Systems-Wide Dissection of Organic Acid Assimilation in Pseudomonas aeruginosa Reveals a Novel Path To Underground Metabolism.
Systems-Wide Dissection of Organic Acid Assimilation in Pseudomonas aeruginosa Reveals a Novel Path To Underground Metabolism.
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作者：
铜绿假单胞菌是引起医院感染最常见、最严重的病原菌之一。这种细菌也是囊性纤维化患者呼吸道感染的主要原因。PA具有显著的代谢可塑性，使其能够在不同的环境条件和生态位下茁壮成长；然而，人们对感染期间维持其生长的中心代谢途径或这些途径的确切运作方式知之甚少。在这项工作中，我们使用组学方法(转录组学、蛋白质组学、代谢组学和13C-FLUX组学)和反向遗传学相结合的方法来提供系统水平的了解，以了解感染相关的有机酸琥珀酸和丙酸是如何被PA代谢的。此外，通过对2-甲基柠檬酸合成酶(2-MCS；PrPC)及其类似物柠檬酸(CIT)合成酶(GLTA)的结构和动力学分析，我们展示了这两个关键的酶步骤在PA有机酸同化过程中是如何相互联系的。我们发现，PA可以通过获得转录抑制因子的突变来快速适应GLTA功能的丧失，然后转录抑制因子下调PrPC的表达。我们的发现提供了一个清楚的例子，说明在酶底物杂乱的促进下，“地下新陈代谢”如何“重新连接”PA新陈代谢，使其能够克服一种关键酶的损失。这种病原体特有的知识对于以模型为驱动的框架以靶向细菌中心代谢的进展至关重要。
The human pathogen Pseudomonas aeruginosa (Pa) is one of the most frequent and severe causes of nosocomial infection. This organism is also a major cause of airway infections in people with cystic fibrosis (CF). Pa is known to have a remarkable metabolic plasticity, allowing it to thrive under diverse environmental conditions and ecological niches; yet, little is known about the central metabolic pathways that sustain its growth during infection or precisely how these pathways operate. In this work, we used a combination of ‘omics approaches (transcriptomics, proteomics, metabolomics, and 13C-fluxomics) and reverse genetics to provide systems-level insight into how the infection-relevant organic acids succinate and propionate are metabolized by Pa. Moreover, through structural and kinetic analysis of the 2-methylcitrate synthase (2-MCS; PrpC) and its paralogue citrate (CIT) synthase (GltA), we show how these two crucial enzymatic steps are interconnected in Pa organic acid assimilation. We found that Pa can rapidly adapt to the loss of GltA function by acquiring mutations in a transcriptional repressor, which then derepresses prpC expression. Our findings provide a clear example of how “underground metabolism,” facilitated by enzyme substrate promiscuity, “rewires” Pa metabolism, allowing it to overcome the loss of a crucial enzyme. This pathogen-specific knowledge is critical for the advancement of a model-driven framework to target bacterial central metabolism.
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DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
DOI：
10.1111/j.2517-6161.1995.tb02031.x
发表时间：
1995-01-01
影响因子：
5.8
作者：
BENJAMINI, Y;HOCHBERG, Y
通讯作者：
HOCHBERG, Y
影响因子：
6.7
作者：
Flynn, Jeffrey M.;Niccum, David;Hunter, Ryan C.
通讯作者：
Hunter, Ryan C.
DOI：
10.1111/j.1432-1033.2004.04255.x
发表时间：
2004-08-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
Brock, M;Buckel, W
通讯作者：
Buckel, W
DOI：
10.1046/j.1432-1327.2001.02262.x
发表时间：
2001-06-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
Brock, M;Darley, D;Buckel, W
通讯作者：
Buckel, W