Description | This superfamily represents the FMN-binding domain for NADH-ubiquinone oxidoreductase 51kDa subunit from NADH:ubiquinone oxidoreductase. Its structure is composed of three layers (α/β/α) with a parallel β-sheet of four strands.NADH:ubiquinone oxidoreductase (complex I) ( ) is a respiratory-chain enzyme that catalyses the transfer of two electrons from NADH to ubiquinone in a reaction that is associated with proton translocation across the membrane (NADH + ubiquinone = NAD+ + ubiquinol) [ ]. Complex I is a major source of reactive oxygen species (ROS) that are predominantly formed by electron transfer from FMNH(2). Complex I is found in bacteria, cyanobacteria (as a NADH-plastoquinone oxidoreductase), archaea [], mitochondria, and in the hydrogenosome, a mitochondria-derived organelle. In general, the bacterial complex consists of 14 different subunits, while the mitochondrial complex contains homologues to these subunits in addition to approximately 31 additional proteins [].Among the many polypeptide subunits that make up complex I, there is one with a molecular weight of 51kDa (in mammals), which is the second largest subunit of complex I [ ]. The 51kDa subunit, as the corresponding bacterial subunit (Nqo1 in Thermus and NuoF in E. coli) [ ], contains the NADH-binding site, the primary electron acceptor FMN-binding site, and a 4Fe-4S cluster []. | Name | NADH-ubiquinone oxidoreductase 51kDa subunit, FMN-binding domain superfamily |
Short Name | Nuo51_FMN-bd_sf | Type | Homologous_superfamily |