的生长培养物中添加 6-甲基水杨酸、阿斯吡酮和双环氧化合物进行化学互补，结果表明这些化合物在阿斯帕内酯和异阿斯帕内酯的生物合成中发挥中间作用。 (C) 2009 Elsevier Inc. 保留所有权利。
Aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. A 5298 by polyketide synthase gene "aomsas" has been cloned in Aspergillus westerdijkiae by using gene walking approach and RACE-PCR. The predicted amino acid sequence of aomsas shows an identity of 40-56% with different methylsalicylic acid synthase genes found in Byssochlamys nivea, P. patulum, A. terreus and Streptomyces viridochromogenes. Based on the reverse transcription PCR and kinetic secondary metabolites production studies, aomsas expression was found to be associated with the biosynthesis of isoasperlactone and asperlactone. Moreover an aomsas knockout mutant "ao Delta msas" of A. westerdijkiae, not only lost the capacity to produce isoasperlactone and asperlactone, but also 6-methylsalicylic acid. The genetically complemented mutant ao+msas restored the biosynthesis of all the missing metabolites. Chemical complementation through the addition of 6-methylsalicylic acid, aspyrone and diepoxide to growing culture of ao Delta msas mutant revealed that these compounds play intermediate roles in the biosynthesis of asperlactone and isoasperlactone. (C) 2009 Elsevier Inc. All rights reserved.