A molecular movie at 1.8 Å resolution displays the photocycle of photoactive yellow protein, a eubacterial blue-light receptor, from nanoseconds to seconds
A molecular movie at 1.8 Å resolution displays the photocycle of photoactive yellow protein, a eubacterial blue-light receptor, from nanoseconds to seconds
复制标题
DOI：
10.1021/bi0107142
复制
发表时间：
2001-11-20
期刊：
影响因子：
2.9
通讯作者：
Moffat, K
中科院分区：
文献类型：
--
作者：
Ren, Z;Perman, B;Moffat, K
细菌的蓝光感光器，光敏黄蛋白，光周期的刺激由7纳秒的激光脉冲照射单晶。分子事件被记录在高分辨率的时间分辨X射线劳厄衍射，因为它们演变在真实的时间，从1纳秒到秒后的激光脉冲。在环境温度下的光循环过程中的复杂的结构变化显示在电影的差异电子密度图相对于黑暗状态。进入光循环的关键步骤被确定为翻转的4-羟基肉桂酸发色团的羰基到相邻的，疏水的环境，而不是伴随的异构化发色团尾部的双键。在发色团产生的结构扰动传播整个蛋白质作为光诱导的“蛋白质地震”，其“震中”在发色团的羰基部分。
The photocycle of the bacterial blue-light photoreceptor, photoactive yellow protein, was stimulated by illumination of single crystals by a 7 ns laser pulse. The molecular events were recorded at high resolution by time-resolved X-ray Laue diffraction as they evolved in real time, from I ns to seconds after the laser pulse. The complex structural changes during the photocycle at ambient temperature are displayed in a movie of difference electron density maps relative to the dark state. The step critical to entry into the photocycle is identified as flipping of the carbonyl group of the 4-hydroxycinnamic acid chromophore into an adjacent, hydrophobic environment rather than the concomitant isomerization about the double bond of the chromophore tail. The structural perturbation generated at the chromophore propagates throughout the entire protein as a light-induced "protein quake" with its "epicenter" at the carbonyl moiety of the chromophore.