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-Structure paper
タイトル | A Native LH1-RC-HiPIP Supercomplex from an Extremophilic Phototroph. |
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ジャーナル・号・ページ | Commun Biol, Vol. 8, Issue 1, Page 42, Year 2025 |
掲載日 | 2025年1月11日 |
![]() | Kazutoshi Tani / Ryo Kanno / Kenji V P Nagashima / Mai Kawakami / Naho Hiwatashi / Kazuna Nakata / Sakiko Nagashima / Kazuhito Inoue / Shinichi Takaichi / Endang R Purba / Malgorzata Hall / Long-Jiang Yu / Michael T Madigan / Akira Mizoguchi / Bruno M Humbel / Yukihiro Kimura / Zheng-Yu Wang-Otomo / ![]() ![]() ![]() |
PubMed 要旨 | Halorhodospira (Hlr.) halophila strain BN9622 is an extremely halophilic and alkaliphilic purple phototrophic bacterium and has been widely used as a model for exploring the osmoadaptive and ...Halorhodospira (Hlr.) halophila strain BN9622 is an extremely halophilic and alkaliphilic purple phototrophic bacterium and has been widely used as a model for exploring the osmoadaptive and photosynthetic strategies employed by phototrophic extreme halophiles that enable them to thrive in hypersaline environments. Here we present the cryo-EM structures of (1) a unique native Hlr. halophila triple-complex formed from light-harvesting (LH1), the reaction center (RC), and high-potential iron-sulfur protein (HiPIP) at 2.44 Å resolution, and (2) a HiPIP-free LH1-RC complex at 2.64 Å resolution. Differing from the LH1 in the Hlr. halophila LH1-LH2 co-complex where LH1 encircles LH2, the RC-associated LH1 complex consists of 16 (rather than 18) αβ-subunits circularly surrounding the RC. These distinct forms of LH1 indicate that the number of subunits in a Hlr. halophila LH1 complex is flexible and its size is a function of the photocomplex it encircles. Like LH1 in the LH1-LH2 co-complex, the RC-associated LH1 complex also contained two forms of αβ-polypeptides and both dimeric and monomeric molecules of bacteriochlorophyll a. The majority of the isolated Hlr. halophila LH1-RC complexes contained the electron donor HiPIP bound to the surface of the RC cytochrome subunit near the heme-1 group. The bound HiPIP consisted of an N-terminal functional domain and a long C-terminal extension firmly attached to the cytochrome subunit. Despite overall highly negative surface-charge distributions for both the cytochrome subunit and HiPIP, the interface between the two proteins was relatively uncharged and neutral, forming a pathway for electron tunneling. The structure of the Hlr. halophila LH1-RC-HiPIP complex provides insights into the mechanism of light energy acquisition coupled with a long-distance electron donating process toward the charge separation site in a multi-extremophilic phototroph. |
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手法 | EM (単粒子) |
解像度 | 2.4 - 2.6 Å |
構造データ | EMDB-39836, PDB-8z82: EMDB-39837, PDB-8z83: |
化合物 | ![]() ChemComp-HEC: ![]() ChemComp-MG: ![]() ChemComp-Z41: ![]() ChemComp-PLM: ![]() ChemComp-PGV: ![]() ChemComp-LMT: ![]() ChemComp-BCL: ![]() ChemComp-BPH: ![]() ChemComp-UQ8: ![]() ChemComp-CDL: ![]() ChemComp-FE: ![]() ChemComp-MQ8: ![]() ChemComp-CRT: ![]() ChemComp-SF4: ![]() ChemComp-HOH: |
由来 |
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![]() | PHOTOSYNTHESIS / LH1-RC |