A flavoprotein and iron sulfur-containing oxidoreductase complex that catalyzes the conversion of UBIQUINONE to ubiquinol. In MITOCHONDRIA the complex also couples its reaction to the transport of PROTONS across the internal mitochondrial membrane. The NADH DEHYDROGENASE component of the complex can be isolated and is listed as EC 1.6.99.3. (mesh:D042967)
| Identifier | Name | Relation |
| FPLX:ETC_complex_I_core | ETC_complex_I_core | partof |
| FPLX:ETC_complex_I_supernumerary | ETC_complex_I_supernumerary | partof |