biostudies-literatureUnknown15(1)Zhang YThe 2-oxoglutarate dehydrogenase complex (OGDHc) orchestrates a critical reaction regulating the TCA cycle. Although the structure of each OGDHc subunit has been solved, the architecture of the intact complex and inter-subunit interactions still remain unknown. Here we report the assembly of native, intact OGDHc from Sus scrofa heart tissue using cryo-electron microscopy (cryo-EM), cryo-electron tomography (cryo-ET), and subtomogram averaging (STA) to discern native structures of the whole complex and each subunit. Our cryo-EM analyses revealed the E2o cubic core structure comprising eight homotrimers at 3.3-Å resolution. More importantly, the numbers, positions and orientations of each OGDHc subunit were determined by cryo-ET and the STA structures of the core were resolved at 7.9-Å with Nature communications8407https://www.ebi.ac.uk/biostudies/studies/S-EPMC11436768biostudies-literatureMolecular architecture of the mammalian 2-oxoglutarate dehydrogenase complex.PMC11436768Yang ZZhang YChen MYang MZhang MChen XGao XZhang SYin JfalseMolecular architecture of the mammalian 2-oxoglutarate dehydrogenase complex.The 2-oxoglutarate dehydrogenase complex (OGDHc) orchestrates a critical reaction regulating the TCA cycle. Although the structure of each OGDHc subunit has been solved, the architecture of the intact complex and inter-subunit interactions still remain unknown. Here we report the assembly of native, intact OGDHc from Sus scrofa heart tissue using cryo-electron microscopy (cryo-EM), cryo-electron tomography (cryo-ET), and subtomogram averaging (STA) to discern native structures of the whole complex and each subunit. Our cryo-EM analyses revealed the E2o cubic core structure comprising eight homotrimers at 3.3-Å resolution. More importantly, the numbers, positions and orientations of each OGDHc subunit were determined by cryo-ET and the STA structures of the core were resolved at 7.9-Å with 2024-01-01T00:00:00Z2024 Sep2026-06-01T10:05:21.211Z2025-04-04T08:22:17.455ZS-EPMC114367683933318610.1038/s41467-024-52792-7