Structure of a thermophilic cyanobacterial b6f-type Rieske protein
Structure of a thermophilic cyanobacterial b6f-type Rieske protein
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DOI：
10.1107/s0907444912034129
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发表时间：
2012-10-01
影响因子：
2.2
通讯作者：
Miki, Kunio
中科院分区：
文献类型：
--
作者：
Veit, Sebastian;Takeda, Kazuki;Miki, Kunio
“Rieske 蛋白”PetC 是细胞色素 b6f 复合物的关键亚基之一。其Rieske型[2Fe2S]簇参与光合电子传输链。对来自嗜热蓝细菌Thermosynechocaccus elongatus BP-1的PetC外在可溶结构域进行2.0埃分辨率的过表达和仔细结构分析，实现了深入的光谱和结构表征，并提出了新的结构特征。特别是，与其他原核PetCs相比，蛋白质结构和内部水分子的位置出乎意料地显示出与真核PetCs更高的相似性。该结构还揭示了 PetC 表面上的一个深袋，该袋朝向整个复合物的膜表面。其表面特性表明存在疏水性化合物的结合位点，并且所有已知 PetC 序列中口袋形成残基的完全保守表明该口袋在细胞色素 b6f 复合物中的功能重要性。
The `Rieske protein' PetC is one of the key subunits of the cytochrome b6f complex. Its Rieske-type [2Fe2S] cluster participates in the photosynthetic electron-transport chain. Overexpression and careful structure analysis at 2.0 angstrom resolution of the extrinsic soluble domain of PetC from the thermophilic cyanobacterium Thermosynechococcus elongatus BP-1 enabled in-depth spectroscopic and structural characterization and suggested novel structural features. In particular, both the protein structure and the positions of the internal water molecules unexpectedly showed a higher similarity to eukaryotic PetCs than to other prokaryotic PetCs. The structure also revealed a deep pocket on the PetC surface which is oriented towards the membrane surface in the whole complex. Its surface properties suggest a binding site for a hydrophobic compound and the complete conservation of the pocket-forming residues in all known PetC sequences indicates the functional importance of this pocket in the cytochrome b6f complex.