6XI0

R. capsulatus cyt bc1 (CIII2) at 3.3A

Summary for 6XI0

• Entry DOI: 10.2210/pdb6xi0/pdb
• EMDB information: 22189
• Descriptor: Ubiquinol-cytochrome c reductase iron-sulfur subunit, Cytochrome b, Cytochrome c1, ... (5 entities in total)
• Functional Keywords: cytochrome bc1 membrane protein complex ubiquinone:cytochrome c oxidoreductase complex iii, oxidoreductase
• Biological source: Rhodobacter capsulatus (strain ATCC BAA-309 / NBRC 16581 / SB1003); More
• Total number of polymer chains: 6
• Total formula weight: 204471.04

Authors

Steimle, S.,Van Eeuwen, T.,Ozturk, Y.,Kim, H.J.,Braitbard, M.,Selamoglu, N.,Garcia, B.A.,Schneidman-Duhovny, D.,Murakami, K.,Daldal, F. (deposition date: 2020-06-19, release date: 2020-12-30, Last modification date: 2024-11-13)

Primary citation

Steimle, S.,van Eeuwen, T.,Ozturk, Y.,Kim, H.J.,Braitbard, M.,Selamoglu, N.,Garcia, B.A.,Schneidman-Duhovny, D.,Murakami, K.,Daldal, F.
Cryo-EM structures of engineered active bc 1 -cbb 3 type CIII 2 CIV super-complexes and electronic communication between the complexes.
Nat Commun, 12:929-929, 2021

PubMed Abstract: Respiratory electron transport complexes are organized as individual entities or combined as large supercomplexes (SC). Gram-negative bacteria deploy a mitochondrial-like cytochrome (cyt) bc (Complex III, CIII), and may have specific cbb-type cyt c oxidases (Complex IV, CIV) instead of the canonical aa-type CIV. Electron transfer between these complexes is mediated by soluble (c) and membrane-anchored (c) cyts. Here, we report the structure of an engineered bc-cbb type SC (CIIICIV, 5.2 Å resolution) and three conformers of native CIII (3.3 Å resolution). The SC is active in vivo and in vitro, contains all catalytic subunits and cofactors, and two extra transmembrane helices attributed to cyt c and the assembly factor CcoH. The cyt c is integral to SC, its cyt domain is mobile and it conveys electrons to CIV differently than cyt c. The successful production of a native-like functional SC and determination of its structure illustrate the characteristics of membrane-confined and membrane-external respiratory electron transport pathways in Gram-negative bacteria.

PubMed: 33568648
DOI: 10.1038/s41467-021-21051-4

Experimental method

ELECTRON MICROSCOPY (3.3 Å)