Crystal structure of spinach major light-harvesting complex at 2.72 Å resolution
Crystal structure of spinach major light-harvesting complex at 2.72 Å resolution
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DOI：
10.1038/nature02373
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发表时间：
2004-03-18
期刊：
影响因子：
64.8
通讯作者：
Chang, WR
中科院分区：
文献类型：
--
作者：
Liu, ZF;Yan, HC;Chang, WR
光系统II的主要光收集复合物（LHC-II）是绿色植物光合作用的主要太阳能收集器，可能也具有强光条件下的光保护作用。在这里，我们报道了二十面体蛋白脂质体组装中LHC-II的第一个x射线结构的原子细节。一个大型R32单体胞的不对称单元包含十个LHC-II单体。每个单体中的14个叶绿素（Chl）可以明确地区分为8个Chla分子和6个Chlb分子。每个叶绿素的过渡偶极矩的取向分配已经实现。所有Chlb都位于相邻单体之间的界面周围，它们与Chla一起是高效光收集的基础。每个单体已经观察到四个类胡萝卜素结合位点。叶黄素循环类胡萝卜素在单体-单体界面可能参与过量能量的非辐射耗散，这是植物进化出的光保护策略之一。
The major light-harvesting complex of photosystem II (LHC-II) serves as the principal solar energy collector in the photosynthesis of green plants and presumably also functions in photoprotection under high-light conditions. Here we report the first X-ray structure of LHC-II in icosahedral proteoliposome assembly at atomic detail. One asymmetric unit of a large R32 unit cell contains ten LHC-II monomers. The 14 chlorophylls (Chl) in each monomer can be unambiguously distinguished as eight Chla and six Chlb molecules. Assignment of the orientation of the transition dipole moment of each chlorophyll has been achieved. All Chlb are located around the interface between adjacent monomers, and together with Chla they are the basis for efficient light harvesting. Four carotenoid-binding sites per monomer have been observed. The xanthophyll-cycle carotenoid at the monomer - monomer interface may be involved in the non-radiative dissipation of excessive energy, one of the photoprotective strategies that have evolved in plants.