Identification of a quinone-sensitive redox switch in the ArcB sensor kinase
Identification of a quinone-sensitive redox switch in the ArcB sensor kinase
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DOI：
10.1073/pnas.0403064101
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发表时间：
2004-09-07
影响因子：
11.1
通讯作者：
Georgellis, D
中科院分区：
文献类型：
--
作者：
Malpica, R;Franco, B;Georgellis, D
大肠杆菌通过Arc双组分系统在其生长环境中感知和信号缺氧或低氧化还原条件。在厌氧条件下，arb传感器激酶自磷酸化和转磷酸化ArcA， ArcA是一种全局转录调节因子，控制许多参与呼吸或发酵代谢的操作子的表达。在有氧条件下，醌类电子载体作为直接负信号抑制ArcB的激酶活性。在这里，我们发现激酶沉默的分子机制涉及两个位于细胞质溶胶上的氧化还原活性半胱氨酸残基的氧化，这些残基参与分子间二硫键的形成，在这个反应中，醌提供了氧化能力的来源。因此，Arc信号转导通路中连接醌池氧化还原状态和转录装置的关键环节被阐明。
Escherichia coli senses and signals anoxic or low redox conditions in its growth environment by the Arc two-component system. Under anaerobic conditions, the ArcB sensor kinase autophosphorylates and transphosphorylates ArcA, a global transcriptional regulator that controls the expression of numerous operons involved in respiratory or fermentative metabolism. Under aerobic conditions, the kinase activity of ArcB is inhibited by the quinone electron carriers that act as direct negative signals. Here, we show that the molecular mechanism of kinase silencing involves the oxidation of two cytosol-located redox-active cysteine residues that participate in intermolecular disulfide bond formation, a reaction in which the quinones provide the source of oxidative power. Thus, a pivotal link in the Arc signal transduction pathway connecting the redox state of the quinone pool to the transcriptional apparatus is elucidated.