A key developmental regulator controls the synthesis of the antibiotic erythromycin in Saccharopolyspora erythraea
A key developmental regulator controls the synthesis of the antibiotic erythromycin in Saccharopolyspora erythraea
复制标题
DOI：
10.1073/pnas.0803622105
复制
发表时间：
2008-08-12
影响因子：
11.1
通讯作者：
Kao, Camilla M.
中科院分区：
文献类型：
--
作者：
Chng, Chinping;Lum, Amy M.;Kao, Camilla M.
红多孢菌生产红霉素，一种人类常用的抗生素。不寻常的是，红霉素生物合成（ery）簇缺乏一个途径特异性调控基因。我们分离了一个转录调节基因的ery生物合成从S。他们发现这种蛋白质似乎直接将即将到来的饥饿引起的形态变化与杀死其他细菌的分子的合成联系起来，红霉素DNA结合试验、液相和亲和层析、MALDI-MS分析和从头测序鉴定该蛋白（M-r = 18 kDa）为S. BldD是天蓝色链霉菌发育的关键调节因子，重组变异链球菌拟南芥BldD绑定到所有五个区域中的ery集群中的启动子，以及它自己的启动子，后者的数量级强于ery启动子。在S中缺失bldD。erythraea使液体培养物中的红霉素滴度降低7倍，并阻止固体培养基上的分化。此外，还对工业菌株S.红霉素滴度较高的红藻在红霉素合成过程中比野生型菌株表达更多的BldD。总之，这些结果表明，BldD同时调节红霉素的合成和形态分化。ery基因是待鉴定的受正调控的BldD直系同源物的第一个直接靶标。
Saccharopolyspora erythraea makes erythromycin, an antibiotic commonly used in human medicine. Unusually, the erythromycin biosynthetic (ery) cluster lacks a pathway-specific regulatory gene. We isolated a transcriptional regulator of the ery biosynthetic genes from S. erythraea and found that this protein appears to directly link morphological changes caused by impending starvation to the synthesis of a molecule that kills other bacteria, i.e., erythromycin. DNA binding assays, liquid and affinity chromatography, MALDI-MS analysis, and de novo sequencing identified this protein (M-r = 18 kDa) as the S. erythraea ortholog of BldD, a key regulator of development in Streptomyces coelicolor. Recombinant S. erythraea BldD bound to all five regions containing promoters in the ery cluster as well as to its own promoter, the latter with an order-of-magnitude stronger than to the ery promoters. Deletion of bldD in S. erythraea decreased the erythromycin titer in a liquid culture 7-fold and blocked differentiation on a solid medium. Moreover, an industrial strain of S. erythraea with a higher titer of erythromycin expressed more BldD than a wild-type strain during erythromycin synthesis. Together, these results suggest that BldD concurrently regulates the synthesis of erythromycin and morphological differentiation. The ery genes are the first direct targets of a BldD ortholog to be identified that are positively regulated.