植物光系统II反应中心的三维结构,分辨率为8A
K H Rhee1, E P Morris, J Barber
1Max-Planck-Institut für Biophysik, Abteilung Strukturbiologie, Frankfurt am Main, Germany.
Nature
|December 2, 1998
概括
研究人员使用电子晶体学确定了光系统II子综合体的结构. 这揭示了对光驱动反应和与其他光系统的进化联系的洞察力.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 光合作用研究研究 光合作用研究
背景情况:
- 光系统II (PSII) 是植物光合作用中的关键酶复合体,负责利用太阳能分解水.
- 原生PSII是一个大型,复杂的组合,由25多个子单位组成,分子质量超过600K.
- 了解PSII结构是阐明光合作用机制和潜在的生物能源应用的关键.
研究的目的:
- 为了确定一个特定的光系统II子综合体的三维结构.
- 在这个子复合体内研究D1,D2,CP47和细胞染色体b-559蛋白的功能能力和结构组织.
主要方法:
- 电子晶体学被用来解决结构.
- 该研究的重点是含有D1,D2,CP47和细胞染色体b-559蛋白质的子复合体.
主要成果:
- 确定了CP47反应中心子复合体 (160K) 的三维结构.
- 这个子综合体执行光介导的能量和电子转移,但不能氧化水.
- 该结构显示了23个跨膜α螺旋环,其中16个被分配给D1,D2和CP47蛋白.
- 紫色细菌和植物光系统I反应中心的结构相似性表明它们具有共同的进化起源.
- 氧化辅因子的位置与细菌反应中心相似,但"特殊对"的叶绿素之间的距离更大.
结论:
- 确定的结构提供了一个功能性的光系统II子综合体的详细视图.
- 结构上的相似之处凸显了光合作用反应中心的保存进化途径.
- 这些发现提供了关于光合作用过程中光能转化早期阶段的见解.
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