Photosynthetic reaction centres harvest the energy content of sunlight by transporting electrons across an energy-transducing biological membrane. Here we use time-resolved serial femtosecond crystallography 1 using an X-ray free-electron laser 2 to observe light-induced structural changes in the photosynthetic reaction centre of Blastochloris viridis on a timescale of picoseconds. Structural perturbations first occur at the special pair of chlorophyll molecules of the photosynthetic reaction centre that are photo-oxidized by light. Electron transfer to the menaquinone acceptor on the opposite side of the membrane induces a movement of this cofactor together with lower amplitude protein rearrangements. These observations reveal how proteins use conformational dynamics to stabilize the charge-separation steps of electron-transfer reactions. Time-resolved serial femtosecond crystallography is used to reveal the structural changes that stabilize the charge-separation steps of electron-transfer reactions in the photosynthetic reaction centre of Blastochloris viridis on a timescale of picoseconds.

中文翻译：

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光合反应中心内的超快结构变化

光合反应中心通过将电子传输穿过能量转换生物膜来收集阳光的能量。在这里，我们使用时间分辨连续飞秒晶体学 1 使用 X 射线自由电子激光器 2 在皮秒时间尺度上观察 Blastochloris viridis 光合反应中心的光诱导结构变化。结构扰动首先发生在被光光氧化的光合反应中心的特殊叶绿素分子对上。电子转移到膜另一侧的甲基萘醌受体会引起该辅因子的运动以及较低幅度的蛋白质重排。这些观察揭示了蛋白质如何利用构象动力学来稳定电子转移反应的电荷分离步骤。