8BEL

Cryo-EM structure of the Arabidopsis thaliana I+III2 supercomplex (CIII membrane domain)

Summary for 8BEL

• Entry DOI: 10.2210/pdb8bel/pdb
• EMDB information: 16007
• Descriptor: Cytochrome b, 1,2-DIACYL-GLYCEROL-3-SN-PHOSPHATE, (1S)-2-{[{[(2R)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PALMITOYLOXY)METHYL]ETHYL STEARATE, ... (18 entities in total)
• Functional Keywords: plant, mitochondria, complex, membrane protein
• Biological source: Arabidopsis thaliana (thale cress); More
• Total number of polymer chains: 14
• Total formula weight: 309393.06

Authors

Klusch, N.,Kuehlbrandt, W. (deposition date: 2022-10-21, release date: 2023-01-11, Last modification date: 2024-11-13)

Primary citation

Klusch, N.,Dreimann, M.,Senkler, J.,Rugen, N.,Kuhlbrandt, W.,Braun, H.P.
Cryo-EM structure of the respiratory I + III 2 supercomplex from Arabidopsis thaliana at 2 angstrom resolution.
Nat.Plants, 9:142-156, 2023

PubMed Abstract: Protein complexes of the mitochondrial respiratory chain assemble into respiratory supercomplexes. Here we present the high-resolution electron cryo-microscopy structure of the Arabidopsis respiratory supercomplex consisting of complex I and a complex III dimer, with a total of 68 protein subunits and numerous bound cofactors. A complex I-ferredoxin, subunit B14.7 and P9, a newly defined subunit of plant complex I, mediate supercomplex formation. The component complexes stabilize one another, enabling new detailed insights into their structure. We describe (1) an interrupted aqueous passage for proton translocation in the membrane arm of complex I; (2) a new coenzyme A within the carbonic anhydrase module of plant complex I defining a second catalytic centre; and (3) the water structure at the proton exit pathway of complex III with a co-purified ubiquinone in the Q site. We propose that the main role of the plant supercomplex is to stabilize its components in the membrane.

PubMed: 36585502
DOI: 10.1038/s41477-022-01308-6

Experimental method

ELECTRON MICROSCOPY (2.25 Å)