9W2U

Cryo-EM structure of complex I on the bovine heart submitochondrial particles, open

Summary for 9W2U

• Entry DOI: 10.2210/pdb9w2u/pdb
• EMDB information: 65580
• Descriptor: NADH-ubiquinone oxidoreductase chain 6, NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, mitochondrial, NADH-ubiquinone oxidoreductase chain 4L, ... (59 entities in total)
• Functional Keywords: respiratory chain complex, supercomplex, submitochondrial particles, motor protein, oxidoreductase
• Biological source: Bos taurus (domestic cattle); More
• Total number of polymer chains: 45
• Total formula weight: 985917.38

Authors

Nakano, A.,Masuya, T.,Akisada, S.,Ishikawa-Fukuda, M.,Mitsuoka, K.,Miyoshi, H.,Murai, M.,Yokoyama, K. (deposition date: 2025-07-28, release date: 2026-04-01)

Primary citation

Nakano, A.,Masuya, T.,Akisada, S.,Ishikawa-Fukuda, M.,Mitsuoka, K.,Miyoshi, H.,Murai, M.,Yokoyama, K.
Structures of respiratory supercomplexes and ATP synthase oligomers in mammalian mitochondrial inner membrane.
Nat Commun, 2026

PubMed Abstract: Understanding the functional mechanisms of membrane protein complexes requires structural analysis within their native membrane environment. Here, we applied cryo-electron microscopy to determine the structures of FF ATP synthase and respiratory supercomplexes (SCs) on sub-mitochondrial particles (SMPs) isolated from bovine heart mitochondria. Most FF complexes were observed as dimers stabilized by the regulatory factor IF₁, and a tetrameric assembly comprising two FF-IF₁ dimers arranged linearly was also identified. This finding indicates that the tetrameric units of FF are present in the mitochondrial inner membrane and contribute to shaping cristae tips in mammalian mitochondria. F domain maps resolve the e-subunit- c₈-ring interface and show no discrete density for a tightly bound lipid within the c₈-ring. In addition to the previously reported SCs compositions CI₁CIII₂CIV₁ and CI₁CIII₂CIV₂, our analysis identified an additional assembly with the composition CI₁CIII₂CIV₃, as well as a CI₂CIII₂CIV₆ mega-complex. This approach enables rapid structural determination of FF ATP synthase and SCs from minimal membrane fractions, providing a foundation for elucidating the molecular basis of metabolic disorders and mitochondrial diseases at the level of higher-order architecture.

PubMed: 41844608
DOI: 10.1038/s41467-026-70578-x

Experimental method

ELECTRON MICROSCOPY (2.6 Å)