Fromme Petra, Kern Jan, Loll Bernhard, Biesiadka Jaceck, Saenger Wolfram, Witt Horst T, Krauss Norbert, Zouni Athina
Max-Volmer-Laboratorium für Biophysikalische Chemie und Biochemie, Technische Universität Berlin, Strasse den 17 Juni 135, 10623 Berlin, Germany.
Philos Trans R Soc Lond B Biol Sci. 2002 Oct 29;357(1426):1337-44; discussion 1344-5, 1367. doi: 10.1098/rstb.2002.1143.
The structure of photosystem I at 3.8 A resolution illustrated the main structural elements of the water-oxidizing photosystem II complex, including the constituents of the electron transport chain. The location of the Mn cluster within the complex has been identified for the first time to our knowledge. At this resolution, no individual atoms are visible, however, the electron density of the Mn cluster can be used to discuss both the present models of the Mn cluster as revealed from various spectroscopic methods and the implications for the mechanisms of water oxidation. Twenty-six chlorophylls from the antenna system of photosystem II have been identified. They are arranged in two layers, one close to the stromal side and one close to the lumenal side. Comparing the structure of the antenna system of photosystem II with the chlorophyll arrangement in photosystem I, which was recently determined at 2.5 A resolution shows that photosystem II lacks the central domain of the photosystem I antenna, which is discussed in respect of the repair cycle of photosystem II due to photoinhibition.
分辨率为3.8埃的光系统I结构阐明了水氧化光系统II复合物的主要结构元件，包括电子传递链的组成部分。据我们所知，首次确定了复合物中锰簇的位置。在此分辨率下，看不到单个原子，然而，锰簇的电子密度可用于讨论从各种光谱方法揭示的锰簇当前模型以及对水氧化机制的影响。已鉴定出光系统II天线系统中的26个叶绿素。它们排列成两层，一层靠近基质侧，一层靠近腔侧。将光系统II天线系统的结构与最近以2.5埃分辨率确定的光系统I中的叶绿素排列进行比较，结果表明光系统II缺乏光系统I天线的中心结构域，这在光抑制导致的光系统II修复循环方面进行了讨论。
