Lipidic Sponge Phase Crystal Structure of a Photosynthetic Reaction Center Reveals Lipids on the Protein Surface
Lipidic Sponge Phase Crystal Structure of a Photosynthetic Reaction Center Reveals Lipids on the Protein Surface
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DOI：
10.1021/bi900545e
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发表时间：
2009-10-20
期刊：
影响因子：
2.9
通讯作者：
Katona, Gergely
中科院分区：
文献类型：
--
作者：
Wohri, Annemarie B.;Wahlgren, Weixiao Y.;Katona, Gergely
膜蛋白嵌入脂质双层中，并与脂质分子保持强烈的相互作用。紧密结合的脂质负责膜中蛋白质的垂直定位和整合以及多亚基复合物的组装，有时充当底物。在这项工作中，Ye 展示了反应中心从 Blastoloris viridis 到 1.86 埃的脂质海绵相晶体结构，揭示了脂质分子与蛋白质表面的相互作用。二酰基甘油分子通过硫醚键结合至四血红素细胞色素 c 亚基的 N 末端。从 Q(B) 位点恢复的电子密度和脂质海绵相生长晶体中观察到的重组动力学变化来看，移动的泛醌似乎被单油酸甘油酯分子取代。在属于 H 和 M 亚基的跨膜螺旋的界面处观察到 36 埃长的电子密度特征，可能来自一种未鉴定的脂质。
Membrane proteins are embedded in a lipid bilayer and maintain strong interactions with lipid molecules, Tightly bound lipids are responsible for vertical positioning and integration of proteins in the membrane and for assembly of multisubunit complexes and occasionally act as substrates. In this work Ye present the lipidic sponge phase crystal structure of the reaction center from Blastochloris viridis to 1.86 angstrom, which reveals lipid molecules interacting with the protein surface. A diacylglycerol molecule is bound, through a thioether bond, to the N-terminus of the tetraheme cytochrome c subunit. From the electron density recovered at the Q(B) site and the observed change in recombination kinetics in lipidic sponge phase-grown crystals, the mobile ubiquinone appears to be displaced by a monoolein molecule. A 36 angstrom long electron density feature is observed at the interface of transmembrane helices belonging to the H- and M-subunits, probably arising from an unidentified lipid.