Response regulators function as the output components of two-component systems, which couple the sensing of environmental stimuli to adaptive responses. Response regulators typically contain conserved receiver (REC) domains that function as phosphorylation-regulated switches to control the activities of effector domains that elicit output responses. This modular design is extremely versatile, enabling different regulatory strategies tuned to the needs of individual signaling systems. This review summarizes structural features that underlie response regulator function. An abundance of atomic resolution structures and complementary biochemical data have defined the mechanisms for response regulator enzymatic activities, revealed trends in regulatory strategies utilized by response regulators of different subfamilies, and provided insights into interactions of response regulators with their cognate histidine kinases. Among the hundreds of thousands of response regulators identified, variations abound. This article provides a framework for understanding structural features that enable function of canonical response regulators and a basis for distinguishing noncanonical configurations.

中文翻译：

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响应调节器功能的结构基础。

响应调节器充当两组分系统的输出组分，将环境刺激感测与自适应响应耦合在一起。响应调节剂通常包含保守的受体（REC）域，其充当磷酸化调节开关，以控制引起输出响应的效应子域的活动。这种模块化设计非常灵活，可以根据个人信号系统的需求调整不同的监管策略。这篇综述总结了响应调节器功能的基础结构特征。大量的原子拆分结构和互补的生化数据确定了应答调节酶活性的机制，揭示了不同亚家族的应答调节剂利用的调节策略的趋势，并提供了对反应调节剂与其同源组氨酸激酶相互作用的见解。在成千上万的响应调节器中，变化很大。本文提供了一个框架，用于理解启用规范响应调节器功能的结构特征，以及区分非规范配置的基础。