Light-Induced Conformational Changes of LOV2-Kinase and the Linker Region in Arabidopsis Phototropin2
Light-Induced Conformational Changes of LOV2-Kinase and the Linker Region in Arabidopsis Phototropin2
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拟南芥趋光素 2 中 LOV2 激酶和连接区的光诱导构象变化
DOI：
10.1021/acs.jpcb.7b01552
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Terazima Masahide
中科院分区：
文献类型：
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作者：
Takakado Akira;Nakasone Yusuke;Okajima Koji;Tokutomi Satoru;Terazima Masahide
向光蛋白（phototropins，phots）是一种存在于多种高等植物和藻类中的蓝光感受器。自发现以来，这类蛋白质的光化学反应就引起了人们的广泛关注。Phots有两个光传感器域，称为光氧电压1（LOV 1）和LOV 2。LOV结构域的特征性加合物形成后，LOV 2结构域的C-末端区域发生构象变化，表征这种变化对于理解生物学功能，即激酶活化是重要的。本文研究了Jα-螺旋及其邻近延伸区（连接体）的反应动力学。接头部分和Jα-螺旋的构象被发现以双态方式显著改变。此外，激酶结构域的构象变化也被成功地检测为翻译扩散的变化，尽管由于激酶结构域运动的CD强度几乎是沉默的。这些观察结果表明激酶结构域的三级结构发生了变化。激酶结构域变化的速率几乎与LOV 2-接头的变化速率相同，表明接头的构象变化是激酶活化的速率决定步骤。
Phototropins (phots) are blue light sensors found in a variety of higher plants and algae. The photochemical reactions of this family of proteins have attracted much attention since their discovery. Phots have two light sensor domains called light-oxygen-voltage 1 (LOV1) and LOV2. After the formation of the characteristic adduct of the LOV domain, a conformational change of the C-terminal region of the LOV2 domain occurs, and characterizing this change is important for understanding biological function, that is, kinase activation. Here, the reaction dynamics of the Jα-helix and the extended region adjacent to the Jα-helix (connector) have been investigated. The conformation of the connector part and the Jα-helix were found to alter significantly in a two-state manner. Furthermore, the conformational change of the kinase domain was also successfully detected as a change in translational diffusion, although the CD intensity due to the kinase domain movement was almost silent. These observations indicate that the tertiary structure of the kinase domain changes. The rate of the kinase domain change is almost the same as that of the change for the LOV2-linker, suggesting that the conformational change of the linker is the rate-determining step for kinase activation.