Computational and experimental analyses reveal the essential roles of interdomain linkers in the biological function of chemotaxis histidine kinase CheA.
Computational and experimental analyses reveal the essential roles of interdomain linkers in the biological function of chemotaxis histidine kinase CheA.
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DOI：
10.1021/ja3056694
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发表时间：
2012-10-03
影响因子：
15
通讯作者：
Dahlquist, Frederick W.
中科院分区：
文献类型：
--
作者：
Wang, Xiqing;Wu, Chun;Anh Vu, Joan-Emma Shea;Dahlquist, Frederick W.
细菌趋化性是一种双组分信号转导途径，这种趋化性使细菌能够调节其游泳行为以响应环境刺激。二聚体五结构域组氨酸激酶CheA在该途径中起着核心作用，通过P1和P4结构域之间的反式自磷酸化将感觉信号转化为化学信号。这种自磷酸化通过CheA、CheW和化学受体的P5结构域之间的网络相互作用来调节。尽管有丰富的结构信息，这些组件和它们的相互作用，催化P4结构域的激酶活性是如何调节的信号从监管P5结构域的关键问题仍然知之甚少。我们进行了复制交换分子动力学模拟的CheA激酶的核心，并发现，虽然个别域保持其结构的折叠，这些域表现出各种域间的方向，由于两个域间连接。采用结构域间排列的部分填充构象适合于构建功能性三元复合物。从这个结构模型衍生的变构网络意味着两个链接在CheA的活动中的关键作用。通过一系列生化和遗传测定来分配这些接头的生化和生物学功能，这些测定表明P4-P5接头控制CheA的激活，而P3-P4接头控制基础自磷酸化活性和CheA的激活。这些结果揭示了两个连接子之间的功能依赖性和连接子在将信号信息从一个结构域传递到另一个结构域中的重要作用。
A two-component signal transduction pathway underlies the phenomenon of bacterial chemotaxis that allows bacteria to modulate their swimming behavior in response to environmental stimuli. The dimeric five-domain histidine kinase, CheA, plays a central role in the pathway, converting sensory signals to a chemical signal via trans-autophosphorylation between the P1 and P4 domains. This autophosphorylation is regulated via the networked interactions among the P5 domain of CheA, CheW, and chemoreceptors. Despite a wealth of structural information about these components and their interactions, the key question of how the kinase activity of the catalytic P4 domain is regulated by the signal received from the regulatory P5 domain remains poorly understood. We performed replica exchange molecular dynamics simulations on the CheA kinase core and found that while individual domains maintained their structural fold, these domains exhibited a variety of inter-domain orientations due to two interdomain linkers. A partially populated conformation that adopts an inter-domain arrangement is suitable for building a functional ternary complex. An allosteric network derived from this structural model implies critical roles for two linkers in CheA’s activity. The biochemical and biological functions of these linkers were assigned via a series of biochemical and genetic assays that show the P4–P5 linker controls the activation of CheA and the P3–P4 linker controls both the basal autophosphorylation activity and the activation of CheA. These results reveal the functional dependence between the two linkers and the essential role of the linkers in passing signal information from one domain to another.
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影响因子：
64.5
作者：
Bilwes, AM;Alex, LA;Simon, MI
通讯作者：
Simon, MI
影响因子：
3.6
作者：
SWANSON, RV;BOURRET, RB;SIMON, MI
通讯作者：
SIMON, MI
影响因子：
2.9
作者：
Gloor, Susan L.;Falke, Joseph J.
通讯作者：
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DOI：
10.1073/pnas.1115719109
发表时间：
2012-03-06
影响因子：
11.1
作者：
Briegel, Ariane;Li, Xiaoxiao;Crane, Brian R.
通讯作者：
Crane, Brian R.
DOI：
10.1073/pnas.86.4.1208
发表时间：
1989-02-01
影响因子：
11.1
作者：
BORKOVICH, KA;KAPLAN, N;SIMON, MI
通讯作者：
SIMON, MI