海洋放线菌Streptomyces costaricanus SCSIO ZS0073中fungichromin生物合成基因簇的分析鉴定

目的 对分离自我国广西红沙红树林湿地公园的放线菌菌株Streptomyces costaricanus SCSIO ZS0073进行基因组测序分析,并对其生产的制霉色基素(fungichromin)的生物合成基因簇进行分析鉴定。 方法 对S. costaricanus SCSIO ZS0073菌株进行基因组提取,利用Highseq4000和PacBio SMRT技术相结合的手段对该菌株进行了基因组完成图测序；利用生物信息学方法对基因组进行注释并寻找fungichromin的生物合成基因簇,对fungichromin生物合成骨架基因fgmJ1进行置换突变,确定fungichromin生物合成基因簇,结合fungichromin结构特征和其基因簇内遗传信息及聚酮化合物的生物合成原理,对其生物合成途径进行推测。 结果 全基因组测序发现S. costaricanus SCSIO ZS0073菌株基因组含有一条线性染色体和一个圆形质粒,基因组含有36个次级代谢产物生物合成基因簇。利用基因敲除手段对fungichromin的生物合成基因簇进行了确认并进行了生物合成途径推导。 结论 fungichromin生物合成基因簇的确定和生物合成途径的推导为该化合物的基因工程改造研究奠定了分子基础。

Identification of the fungichromin biosynthetic pathway from Streptomyces costaricanus SCSIO ZS0073

Objective To obtain the genome information of Stremptomyces costaricanus SCSIO ZS0073 isolated from Hongsha Park (Guangxi, China) and identify the biosynthetic gene cluster responsible for its main product -fungichromin. Methods The genomic DNA of strain S. costaricanus SCSIO ZS0073 was extracted, sequenced using a combination of the second generation Highseq4000 and the third generation PacBio SMRT technology and assembled; the biosynthetic pathway of secondary metabolites were annotated by bioinformatics method. Results Whole genome sequencing revealed that strain S. costaricanus SCSIO ZS0073 contains a linear chromosome as well as a circle plasmid. The antiSMASH annotation results showed that there are 36 secondary metabolites biosynthetic gene clusters in the genome of S. costaricanus SCSIO ZS0073. The gene cluster of fungichromin was identified by bioinformatics analysis and gene inactivation methods. Conclusion The identification of the biosynthetic pathway of fungichromin lays a molecular foundation for future genetic engineering to produce additional antifungal regents.