biostudies-literatureZheng WNIGMS NIH HHSNIH HHS232-239https://www.ebi.ac.uk/biostudies/studies/S-EPMC11222160biostudies-literatureUnknown631(8019)Mitochondria play a pivotal part in ATP energy production through oxidative phosphorylation, which occurs within the inner membrane through a series of respiratory complexes^1-4. Despite extensive in vitro structural studies, determining the atomic details of their molecular mechanisms in physiological states remains a major challenge, primarily because of loss of the native environment during purification. Here we directly image porcine mitochondria using an in situ cryo-electron microscopy approach. This enables us to determine the structures of various high-order assemblies of respiratory supercomplexes in their native states. We identify four main supercomplex organizations: I₁III₂IV₁, I₁III₂IV₂, I₂INatureHigh-resolution in situ structures of mammalian respiratory supercomplexes.PMC11222160S10 OD023603R35 GM142959Zhu JZhang KChai PZheng WfalseHigh-resolution in situ structures of mammalian respiratory supercomplexes.Mitochondria play a pivotal part in ATP energy production through oxidative phosphorylation, which occurs within the inner membrane through a series of respiratory complexes^1-4. Despite extensive in vitro structural studies, determining the atomic details of their molecular mechanisms in physiological states remains a major challenge, primarily because of loss of the native environment during purification. Here we directly image porcine mitochondria using an in situ cryo-electron microscopy approach. This enables us to determine the structures of various high-order assemblies of respiratory supercomplexes in their native states. We identify four main supercomplex organizations: I₁III₂IV₁, I₁III₂IV₂, I₂I2024-01-01T00:00:00Z2024 Jul2026-05-29T11:44:38.4Z2024-11-14T17:01:26.808ZS-EPMC112221603881172210.1038/s41586-024-07488-9