Perceiving environmental and internal information and reacting in adaptive ways are essential attributes of living organisms. Two-component systems are relevant protein machineries from prokaryotes and lower eukaryotes that enable cells to sense and process signals. Implicating sensory histidine kinases and response regulator proteins, both components take advantage of protein phosphorylation and flexibility to switch conformations in a signal-dependent way. Dozens of two-component systems act simultaneously in any given cell, challenging our understanding about the means that ensure proper connectivity. This review dives into the molecular level, attempting to summarize an emerging picture of how histidine kinases and cognate response regulators achieve required efficiency, specificity, and directionality of signaling pathways, properties that rely on protein:protein interactions. α helices that carry information through long distances, the fine combination of loose and specific kinase/regulator interactions, and malleable reaction centers built when the two components meet emerge as relevant universal principles.

中文翻译：

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两成分的传感和调节：组氨酸激酶如何在分子水平上与应答调节剂对话？

感知环境和内部信息并以适应性方式做出反应是生物体的基本属性。两组分系统是来自原核生物和低等真核生物的相关蛋白质机制，使细胞能够感知和处理信号。这两个成分都牵涉感觉组氨酸激酶和响应调节蛋白，它们利用蛋白磷酸化和灵活性来以信号依赖的方式转换构象。在任何给定的单元中，数十种两组分系统同时作用，这挑战了我们对确保正确连接的方法的理解。这篇评论深入探讨了分子水平，试图总结出有关组氨酸激酶和关联反应调节剂如何达到信号通路所需的效率，特异性和方向性的新图，依赖蛋白质：蛋白质相互作用的特性。通过长距离传递信息的α螺旋，松散的和特定的激酶/调节剂相互作用的精细结合以及当两个组分相遇时建立的可延展的反应中心便成为相关的通用原理。