The Streptococcus mutans GlnR protein exhibits an increased affinity for the glnRA operon promoter when bound to GlnK
The Streptococcus mutans GlnR protein exhibits an increased affinity for the glnRA operon promoter when bound to GlnK
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DOI：
10.1590/s0100-879x2011007500138
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发表时间：
2011-12-01
影响因子：
2.3
通讯作者：
Benelli, E.M.
中科院分区：
文献类型：
--
作者：
Castellen, P.;Rego, F.G.M.;Benelli, E.M.
对致病性革兰氏阳性菌氮代谢的控制已经在多种物种中进行了研究，并与毒力因子的表达有关。到目前为止，还没有关于牙科致病物种变形链球菌氮代谢的数据报道。GlnR控制相关细菌枯草芽孢杆菌的氮同化作用，在变形链球菌中对其DNA和蛋白质结合活性进行了评估。变形链球菌GlnR蛋白的电泳迁移率改变分析表明，GlnR结合于glnRA和amtB-glnK操纵子的启动子区域。交联和下拉分析表明，GlnR与GlnK相互作用，GlnK是一种协调氮代谢调节的信号转导蛋白。在形成这个稳定的复合体后，GlnK增强了GlnR对glnRA操纵子启动子的亲和力。这些结果支持GlnR参与氮代谢相关基因的转录调控，并表明GlnK向GlnR传递有关铵可利用性的信息。
The control of nitrogen metabolism in pathogenic Gram-positive bacteria has been studied in a variety of species and is involved with the expression of virulence factors. To date, no data have been reported regarding nitrogen metabolism in the odontopathogenic species Streptococcus mutans. GlnR, which controls nitrogen assimilation in the related bacterial species, Bacillus subtilis, was assessed in S. mutans for its DNA and protein binding activity. Electrophoretic mobility shift assay of the S. mutans GlnR protein indicated that GlnR binds to promoter regions of the glnRA and amtB-glnK operons. Cross-linking and pull-down assays demonstrated that GlnR interacts with GlnK, a signal transduction protein that coordinates the regulation of nitrogen metabolism. Upon formation of this stable complex, GlnK enhances the affinity of GlnR for the glnRA operon promoter. These results support an involvement of GlnR in transcriptional regulation of nitrogen metabolism-related genes and indicate that GlnK relays information regarding ammonium availability to GlnR.