在Arabidopsis中,细胞染色体c(6) 和塑素的功能关系
Rajeev Gupta1, Zengyong He, Sheng Luan
1Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA.
Nature
|May 31, 2002
概括
在Arabidopsis thaliana中发现的一种新发现的类似细胞染色体c6的蛋白质 (Atc6) 可以在光合作用电子传输中功能性取代塑素. 虽然这两种蛋白质都不是单独必需的,但两者都是植物生存所必需的.
科学领域:
- 植物生理学 植物生理学
- 分子生物学分子生物学
- 光合作用研究研究 光合作用研究
背景情况:
- 光合作用电子载体对于植物将光能转化为化学能量至关重要.
- 虽然电子运输链蛋白质被保存,但甲状腺光中的可溶性蛋白质在高等植物和其他光合作用生物之间有所不同.
- 在蓝藻和藻类中,塑素和细胞染色体c(6) 都调解电子转移; 较高的植物被认为只具有塑素.
研究的目的:
- 为了描述Arabidopsis thaliana中一种类似细胞染色体c(6) 的蛋白质,命名为Atc6.6.
- 研究Atc6在光合作用电子传输中的功能作用.
- 为了确定Atc6和塑素对于植物生存的必要性.
主要方法:
- 来自Arabidopsis的细胞染色体c(6) 样蛋白 (Atc6) 的表征.
- 定位研究证实Atc6在甲状腺膜中.
- 电子运输重建试验评估Atc6在替换塑素中的功能.
- 对缺乏塑素和/或Atc6.6的阿拉比多普西斯突变物进行遗传分析.
主要成果:
- 鉴定出Atc6是一种功能性细胞染色体c,定位在甲状腺光层中.
- 电子运输试验表明,Atc6可以替代光合作用电子运输链中的塑素.
- 基因分析显示,塑素和Atc6都不是单独对Arabidopsis生长和发育至关重要的.
- 缺乏塑素和Atc6的植物是不可行的,这表明它们发挥了关键的冗余作用.
结论:
- 与以前的理解相反,更高的植物在甲状腺膜中具有功能性细胞染色体c6类蛋白质 (Atc6).
- 亚特克6和塑素代表了一种冗余的电子转移系统,用于Arabidopsis中的光系统I.
- 塑素和Atc6的联合缺失是致命的,突出了它们在光合作用中的重要,尽管是多余的作用.
相关概念视频
Photosystem II
60.0K
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...
60.0K
Photosystem I
52.9K
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...
52.9K
C4 Pathway and CAM
38.2K
Most plants use the C3 pathway for carbon fixation. However, some plants, such as sugar cane, corn, and cacti that grow in hot conditions, use alternative pathways to fix carbon and conserve energy loss due to photorespiration. Photorespiration is the process that occurs when the oxygen concentration is high. Under such conditions, the rubisco enzyme in the Calvin cycle binds O2 instead of CO2, which halts photosynthesis and consumes energy.
C4 Pathway
The C4 pathway is used by plants such as...
C4 Pathway
The C4 pathway is used by plants such as...
38.2K
The Anatomy of Chloroplasts
7.0K
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...
7.0K
Photosystems
7.1K
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...
7.1K
Protein Transport to the Inner Chloroplast Membrane
1.7K
Proteins targeted to the inner chloroplast membrane, or plastid proteins, are transported by two general pathways: the stop-transfer and the re-insertion or post-import pathways. Most plastid proteins carry N-terminal transit sequences and internal import sequences targeting it to the specific chloroplast subcompartment. Proteins targeted by the stop-transfer pathway have internal hydrophobic sequences that inhibit their translocation into the stroma. As a result, these precursors are arrested...
1.7K


