Structural basis for the assembly and quinone transport mechanisms of the dimeric photosynthetic RC-LH1 supercomplex.
Structural basis for the assembly and quinone transport mechanisms of the dimeric photosynthetic RC-LH1 supercomplex.
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DOI：
10.1038/s41467-022-29563-3
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发表时间：
2022-04-13
影响因子：
16.6
通讯作者：
中科院分区：
文献类型：
--
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反应中心（RC）和捕光复合物1（LH 1）形成一个RC-LH 1核心超复合物，该超复合物对紫色光养细菌光合作用的初级反应至关重要。一些物种具有与跨膜多肽PufX的二聚体RC-LH 1复合物，其代表在不产氧光养生物中最大的光合复合物。然而，RC-LH 1二聚体的结构和组装机制的细节尚不清楚。在这里，我们报告七个冷冻电子显微镜（cryo-EM）结构的RC-LH 1超复合物从Rhodobacter sphaeroides。我们的结构揭示了两个PufX多肽位于S形RC-LH 1二聚体的中心，在组分之间互锁缔合并介导RC-LH 1二聚化。此外，我们确定了另一个跨膜肽，命名为PufY，这是位于RC和LH 1亚基附近的LH 1开放。PufY结合醌分子并阻止LH 1亚基完全包围RC，从而为醌/醌醇交换创造通道。遗传诱变，cryo-EM结构，和计算机模拟提供了一个机械的理解的组装和电子传递途径的RC-LH 1二聚体和阐明的作用，确保光合超复合物的结构和功能的完整性的各个组件。细菌光合作用反映了光合作用进化的早期阶段。在这里，作者提出了一个系统的研究cryo-EM结构的二聚体光收获反应中心复合物和装配变体从Rhodobacter sphaeroides，它描绘了一个层次的装配途径和醌运输路线的二聚体光合RC-LH 1核心复合物。
The reaction center (RC) and light-harvesting complex 1 (LH1) form a RC–LH1 core supercomplex that is vital for the primary reactions of photosynthesis in purple phototrophic bacteria. Some species possess the dimeric RC–LH1 complex with a transmembrane polypeptide PufX, representing the largest photosynthetic complex in anoxygenic phototrophs. However, the details of the architecture and assembly mechanism of the RC–LH1 dimer are unclear. Here we report seven cryo-electron microscopy (cryo-EM) structures of RC–LH1 supercomplexes from Rhodobacter sphaeroides. Our structures reveal that two PufX polypeptides are positioned in the center of the S-shaped RC–LH1 dimer, interlocking association between the components and mediating RC–LH1 dimerization. Moreover, we identify another transmembrane peptide, designated PufY, which is located between the RC and LH1 subunits near the LH1 opening. PufY binds a quinone molecule and prevents LH1 subunits from completely encircling the RC, creating a channel for quinone/quinol exchange. Genetic mutagenesis, cryo-EM structures, and computational simulations provide a mechanistic understanding of the assembly and electron transport pathways of the RC–LH1 dimer and elucidate the roles of individual components in ensuring the structural and functional integrity of the photosynthetic supercomplex. Bacterial photosynthesis reflects the early stages of the evolution of photosynthesis. Here, the authors present a systematic study of the cryo-EM structures of the dimeric light harvesting–reaction center complexes and assembly variants from Rhodobacter sphaeroides, which delineated a hierarchical assembly pathway and quinone transport routes of the dimeric photosynthetic RC–LH1 core complex.
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影响因子：
13.6
作者：
Bracun L;Yamagata A;Christianson BM;Terada T;Canniffe DP;Shirouzu M;Liu LN
通讯作者：
Liu LN
影响因子：
3.3
作者：
de Jong, Djurre H.;Liguori, Nicoletta;Marrink, Siewert J.
通讯作者：
Marrink, Siewert J.
影响因子：
5.5
作者：
Best, Robert B.;Zhu, Xiao;Shim, Jihyun;Lopes, Pedro E. M.;Mittal, Jeetain;Feig, Michael;MacKerell, Alexander D., Jr.
通讯作者：
MacKerell, Alexander D., Jr.
影响因子：
4.3
作者：
Adams, Peter G.;Mothersole, David J.;Hunter, C. Neil
通讯作者：
Hunter, C. Neil
影响因子：
4.4
作者：
Bussi, Giovanni;Donadio, Davide;Parrinello, Michele
通讯作者：
Parrinello, Michele