Zhejiang University, College of Life Sciences, Hangzhou 310058, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China.
Hangzhou Huadong Medicine Group Biotechnology Institute Co., Ltd., Hangzhou 310011, China; Key Laboratory of Microbial Biochemistry and Metabolism Engineering of Zhejiang Province, Hangzhou 310058, China.
Gene. 2014 Jul 10;544(2):208-15. doi: 10.1016/j.gene.2014.04.044. Epub 2014 Apr 23.
Daptomycin, a novel cyclic lipopeptide antibiotic against Gram-positive bacteria, is produced by Streptomyces roseosporus. Though its biosynthetic mechanism, structural shuffling and fermentation optimization have been extensively studied, little is understood about its production regulation at the transcriptional levels. Here we reported that dptR2, encoding a DeoR-type regulator located close to the daptomycin biosynthesis gene cluster in S. roseosporus SW0702, is required for daptomycin production, but not for the expression of daptomycin gene cluster, suggesting that DptR2 was not a pathway-specific regulator. Furthermore, EMSA and qRT-PCR analysis suggested that DptR2 was positively auto-regulated by binding to its own promoter. Meanwhile, the binding sites on the dptR2 promoter were determined by a DNase I footprinting assay, and the essentiality of the inverted complementary sequences in the protected region for DptR2 binding was assessed. Our results for the first time reported the regulation of daptomycin production at the transcriptional level in S. roseosporus.
达托霉素是一种新型的环脂肽类抗生素，对革兰氏阳性菌具有活性，由玫瑰孢链霉菌产生。尽管其生物合成机制、结构改组和发酵优化已经得到了广泛的研究，但对其转录水平的生产调控知之甚少。在这里，我们报道了位于玫瑰孢链霉菌 SW0702 达托霉素生物合成基因簇附近的 dptR2 基因（编码一种 DeoR 型调控因子）对达托霉素的产生是必需的，但对达托霉素基因簇的表达不是必需的，这表明 DptR2 不是一种途径特异性的调控因子。此外，EMSA 和 qRT-PCR 分析表明，DptR2 通过结合自身启动子进行正调控。同时，通过 DNase I 足迹实验确定了 dptR2 启动子上的结合位点，并评估了保护区域内反向互补序列对 DptR2 结合的重要性。我们的研究结果首次报道了玫瑰孢链霉菌中达托霉素生产的转录水平调控。
