Expression of Shigella flexneri gluQ-rs gene is linked to dksA and controlled by a transcriptional terminator.
Expression of Shigella flexneri gluQ-rs gene is linked to dksA and controlled by a transcriptional terminator.
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Shigella flexneri gluq-rs基因的表达与DKSA相关，并由转录终结子控制。
DOI：
10.1186/1471-2180-12-226
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发表时间：
2012-10-05
期刊：
影响因子：
4.2
通讯作者：
Salazar JC
中科院分区：
文献类型：
--
作者：
Caballero VC;Toledo VP;Maturana C;Fisher CR;Payne SM;Salazar JC
谷氨酰队列-tRNAAsp 合成酶 (GluQ-RS) 是谷氨酰-tRNA 合成酶催化结构域的旁系同源物，可催化 tRNAAsp 摆动位置上谷氨酰队列的形成。在这里，我们分析了福氏志贺氏菌中其基因的转录，该基因位于 dksA 的下游，dksA 编码参与应激反应的转录调节因子。基因组结构 dksA-gluQ-rs 在 40 多种细菌物种中是保守的。 RT-PCR 分析显示，在福氏链霉生长过程中，两个基因均发生共转录，转录物水平没有显着变化。然而，基因间区域的 mRNA 水平在生长过程中发生变化，在稳定期增加，表明对 gluQ-rs 基因表达的额外控制水平。当构建体包含 dksA 启动子时，以 lacZ 作为报告基因的转录融合仅产生 β-半乳糖苷酶活性，表明 gluQ-rs 没有单独的启动子。利用生物信息学，我们鉴定了 dksA 和 gluQ-rs 之间的假定转录终止子。与含有野生型终止子序列的细胞相比，预测终止子的删除或改变导致 lacZ 报告基因的表达增加。对 gluQ-rs 突变体表型的分析表明，它可能在某些应激反应中发挥作用，因为渗透剂存在时突变体的生长受到损害。这里给出的结果表明 gluQ-rs 的表达依赖于 dksA 启动子，并强烈表明调节其表达的转录终止子的存在和功能。此外，结果还表明福氏志贺氏菌的谷氨酰-酮氨酸合成与应激反应之间存在联系。
Glutamyl queuosine-tRNAAsp synthetase (GluQ-RS) is a paralog of the catalytic domain of glutamyl-tRNA synthetase and catalyzes the formation of glutamyl-queuosine on the wobble position of tRNAAsp. Here we analyze the transcription of its gene in Shigella flexneri, where it is found downstream of dksA, which encodes a transcriptional regulator involved in stress responses. The genomic organization, dksA-gluQ-rs, is conserved in more than 40 bacterial species. RT-PCR assays show co-transcription of both genes without a significant change in transcript levels during growth of S. flexneri. However, mRNA levels of the intergenic region changed during growth, increasing at stationary phase, indicating an additional level of control over the expression of gluQ-rs gene. Transcriptional fusions with lacZ as a reporter gene only produced β-galactosidase activity when the constructs included the dksA promoter, indicating that gluQ-rs do not have a separate promoter. Using bioinformatics, we identified a putative transcriptional terminator between dksA and gluQ-rs. Deletion or alteration of the predicted terminator resulted in increased expression of the lacZ reporter compared with cells containing the wild type terminator sequence. Analysis of the phenotype of a gluQ-rs mutant suggested that it may play a role in some stress responses, since growth of the mutant was impaired in the presence of osmolytes. The results presented here, show that the expression of gluQ-rs depends on the dksA promoter, and strongly suggest the presence and the functionality of a transcriptional terminator regulating its expression. Also, the results indicate a link between glutamyl-queuosine synthesis and stress response in Shigella flexneri.
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DOI：
10.1073/pnas.0401982101
发表时间：
2004-05-18
影响因子：
11.1
作者：
Salazar, JC;Ambrogelly, A;Söll, D
通讯作者：
Söll, D
影响因子：
13.8
作者：
Kanehisa, M
通讯作者：
Kanehisa, M
影响因子：
2.1
作者：
BOOTH, IR;HIGGINS, CF
通讯作者：
HIGGINS, CF
DOI：
10.1073/pnas.120163297
发表时间：
2000-06-06
影响因子：
11.1
作者：
Datsenko, KA;Wanner, BL
通讯作者：
Wanner, BL
影响因子：
16
作者：
Navarre WW;Zou SB;Roy H;Xie JL;Savchenko A;Singer A;Edvokimova E;Prost LR;Kumar R;Ibba M;Fang FC
通讯作者：
Fang FC