Distinct structural modulation of photosystem I and lipid environment stabilizes its tetrameric assembly
Distinct structural modulation of photosystem I and lipid environment stabilizes its tetrameric assembly
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DOI：
10.1038/s41477-020-0610-x
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发表时间：
2020-03-01
期刊：
影响因子：
18
通讯作者：
Amunts, Alexey
中科院分区：
文献类型：
--
作者：
Chen, Ming;Perez-Boerema, Annemarie;Amunts, Alexey
光系统I（PSI）能够在不同物种中形成不同的寡聚体状态。为了揭示PSI二聚化和四聚化的结构基础，我们从结构上研究了来自鱼腥藻的PSI。这揭示了由于在管腔中缺乏PsaL的末端残基而破坏的三聚化结构域，这导致PSI二聚体在单体之间具有松散的连接，并且比三聚体中的能量耦合叶绿素更弱。在二聚体表面，特定的磷脂、辅因子和相互作用的组合促进了另一个二聚体的募集以形成四聚体。两者合计，松弛的管腔连接和脂质特异性在二聚体界面占膜曲率。PSI四聚体组装似乎增加了类囊体膜的表面积，这将有助于PSI crowding.Photosystem I从蓝藻鱼腥藻有一个中断的三聚结构域，导致单体之间的松散连接的二聚体。二聚体表面的磷脂和辅因子促进进一步二聚化以形成四聚体。
Photosystem I (PSI) is able to form different oligomeric states across various species. To reveal the structural basis for PSI dimerization and tetramerization, we structurally investigated PSI from the cyanobacterium Anabaena. This revealed a disrupted trimerization domain due to lack of the terminal residues of PsaL in the lumen, which resulted in PSI dimers with loose connections between monomers and weaker energy-coupled chlorophylls than in the trimer. At the dimer surface, specific phospholipids, cofactors and interactions in combination facilitated recruitment of another dimer to form a tetramer. Taken together, the relaxed luminal connections and lipid specificity at the dimer interface account for membrane curvature. PSI tetramer assembly appears to increase the surface area of the thylakoid membrane, which would contribute to PSI crowding.Photosystem I from the cyanobacterium Anabaena has a disrupted trimerization domain resulting in dimers with loose connections between monomers. Phospholipids and cofactors at the dimer surface facilitate further dimerization to form a tetramer.