Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, León, Spain.
PLoS One. 2012;7(3):e32697. doi: 10.1371/journal.pone.0032697. Epub 2012 Mar 5.
ArgR is the regulator of arginine biosynthesis genes in Streptomyces species. Transcriptomic comparison by microarrays has been made between Streptomyces coelicolor M145 and its mutant S. coelicolor ΔargR under control, unsupplemented conditions, and in the presence of arginine. Expression of 459 genes was different in transcriptomic assays, but only 27 genes were affected by arginine supplementation. Arginine and pyrimidine biosynthesis genes were derepressed by the lack of ArgR, while no strong effect on expression resulted on arginine supplementation. Several nitrogen metabolism genes expression as glnK, glnA and glnII, were downregulated in S. coelicolor ΔargR. In addition, downregulation of genes for the yellow type I polyketide CPK antibiotic and for the antibiotic regulatory genes afsS and scbR was observed. The transcriptomic data were validated by either reverse transcription-PCR, expression of the gene-promoter coupled to the luciferase gene, proteomic or by electrophoresis mobility shift assay (EMSA) using pure Strep-tagged ArgR. Two ARG-boxes in the arginine operon genes suggest that these genes are more tightly controlled. Other genes, including genes encoding regulatory proteins, possess a DNA sequence formed by a single ARG-box which responds to ArgR, as validated by EMSA.
ArgR 是链霉菌属中精氨酸生物合成基因的调节因子。通过微阵列进行转录组比较，在对照、未补充条件下以及存在精氨酸的情况下，比较了链霉菌属 M145 和其突变体 S. coelicolor ΔargR。在转录组分析中，有 459 个基因的表达不同，但只有 27 个基因受到精氨酸补充的影响。精氨酸和嘧啶生物合成基因因缺乏 ArgR 而被去阻遏，而精氨酸补充对表达没有强烈影响。一些氮代谢基因的表达，如 glnK、glnA 和 glnII，在 S. coelicolor ΔargR 中下调。此外，还观察到黄色 I 型聚酮 CPK 抗生素和抗生素调节基因 afsS 和 scbR 的基因下调。通过逆转录-PCR、与荧光素酶基因偶联的基因表达、蛋白质组学或使用纯 Strep 标记的 ArgR 进行电泳迁移率变动分析 (EMSA) 验证了转录组数据。精氨酸操纵子基因中的两个 ARG 框表明这些基因受到更严格的控制。其他基因，包括编码调节蛋白的基因，具有由单个 ARG 框组成的 DNA 序列，该序列响应 ArgR，如 EMSA 验证的那样。
