Production of secondary metabolites is tightly regulated by transcriptional regulators in Streptomyces. Many regulators have been identified by gene disruption in Streptomyces; however, there are still unknown regulatory genes yet to be revealed due to gene silence under laboratory culture conditions. In present study, a T7 expression system was used to identify novel regulators by gene deletion and constitutive-expression of nine candidates. We reported that the constitutive-expression of a MarR family transcriptional regulator MapR (SCO2398) resulted in increase of actinorhodin (ACT) production. The expression profiling indicated that MapR regulates ACT production through a transcriptional cascade. Collectively, our study suggests that MapR serves as a novel positive regulator of ACT production.

中文翻译：

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MarR 家族转录因子 MapR 正向调节天蓝色链霉菌中放线菌素的产生。

次级代谢产物的产生受到链霉菌中转录调节因子的严格调控。链霉菌中的基因破坏已鉴定出许多调节因子; 然而，由于实验室培养条件下的基因沉默，仍有未知的调控基因有待揭示。在本研究中，T7 表达系统用于通过基因缺失和九个候选者的组成型表达来鉴定新的调节因子。我们报道了 MarR 家族转录调节因子 MapR (SCO2398) 的组成型表达导致放线菌素 (ACT) 产量增加。表达谱表明 MapR 通过转录级联调节 ACT 的产生。总的来说，我们的研究表明 MapR 可作为 ACT 生产的新型正调节器。