Sansanmycin生物合成基因簇在天蓝色链霉菌中的异源表达

Cloning and heterologous expression of sansanmycin biosynthetic gene cluster in Streptomyces coelicolor

Sansanmycins(SSs)是一类由Streptomyces sp.SS产生的尿苷肽类抗生素,具有抗结核分枝杆菌和铜绿假单胞菌活性。该类化合物主要是由4',5'-烯胺-3'-脱氧尿苷通过肽键与假四肽肽链中的N-甲基-2,3-二氨基丁酰基(DABA)相连。为了研究相关基因的功能,进一步利用合成生物学的手段获得SSs的新结构衍生物,本实验克隆了完整的SS生物合成基因簇,并将其在天蓝色链霉菌M1146、M1152和M1154中异源表达。借助于HPLC和LC-HRMS/MS等对重组菌株的发酵液进行分析,结果表明三株异源表达菌株均能产生SS-A,而且M1154异源表达菌株的SS-A产量与未退化的野生型菌株相当。同时从M1154异源表达菌株发酵液中发现了一个可能为新结构的SS类似物SS-1154。

Sansanmycins （SSs）, produced by Streptomyces sp. SS, belong to uridyl peptide antibiotics which exhibit a good inhibitory effect on Mycobacterium tuberculosis and Pseudomonas aeruginosa. They share a unique chemical scaffold with a 4＇,5＇-enamide-3＇-deoxyuridine attached to DABA （N-methyl-2,3-diaminobutyryl） which was located in the peptide chain through peptide bond. In order to study the function of related genes and to employ synthetic biology to gain new SS derivatives, we obtained a complete SS biosynthetic gene cluster and heterologously expressed it in Streptomyces coelicolor Ml146, Ml152 and Ml154. Fermentation broth of the recombinant strains were detected using HPLC and HPLC-MS/MS, and the result showed that SS-A was successfully produced in the three strains, and its production level in S. coelicolor Ml154 was similar to the original wild type strain. In addition, a potential SS analogue named as SS-1154 was discovered from the fermentation broth of S. coelicolor M 1154.