In plants and green algae, light-harvesting complexes (LHCs) are a large family of chlorophyll binding proteins functioning as antennae, collecting solar photons and transferring the absorbed energy to the photosynthetic reaction centers, where light to chemical energy conversion begins. Although LHCs are all highly homologous in their structure and display a variety of common features, each complex finds a specific location and task in the energy transport. One example is CP29, which occupies a pivotal position in Photosystem II, bridging the peripheral antennae to the core. The design principles behind this specificity, however, are still unclear. Here, a synergetic approach combining steady-state and ultrafast spectroscopy, mutational analysis and structure-based exciton modeling allows uncovering the energy landscape of the chlorophylls bound to this complex. We found that, although displaying an overall highly conserved exciton structure very similar to that of other LHCs, CP29 possesses an additional terminal emitter domain. The simultaneous presence of two low energy sites facing the peripheral antennae and the core, allows CP29 to efficiently work as a conduit in the energy flux. Our results show that the LHCs share a common solid architecture but have finely tuned their structure to carry out specific functions.

中文翻译：

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植物日光收集的设计原理：单体天线CP29的功能架构。

在植物和绿藻中，光捕获复合物（LHC）是叶绿素结合蛋白的一个大家族，起着触角的作用，收集太阳光子并将吸收的能量转移到光合作用中心，从那里光到化学能的转化开始。尽管大型强子对撞机在结构上都高度同源并显示出各种共同特征，但每个复合体在能量传输中都找到了特定的位置和任务。一个例子是CP29，它在光电系统II中处于关键位置，将外围天线桥接到核心。然而，这种特殊性背后的设计原理仍不清楚。在这里，一种结合了稳态和超快光谱的协同方法，突变分析和基于结构的激子建模可以揭示与该复合物结合的叶绿素的能量分布。我们发现，尽管显示的总体高度保守的激子结构与其他LHC极为相似，但CP29拥有一个额外的末端发射极域。面对外围天线和核心的两个低能量站点同时存在，使CP29可以有效地充当能量通量中的导管。我们的结果表明，大型强子对撞机共享一个通用的实体架构，但对其结构进行了微调以执行特定功能。面对外围天线和核心的两个低能量站点同时存在，使CP29可以有效地充当能量通量中的导管。我们的结果表明，大型强子对撞机共享一个通用的实体架构，但对其结构进行了微调以执行特定功能。面对外围天线和核心的两个低能量站点同时存在，使CP29可以有效地充当能量通量中的导管。我们的结果表明，大型强子对撞机共享一个通用的实体架构，但对其结构进行了微调以执行特定功能。