密码植物光系统II的结构 - 光采集天线超复杂
Yu-Zhong Zhang1,2,3, Kang Li4,5, Bing-Yue Qin6
1Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China. zhangyz@sdu.edu.cn.
Nature communications
|June 12, 2024
概括
密码植物利用独特的采光复合体 (ACP) 进行高效的光合作用. 这项研究揭示了它们的光系统II-ACPII超级复合体的结构,提供了对能量转移和与红藻的进化联系的见解.
科学领域:
- 光合作用研究研究光合作用.
- 结构生物学是结构生物学.
- 藻类的进化过程
背景情况:
- 加密植物是古代的光合作用生物体,起源于红藻,通过二次内生共生.
- 它们具有作为光收获复合体 (LHC) 起作用的阿洛丁-甲/c2结合蛋白 (ACP).
- 这些特征对于高效的氧光合作用和理解红血统塑进化是至关重要的.
研究的目的:
- 确定来自Croomonas placoidea的光系统II (PSII) -ACPII超复合物的冷电子显微镜结构.
- 阐明加密植物光采集复合体的结构组织和进化关系.
- 了解加密植物光合作用过程中光能捕获和转移的机制.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于高分辨率的结构确定.
- 生物化学分析以确定关键蛋白质子单元.
- 计算建模用于激发能量传输路径分析.
主要成果:
- 该结构显示了一个与十二个ACPII单体相关的PSII二元体,组织成四个线性三元体.
- 这些trimers与红藻LHC和与光系统I (PSI) 相互作用的加密植物ACPItrimers具有结构上的相似之处.
- 一个新的Chl-a结合子单元,Psb-γ,被确定为PSII-ACPII复合体稳定性的关键.
结论:
- 该研究为加密植物PSII-ACPII超级复合体中光能捕获和转移提供了详细的结构基础.
- 它强调了密码植物和红藻光采集系统之间的进化联系.
- 这些发现有助于了解PSII-LHCII复合物的多样性和红血统LHCIIs的演变.
相关概念视频
The Antenna Complex
6.0K
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency...
6.0K
Photosystem II
70.1K
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
70.1K
Photosystems
4.8K
Photosystems are multiprotein complexes that form the functional units of photosynthesis in plants, algae, and cyanobacteria. They are found embedded in the membrane of tiny sac-like structures called thylakoids placed inside the chloroplast.
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment...
Functioning of Photosystems
Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment...
4.8K
Photosystem I
62.0K
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
62.0K
The Photochemical Reaction Center
4.1K
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
4.1K
The Supercomplexes in the Crista Membrane
2.5K
The mitochondrial cristae membrane is the primary site for the oxidative phosphorylation (OXPHOS) process of energy conversion mediated through respiratory complexes I to V. These complexes have been widely studied for decades, and it has been proven that they form supramolecular structures called respiratory supercomplexes (SC). These higher-order complexes may be crucial in maintaining the biochemical structure and improving the physiological activity of the individual complexes while...
2.5K


