Velázquez Escobar Francisco, Buhrke David, Fernandez Lopez Maria, Shenkutie Sintayehu Manaye, von Horsten Silke, Essen Lars-Oliver, Hughes Jon, Hildebrandt Peter
Institut für Chemie, Technische Universität Berlin, Germany.
Plant Physiology, Justus-Liebig University Gießen, Giessen, Germany.
FEBS Lett. 2017 May;591(9):1258-1265. doi: 10.1002/1873-3468.12642. Epub 2017 Apr 16.
The N-terminal extension (NTE) of plant phytochromes has been suggested to play a functional role in signaling photoinduced structural changes. Here, we use resonance Raman spectroscopy to study the effect of the NTE on the chromophore structure of B-type phytochromes from two evolutionarily distant plants. NTE deletion seems to have no effect on the chromophore in the inactive Pr state, but alters the torsion of the C-D ring methine bridge and the surrounding hydrogen bonding network in the physiologically active Pfr state. These changes are accompanied by a shift of the conformational equilibrium between two Pfr substates, which might affect the thermal isomerization rate of the C-D double bond and, thus, account for the effect of the NTE on the dark reversion kinetics.
植物光敏色素的N端延伸（NTE）被认为在光诱导结构变化的信号传导中发挥功能作用。在这里，我们使用共振拉曼光谱来研究NTE对来自两种进化距离较远植物的B型光敏色素发色团结构的影响。NTE缺失似乎对非活性Pr状态下的发色团没有影响，但会改变生理活性Pfr状态下C-D环次甲基桥的扭转以及周围的氢键网络。这些变化伴随着两个Pfr亚状态之间构象平衡的移动，这可能会影响C-D双键的热异构化速率，从而解释NTE对暗逆转动力学的影响。
