PolY, a transcriptional regulator with ATPase activity, directly activates transcription of polR in polyoxin biosynthesis in Streptomyces cacaoi
PolY, a transcriptional regulator with ATPase activity, directly activates transcription of polR in polyoxin biosynthesis in Streptomyces cacaoi
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DOI：
10.1111/j.1365-2958.2009.06968.x
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发表时间：
2010-01-01
影响因子：
3.6
通讯作者：
Tan, Huarong
中科院分区：
文献类型：
--
作者：
Li, Rui;Liu, Gang;Tan, Huarong
对可可链霉菌多抗霉素生物合成簇中的转录调控基因polY进行了分析，其推导产物（PolY）与天蓝色链霉菌A3的AfsR具有氨基酸序列同源性（2）。PolY在其N端含有OmpR样DNA结合结构域，在蛋白质中间含有ATP酶结构域。多聚Y的破坏废除了多抗霉素的生物合成，这可以通过将单拷贝的多聚Y整合到破坏突变体的染色体中来恢复。polR是多氧霉素生物合成的一个途径特异性调控基因，其转录受polY调控。电泳迁移率变动分析和DNase I保护实验表明，PolY与polR的启动子区结合，结合位点含有链霉菌抗生素调控蛋白结合位点的典型核苷酸重复序列。聚Y在体外具有ATP酶活性。此外，ADP/ATP γ S与ATP酶结构域的结合引发了PolY的寡聚化，并增强了其DNA结合活性。进一步的体内实验表明，ADP/ATP浓度的变化显著影响细胞内PolY的活性。这些结果表明，ATP酶结构域可能是内源性ADP/ATP池的传感器，在生理条件下，ATP酶结构域的变化可调节PolY的活性。
polY, a transcriptional regulatory gene in the polyoxin biosynthetic cluster of Streptomyces cacaoi, was analysed, and its deduced product (PolY) showed amino acid sequence homology to AfsR from Streptomyces coelicolor A3(2). PolY contains an OmpR-like DNA binding domain at its N-terminal and an ATPase domain in the middle of the protein. Disruption of polY abolished polyoxin biosynthesis, which could be restored by the integration of a single copy of polY into the chromosome of the disruption mutant. Transcription of polR, a pathway-specific regulatory gene of polyoxin biosynthesis, was controlled by polY. Electrophoretic mobility shift assay and DNase I protection experiments indicated that PolY bound to the promoter region of polR, and the binding site contained a direct nucleotide repeat typical of Streptomyces antibiotic regulatory protein binding sites. PolY exhibited ATPase activity in vitro. Additionally, binding of ADP/ATP gamma S to ATPase domain triggered the oligomerization of PolY and enhanced its DNA binding activity. Consistently, further experiments in vivo demonstrated that changes of ADP/ATP concentrations significantly affected PolY activity in the cell. These results suggested that the ATPase domain might be a sensor of endogenous pool of ADP/ATP, whose change modulated PolY activity under the physiological conditions.