Functional and structural characterization of bacterial blue-light sensitive photoreceptors

编码蓝光敏感光感受器的序列基序与其植物感受器具有很高的相似性，在许多原核生物基因组中都被鉴定出来。这种相似性也被发现在几种异源表达的基因产物中，这些基因产物显示出促黄体素典型的光谱反应。然而，除了相似之处，在光驱动动力学上也发现了显著的差异。与植物原核生物相比，原核生物促红细胞生成素相关蛋白更倾向于全长表达。这使得对光诱导信号转导的研究成为可能，因为这些受体中的许多除了发色团结合基序外，还在其C-末端部分携带一个组氨酸激动域，该结构域与类似的Chey-like反应调节器相互作用，使它们成为蓝光驱动的细菌双组分信号转导系统的新成员。我们已经描述了芽孢杆菌蛋白YtwA的光谱性质，然而，对更精确的分析有强烈的需求，包括突变的产生和对其在同源系统中的行为的研究。利用蛋白质结晶进行结构测定的实验已经启动。

Sequence motifs encoding blue-light sensitive photoreceptors with high similarity to their plant counterparts have been identified in many prokaryote genomes. This resemblance was found also for several heterologously expressed gene products that show the phototropin-typical spectroscopic reactions. However, besides similarities, significant differences in the light-driven kinetics were detected. In contrast to the plant protomers, the prokaryote phototropin-related proteins are more prone to full-length expression. This allows an access to the study of the light induced signal transduction, since many of these receptors carry - besides the chromophore-binding motif - a histidine kinase domain in their C-terminal part that interacts with similarly present CheY-like response regulators, making them new members of a blue light-driven bacterial two-component signal transduction system. The spectroscopic properties of the Bacillus protein YtvA have already been described by us, however, there is strong demand for a more precise analysis, including the generation of mutants and a study of its behavior in the homologous system. Structure determination experiments by protein crystallization have been initiated.