Genetic analysis, structural modeling, and direct coupling analysis suggest a mechanism for phosphate signaling in Escherichia coli.
Genetic analysis, structural modeling, and direct coupling analysis suggest a mechanism for phosphate signaling in Escherichia coli.
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DOI：
10.1186/1471-2156-16-s2-s2
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发表时间：
2015
期刊：
影响因子：
2.9
通讯作者：
McCleary WR
中科院分区：
文献类型：
--
作者：
Gardner SG;Miller JB;Dean T;Robinson T;Erickson M;Ridge PG;McCleary WR
适当的磷酸盐信号传导对于大肠杆菌和许多其他细菌的强劲生长至关重要。磷酸盐信号由 PhoR 和 PhoB 组成的经典双组分信号系统介导。 PhoR 组氨酸激酶负责磷酸化/去磷酸化反应调节因子 PhoB，后者控制在低磷酸盐条件下帮助生长的基因的表达。 PhoR 接收环境磷酸盐水平信号的机制仍然难以捉摸。由 PstS、PstC、PstA 和 PstB 蛋白以及负调节因子 PhoU 组成的转运蛋白复合物与将环境磷酸盐信号传导至 PhoR 有关。这项工作证实了 PhoU 和 PstSCAB 复合物对于高环境磷酸盐的正确信号传导是必需的。此外，我们还通过遗传分析鉴定了在 PhoU/PhoR 相互作用中重要的残基。使用蛋白质建模和对接方法，我们展示了一个相互作用模型，该模型指出了 PhoU 介导的向 PhoR 发出信号以改变其活性的潜在机制。该模型通过直接耦合分析进行测试。这些生物信息学工具与遗传和生化分析相结合，有助于识别和测试磷酸盐信号传导模型，并且可能适用于其他几种系统。
Proper phosphate signaling is essential for robust growth of Escherichia coli and many other bacteria. The phosphate signal is mediated by a classic two component signal system composed of PhoR and PhoB. The PhoR histidine kinase is responsible for phosphorylating/dephosphorylating the response regulator, PhoB, which controls the expression of genes that aid growth in low phosphate conditions. The mechanism by which PhoR receives a signal of environmental phosphate levels has remained elusive. A transporter complex composed of the PstS, PstC, PstA, and PstB proteins as well as a negative regulator, PhoU, have been implicated in signaling environmental phosphate to PhoR. This work confirms that PhoU and the PstSCAB complex are necessary for proper signaling of high environmental phosphate. Also, we identify residues important in PhoU/PhoR interaction with genetic analysis. Using protein modeling and docking methods, we show an interaction model that points to a potential mechanism for PhoU mediated signaling to PhoR to modify its activity. This model is tested with direct coupling analysis. These bioinformatics tools, in combination with genetic and biochemical analysis, help to identify and test a model for phosphate signaling and may be applicable to several other systems.