密码植物光系统II的独特核心天线组件的结构基础
Long Si1,2, Shumeng Zhang1, Xiaodong Su1,2
1Key Laboratory of Biomacromolecules (CAS), National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Nature communications
|August 9, 2024
概括
这项研究揭示了加密植物光系统II的结构,其中含有叶绿素a/c结合蛋白 (CACs). CACs的独特排列和一种新的蛋白质 (CAL-II) 可能会在压力下稳定该复合体.
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.
- 植物科学 植物科学
背景情况:
- 光系统II (PSII) 对于光合作用至关重要,驱动光捕获和水氧化.
- 外围天线增强PSII的吸光能力,但它们的成分在物种之间有所不同.
- 加密植物利用叶绿素a/c结合蛋白 (CACs) 作为天线,其组装机制尚不清楚.
研究的目的:
- 确定CAC组装的结构基础与密码体中的PSII核心.
- 阐明新型蛋白质在PSII-CAC复合体结构和功能中的作用.
主要方法:
- 净化加密植物的PSII-CAC复合体.
- 高分辨率 (2.57 Å) 低温电子显微镜结构的确定.
主要成果:
- 解决了二维PSII-CAC复合物的结构.
- 每个单体包括核心复合物,六个CAC和一种新的叶绿素结合蛋白 (CAL-II).
- CACs形成一个双层弧形,CAL-II桥梁核心子单元和CACs.
结论:
- CAC和CAL-II的独特组织可能会稳定二维PSII-CAC复合体.
- 这个结构为PSII-CAC组装和加密植物适应环境压力提供了洞察力.
- 这些发现推动了我们对光采集复杂进化和功能的理解.
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
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
Photosystem II
70.0K
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...
70.0K
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 Anatomy of Chloroplasts
5.1K
Green algae and plants, including green stems and unripe fruit, harbor specialized organelles called chloroplasts to carry out photosynthesis. They coordinate both stages of photosynthesis — the light-dependent reactions and the light-independent reactions. The light-dependent reactions use sunlight to release oxygen and produce chemical energy in the form of ATP and NADPH, and the light-independent reactions capture CO2 and use ATP and NADPH to produce sugar.
Structure of...
Structure of...
5.1K


