Structure and Function of AmtR in Mycobacterium smegmatis: Implications for Post-Transcriptional Regulation of Urea Metabolism through a Small Antisense RNA.
Structure and Function of AmtR in Mycobacterium smegmatis: Implications for Post-Transcriptional Regulation of Urea Metabolism through a Small Antisense RNA.
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耻垢分枝杆菌中 AmtR 的结构和功能：通过小反义 RNA 对尿素代谢进行转录后调节的意义。
DOI：
10.1016/j.jmb.2016.09.009
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发表时间：
2016
影响因子：
5.6
通讯作者：
G. Cook
中科院分区：
文献类型：
--
作者：
M. Petridis;C. Vickers;Jennifer R Robson;J. McKenzie;Magdalena Bereza;Abigail V. Sharrock;H. Aung;V. Arcus;G. Cook
放线菌门土壤细菌普遍携带GlnR或AmtR作为氮代谢的全局调节因子，耻垢分枝杆菌（Mycobacteriumsmegmatis）同时具有这两种典型的调节因子，GlnR调节氮代谢关键基因的表达，AmtR的功能和信号转导途径在耻垢分枝杆菌（Mycobacteriumsmegmatis）中存在。smegmatis仍然在很大程度上未知。在这里，我们报告的结构和功能的M。smegmatisAmtR和描述的作用AmtR的调节氮代谢响应氮的可用性。目的：测定M.在smegabl中，我们进行了全基因组表达谱分析，比较了野生型与susan amtR突变体，并确定了11个基因表达的显著变化，包括一个参与尿素降解的操纵子。AmtR共识结合基序（CTGTC-N4-GACAG）被确定在该操纵子的启动子区域，并通过电泳迁移率变动分析和表面等离子体共振测量验证配体独立的，高亲和力的AmtR结合。我们证实了转录的acis编码的小RNA互补的基因编码的AmtR下氮过剩，我们提出了一个转录后的调节机制AmtR。AmtR在2.0 nm处的三维X射线结构显示了整体TetR样二聚体结构，并且M. smegmatis AmtR和谷氨酸棒杆菌AmtR调节结构域显示出较差的结构保守性，为缺乏M. smegmatisAmtR与腺苷酰化PII蛋白的相互作用。两者合计，我们的数据表明AmtR（阻遏物）/GlnR（激活剂）竞争性结合机制的转录调控尿素代谢，是由acis编码的小反义RNA控制。
Soil-dwelling bacteria of the phylum actinomycetes generally harbor either GlnR or AmtR as a global regulator of nitrogen metabolism.Mycobacteriumsmegmatisharbors both of these canonical regulators; GlnR regulates the expression of key genes involved in nitrogen metabolism, while the function and signal transduction pathway of AmtR inM. smegmatisremains largely unknown. Here, we report the structure and function of theM. smegmatisAmtR and describe the role of AmtR in the regulation of nitrogen metabolism in response to nitrogen availability. To determine the function of AmtR inM. smegmatis, we performed genome-wide expression profiling comparing the wild-typeversusan∆ amtRmutant and identified significant changes in the expression of 11 genes, including an operon involved in urea degradation. An AmtR consensus-binding motif (CTGTC-N4-GACAG) was identified in the promoter region of this operon, and ligand-independent, high-affinity AmtR binding was validated by both electrophoretic mobility shift assays and surface plasmon resonance measurements. We confirmed the transcription of acis-encoded small RNA complementary to the gene encoding AmtR under nitrogen excess, and we propose a post-transcriptional regulatory mechanism for AmtR. The three-dimensional X-ray structure of AmtR at 2.0 Å revealed an overall TetR-like dimeric structure, and the alignment of theM. smegmatisAmtR and Corynebacterium glutamicum AmtR regulatory domains showed poor structural conservation, providing a potential explanation for the lack ofM. smegmatisAmtR interaction with the adenylylated PIIprotein. Taken together, our data suggest an AmtR (repressor)/GlnR (activator) competitive binding mechanism for transcriptional regulation of urea metabolism that is controlled by acis-encoded small antisense RNA.
DOI：
10.1073/pnas.94.20.10955
发表时间：
1997-09-30
影响因子：
11.1
作者：
Pelicic, V;Jackson, M;Guilhot, C
通讯作者：
Guilhot, C
影响因子：
2.7
作者：
Hegde, P;Qi, R;Quackenbush, J
通讯作者：
Quackenbush, J
影响因子：
5.6
作者：
Yu, Zhou;Reichheld, Sean E.;Davidson, Alan R.
通讯作者：
Davidson, Alan R.