Structure and assembly mechanism of plant C2S2M2-type PSII-LHCII supercomplex
Structure and assembly mechanism of plant C2S2M2-type PSII-LHCII supercomplex
复制标题
植物C2S2M2型PSII-LHCII超复合物的结构和组装机制。
DOI：
10.1126/science.aan0327
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发表时间：
2017-08-25
期刊：
影响因子：
56.9
通讯作者：
Li, Mei
中科院分区：
文献类型：
--
作者：
Su, Xiaodong;Ma, Jun;Li, Mei
在植物中，光合机械光系统II（PSII）由与可变数量的捕光复合物II（LHCIIs）相关的核心复合物组成。超复合物，包括一个二聚体的核心和两个强结合和两个中度结合的LHCII（C2 S2 M2），是在适应有限的光植物的主导形式。在这里，我们报告冷冻电子显微镜结构的两种形式的C2 S2 M2（称为堆叠和未堆叠）从豌豆在2.7和3.2埃的分辨率，分别。在每个C2 S2 M2中，适度结合的LHCII与外周天线复合物CP 24-CP 29异二聚体和强结合的LHCII特异性组装，以建立色素网络，促进外周的光捕获和能量转移到核心。外周触角的高移动性，包括适度结合的LHCII和CP 24，为植物PSII的功能调节提供了见解。
In plants, the photosynthetic machinery photosystem II (PSII) consists of a core complex associated with variable numbers of light-harvesting complexes II (LHCIIs). The supercomplex, comprising a dimeric core and two strongly bound and two moderately bound LHCIIs (C2S2M2), is the dominant form in plants acclimated to limited light. Here we report cryo-electron microscopy structures of two forms of C2S2M2 (termed stacked and unstacked) from Pisum sativum at 2.7- and 3.2-angstrom resolution, respectively. In each C2S2M2, the moderately bound LHCII assembles specifically with a peripheral antenna complex CP24-CP29 heterodimer and the strongly bound LHCII, to establish a pigment network that facilitates light harvesting at the periphery and energy transfer into the core. The high mobility of peripheral antennae, including the moderately bound LHCII and CP24, provides insights into functional regulation of plant PSII.