SIGNAL TRANSDUCTION IN BACTERIA - CHEW FORMS A REVERSIBLE COMPLEX WITH THE PROTEIN-KINASE CHEA
SIGNAL TRANSDUCTION IN BACTERIA - CHEW FORMS A REVERSIBLE COMPLEX WITH THE PROTEIN-KINASE CHEA
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DOI：
10.1073/pnas.88.3.750
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发表时间：
1991-02-01
影响因子：
11.1
通讯作者：
DAHLQUIST, FW
中科院分区：
文献类型：
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作者：
GEGNER, JA;DAHLQUIST, FW
在大肠杆菌的信号转导途径中的一个重要步骤是通过趋化性受体蛋白来控制CheA的蛋白激酶活性。这种控制需要Chew蛋白的参与。虽然受体和激酶之间偶联的生物化学性质尚不清楚，但很可能CheW与受体和CheA相互作用。在这次交流中，我们报告直接测量的物理相互作用之间的咀嚼和CheA。我们利用平衡柱色谱法的Hummel和Dreyer表明，CheW和CheA表现出可逆的结合与化学计量的两个CheW单体每个CheA二聚体。CheW被发现存在的单体和CheA被发现存在的二聚体的平衡分析超离心。CheW-CheA相互作用的解离常数（在160 mM KCl/5 mM MgCl 2中，pH 7.4，4 ℃）被确定为在17 μ M的生理相关范围内。没有证据表明协同性协会的咀嚼与CheA被发现。
An essential step in the signal transduction pathway of Escherichia coli is the control of the protein kinase activity of CheA by the chemotaxis receptor proteins. This control requires the participation of the CheW protein. Although the biochemical nature of the coupling between the receptors and the kinase is unknown, it is likely that CheW interacts with the receptors and with CheA. In this communication, we report direct measurement of a physical interaction between CheW and CheA. We utilized the equilibrium column chromatography method of Hummel and Dreyer to show that CheW and CheA exhibit reversible binding with the stoichiometry of two CheW monomers per CheA dimer. CheW was found to exist as monomers and CheA was found to exist as dimers by equilibrium analytical ultracentrifugation. The dissociation constant for the CheW-CheA interaction (in 160 mM KCl/5 mM MgCl2, pH 7.4 at 4-degrees-C) was determined to be in the physiologically relevant range of 17-mu-M. No evidence for cooperativity in the association of CheW with CheA was found.