7XXF

Structure of photosynthetic LH1-RC super-complex of Rhodopila globiformis

Summary for 7XXF

• Entry DOI: 10.2210/pdb7xxf/pdb
• EMDB information: 33501
• Descriptor: Photosynthetic reaction center cytochrome c subunit, BACTERIOCHLOROPHYLL A, BACTERIOPHEOPHYTIN A, ... (19 entities in total)
• Functional Keywords: lh1-rc complex, photosynthesis, purple bacteria
• Biological source: Rhodopila globiformis; More
• Total number of polymer chains: 47
• Total formula weight: 481881.76

Authors

Tani, K.,Kanno, R.,Kurosawa, K.,Takaichi, S.,Nagashima, K.V.P.,Hall, M.,Yu, L.-J.,Kimura, Y.,Madigan, M.T.,Mizoguchi, A.,Humbel, B.M.,Wang-Otomo, Z.-Y. (deposition date: 2022-05-30, release date: 2022-11-16, Last modification date: 2022-11-23)

Primary citation

Tani, K.,Kanno, R.,Kurosawa, K.,Takaichi, S.,Nagashima, K.V.P.,Hall, M.,Yu, L.J.,Kimura, Y.,Madigan, M.T.,Mizoguchi, A.,Humbel, B.M.,Wang-Otomo, Z.Y.
An LH1-RC photocomplex from an extremophilic phototroph provides insight into origins of two photosynthesis proteins.
Commun Biol, 5:1197-1197, 2022

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-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.

PubMed: 36344631
DOI: 10.1038/s42003-022-04174-2

Experimental method

ELECTRON MICROSCOPY (2.24 Å)