7C9R

STRUCTURE OF PHOTOSYNTHETIC LH1-RC SUPER-COMPLEX OF THIORHODOVIBRIO STRAIN 970

Summary for 7C9R

• Entry DOI: 10.2210/pdb7c9r/pdb
• EMDB information: 30314
• Descriptor: Photosynthetic reaction center cytochrome c subunit, Alpha subunit 2 of light-harvesting 1 complex, PROTOPORPHYRIN IX CONTAINING FE, ... (24 entities in total)
• Functional Keywords: lh1-rc, photosynthesis, purple bacteria
• Biological source: Thiorhodovibrio sp. 970; More
• Total number of polymer chains: 36
• Total formula weight: 442274.37

Authors

Tani, K.,Kanno, R.,Makino, Y.,Hall, M.,Takenouchi, M.,Imanishi, M.,Yu, L.-J.,Overmann, J.,Madigan, M.T.,Kimura, Y.,Mizoguchi, A.,Humbel, B.M.,Wang-Otomo, Z.-Y. (deposition date: 2020-06-07, release date: 2020-10-07, Last modification date: 2020-10-14)

Primary citation

Tani, K.,Kanno, R.,Makino, Y.,Hall, M.,Takenouchi, M.,Imanishi, M.,Yu, L.J.,Overmann, J.,Madigan, M.T.,Kimura, Y.,Mizoguchi, A.,Humbel, B.M.,Wang-Otomo, Z.Y.
Cryo-EM structure of a Ca 2+ -bound photosynthetic LH1-RC complex containing multiple alpha beta-polypeptides.
Nat Commun, 11:4955-4955, 2020

PubMed Abstract: The light-harvesting-reaction center complex (LH1-RC) from the purple phototrophic bacterium Thiorhodovibrio strain 970 exhibits an LH1 absorption maximum at 960 nm, the most red-shifted absorption for any bacteriochlorophyll (BChl) a-containing species. Here we present a cryo-EM structure of the strain 970 LH1-RC complex at 2.82 Å resolution. The LH1 forms a closed ring structure composed of sixteen pairs of the αβ-polypeptides. Sixteen Ca ions are present in the LH1 C-terminal domain and are coordinated by residues from the αβ-polypeptides that are hydrogen-bonded to BChl a. The Ca-facilitated hydrogen-bonding network forms the structural basis of the unusual LH1 redshift. The structure also revealed the arrangement of multiple forms of α- and β-polypeptides in an individual LH1 ring. Such organization indicates a mechanism of interplay between the expression and assembly of the LH1 complex that is regulated through interactions with the RC subunits inside.

PubMed: 33009385
DOI: 10.1038/s41467-020-18748-3

Experimental method

ELECTRON MICROSCOPY (2.82 Å)