Overexpression of the diguanylate cyclase CdgD blocks developmental transitions and antibiotic biosynthesis in Streptomyces coelicolor
Overexpression of the diguanylate cyclase CdgD blocks developmental transitions and antibiotic biosynthesis in Streptomyces coelicolor
复制标题
二鸟苷酸环化酶 CdgD 的过度表达会阻碍天蓝色链霉菌的发育转变和抗生素生物合成
DOI：
10.1007/s11427-019-9549-8
复制
发表时间：
2019-11-01
影响因子：
9.1
通讯作者：
Lu, Yinhua
中科院分区：
文献类型：
--
作者：
Liu, Xiaocao;Zheng, Guosong;Lu, Yinhua
环状二聚体 GMP (c-di-GMP) 已成为调节高 GC 革兰氏阳性链霉菌发育和抗生素生产的核苷酸第二信使。在此，通过遗传和生化分析，对来自模型菌株天蓝色链霉菌的 SCO5345 编码的二鸟苷酸环化酶 (DGC) CdgD 进行了功能鉴定和表征，认为其参与 c-di-GMP 合成。 cdgD 过表达导致放线菌紫素和十一烷基灵菌红素的产量显着减少，并完全阻止两种不同固体培养基上的孢子形成或气生菌丝体形成。在cdgD过表达菌株中，细胞内c-di-GMP水平比野生型菌株高13-27倍。体外酶测定表明，CdgD 作为 DGC，可以有效催化两个 GTP 分子合成 c-di-GMP。两种工业链霉菌菌株中 cdgD 的异源过量生产同样可能损害发育转变以及抗生素生物合成。总的来说，我们的结果与之前报道的数据相结合清楚地表明，c-di-GMP 介导的信号通路在链霉菌的生命周期以及次级代谢中发挥着核心和普遍的作用。
Cyclic dimeric GMP (c-di-GMP) has emerged as the nucleotide second messenger regulating both development and antibiotic production in high-GC, Gram-positive streptomycetes. Here, a diguanylate cyclase (DGC), CdgD, encoded by SCO5345 from the model strain Streptomyces coelicolor, was functionally identified and characterized to be involved in c-di-GMP synthesis through genetic and biochemical analysis. cdgD overexpression resulted in significantly reduced production of actinorhodin and undecylprodigiosin, as well as completely blocked sporulation or aerial mycelium formation on two different solid media. In the cdgD-overexpression strain, intracellular c-di-GMP levels were 13-27-fold higher than those in the wild-type strain. In vitro enzymatic assay demonstrated that CdgD acts as a DGC, which could efficiently catalyze the synthesis of c-di-GMP from two GTP molecules. Heterologous overproduction of cdgD in two industrial Streptomyces strains could similarly impair developmental transitions as well as antibiotic biosynthesis. Collectively, our results combined with previously reported data clearly demonstrated that c-di-GMP-mediated signalling pathway plays a central and universal role in the life cycle as well as secondary metabolism in streptomycetes.