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Title | An LH1-RC photocomplex from an extremophilic phototroph provides insight into origins of two photosynthesis proteins. |
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Journal, issue, pages | Commun Biol, Vol. 5, Issue 1, Page 1197, Year 2022 |
Publish date | Nov 7, 2022 |
Authors | Kazutoshi Tani / Ryo Kanno / Keigo Kurosawa / Shinichi Takaichi / Kenji V P Nagashima / Malgorzata Hall / Long-Jiang Yu / Yukihiro Kimura / Michael T Madigan / Akira Mizoguchi / Bruno M Humbel / Zheng-Yu Wang-Otomo / |
PubMed Abstract | Rhodopila globiformis is the most acidophilic of anaerobic purple phototrophs, growing optimally in culture at pH 5. Here we present a cryo-EM structure of the light-harvesting 1-reaction center (LH1- ...Rhodopila globiformis is the most acidophilic of anaerobic purple phototrophs, growing optimally in culture at pH 5. Here we present a cryo-EM structure of the light-harvesting 1-reaction center (LH1-RC) complex from Rhodopila globiformis at 2.24 Å resolution. All purple bacterial cytochrome (Cyt, encoded by the gene pufC) subunit-associated RCs with known structures have their N-termini truncated. By contrast, the Rhodopila globiformis RC contains a full-length tetra-heme Cyt with its N-terminus embedded in the membrane forming an α-helix as the membrane anchor. Comparison of the N-terminal regions of the Cyt with PufX polypeptides widely distributed in Rhodobacter species reveals significant structural similarities, supporting a longstanding hypothesis that PufX is phylogenetically related to the N-terminus of the RC-bound Cyt subunit and that a common ancestor of phototrophic Proteobacteria contained a full-length tetra-heme Cyt subunit that evolved independently through partial deletions of its pufC gene. Eleven copies of a novel γ-like polypeptide were also identified in the bacteriochlorophyll a-containing Rhodopila globiformis LH1 complex; γ-polypeptides have previously been found only in the LH1 of bacteriochlorophyll b-containing species. These features are discussed in relation to their predicted functions of stabilizing the LH1 structure and regulating quinone transport under the warm acidic conditions. |
External links | Commun Biol / PubMed:36344631 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.24 Å |
Structure data | EMDB-33501, PDB-7xxf: |
Chemicals | ChemComp-HEC: ChemComp-PGV: ChemComp-BCL: ChemComp-BPH: ChemComp-U10: ChemComp-LMT: ChemComp-FE: ChemComp-MQ9: ChemComp-I7D: ChemComp-CDL: ChemComp-PEE: ChemComp-HOH: |
Source |
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Keywords | PHOTOSYNTHESIS / LH1-RC COMPLEX / PURPLE BACTERIA |