7DGR

Activity optimized supercomplex state2

This is a non-PDB format compatible entry.

Summary for 7DGR

• Entry DOI: 10.2210/pdb7dgr/pdb
• EMDB information: 30674
• Descriptor: NADH dehydrogenase [ubiquinone] flavoprotein 2, mitochondrial, NADH-ubiquinone oxidoreductase 75 kDa subunit, mitochondrial, NADH dehydrogenase [ubiquinone] iron-sulfur protein 2, mitochondrial, ... (81 entities in total)
• Functional Keywords: complex i, respiratory, electron transport, oxidoreductase
• Biological source: Bos taurus (Bovine); More
• Total number of polymer chains: 80
• Total formula weight: 1712399.04

Authors

Jeon, T.J.,Lee, S.G.,Yoo, S.H.,Ryu, J.H.,Kim, D.S.,Hyun, J.K.,Kim, H.M.,Ryu, S.E. (deposition date: 2020-11-12, release date: 2022-05-18)

Primary citation

Jeon, T.J.,Lee, S.G.,Yoo, S.H.,Kim, M.,Song, D.,Ryu, J.,Park, H.,Kim, D.S.,Hyun, J.,Kim, H.M.,Ryu, S.E.
A Dynamic Substrate Pool Revealed by cryo-EM of a Lipid-Preserved Respiratory Supercomplex.
Antioxid.Redox Signal., 2022

PubMed Abstract: Mitochondrial respiratory supercomplexes mediate redox electron transfer, generating a proton gradient for ATP synthesis. To provide structural information on the function of supercomplexes in physiologically relevant conditions, we conducted cryoelectron microscopy studies with supercomplexes in a lipid-preserving state. Here, we present cryoelectron microscopy structures of bovine respiratory supercomplex IIIIIV by using a lipid-preserving sample preparation. The preparation greatly enhances the intercomplex quinone transfer activity. The structures reveal large intercomplex motions that result in different shapes and sizes of the intercomplex space between complexes I and III, forming a dynamic substrate pool. Biochemical and structural analyses indicated that intercomplex phospholipids mediate the intercomplex motions. An analysis of the different classes of focus-refined complex I showed that structural switches due to quinone reduction led to the formation of a novel channel that could transfer reduced quinones to the intercomplex substrate pool. Our results indicate potential mechanism for the facilitated electron transfer involving a dynamic substrate pool and intercomplex movement by which supercomplexes play an active role in the regulation of metabolic flux and reactive oxygen species.

PubMed: 34913730
DOI: 10.1089/ars.2021.0114

Experimental method

ELECTRON MICROSCOPY (4.6 Å)