Chromophore conformation and the evolution of tertiary structural changes in photoactive yellow protein
Chromophore conformation and the evolution of tertiary structural changes in photoactive yellow protein
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DOI：
10.1016/j.str.2004.04.008
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发表时间：
2004-06-01
期刊：
影响因子：
5.7
通讯作者：
Moffat, K
中科院分区：
文献类型：
--
作者：
Anderson, S;Srajer, V;Moffat, K
我们使用时间分辨晶体学来观察细菌蓝光光感受器在其整个光周期中的结构进展。收集光活性黄蛋白E46 Q突变体光活化后10 ns至100 ms的数据。瞬态发色团构象的精细化表明，光谱上不同的中间体形成通过逐步破坏的氢键网络的发色团。尽管结构变化发生在发色团上和周围的几纳秒内，但三级结构变化的独特模式需要几毫秒才能完全通过整个分子，从而产生推定的信号状态。值得注意的是，发色团构象和这种小蛋白质的三级结构之间的耦合并不紧密：发色团构象和蛋白质三级结构之间的变化存在超前和滞后。
We use time-resolved crystallography to observe the structural progression of a bacterial blue light photoreceptor throughout its photocycle. Data were collected from 10 ns to 100 ms after photoactivation of the E46Q mutant of photoactive yellow protein. Refinement of transient chromophore conformations shows that the spectroscopically distinct intermediates are formed via progressive disruption of the hydrogen bond network to the chromophore. Although structural change occurs within a few nanoseconds on and around the chromophore, it takes milliseconds for a distinct pattern of tertiary structural change to fully progress through the entire molecule, thus generating the putative signaling state. Remarkably, the coupling between the chromophore conformation and the tertiary structure of this small protein is not tight: there are leads and lags between changes in the conformation of the chromophore and the protein tertiary structure.