CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
Mar Drugs. 2019 Sep 29;17(10):560. doi: 10.3390/md17100560.
Atratumycin is a cyclodepsipeptide with activity against isolated from deep-sea derived SCSIO ZH16NS-80S. Analysis of the atratumycin biosynthetic gene cluster () revealed that its biosynthesis is regulated by multiple factors, including two LuxR regulatory genes ( and ), two ABC transporter genes ( and ) and one antibiotic regulatory gene (). In this work, three regulatory and two transporter genes were unambiguously determined to provide positive, negative and self-protective roles during biosynthesis of atratumycin through bioinformatic analyses, gene inactivations and -complementation studies. Notably, an unusual antibiotic regulatory protein Atr32 was characterized as a negative regulator; the function of Atr32 is distinct from previous studies. Five over-expression mutant strains were constructed by rational application of the regulatory and transporter genes; the resulting strains produced significantly improved titers of atratumycin that were ca. 1.7-2.3 fold greater than wild-type (WT) producer. Furthermore, the atratumycin gene cluster was successfully expressed in M1154, thus paving the way for the transfer and recombination of large DNA fragments. Overall, this finding sets the stage for understanding the unique biosynthesis of pharmaceutically important atratumycin and lays the foundation for generating anti-tuberculosis lead compounds possessing novel structures.
阿特拉霉素是一种环二肽抗生素，具有抗药性，从深海来源的 SCSIO ZH16NS-80S 中分离得到。对阿特拉霉素生物合成基因簇的分析表明，其生物合成受到多种因素的调节，包括两个 LuxR 调节基因（和）、两个 ABC 转运体基因（和）和一个抗生素调节基因（）。在这项工作中，通过生物信息学分析、基因失活和互补研究，明确了三个调节基因和两个转运体基因在阿特拉霉素生物合成过程中分别具有正、负和自我保护作用。值得注意的是，一种不寻常的抗生素调节蛋白 Atr32 被鉴定为负调节因子；Atr32 的功能与以前的研究不同。通过合理应用调节基因和转运体基因，构建了五个过表达突变株；所得菌株产生的阿特拉霉素产量显著提高，约为野生型（WT）产生菌的 1.7-2.3 倍。此外，阿特拉霉素基因簇在 M1154 中成功表达，从而为大 DNA 片段的转移和重组铺平了道路。总的来说，这一发现为理解具有重要药用价值的阿特拉霉素的独特生物合成奠定了基础，并为生成具有新型结构的抗结核先导化合物奠定了基础。
