The oxoglutarate dehydrogenase complex catalyses the conversion of 2-oxoglutarate into succinyl-CoA in the tricarboxylic acid cycle, thereby fulfilling crucial functions in mitochondria by providing metabolites and reduced electron carriers for oxidative phosphorylation. It is a giant enzyme cluster composed of multiple copies of three subunits. The dihydrolipoyllysine-residue succinyltransferase subunit (DLST, also known as E2) serves as a structural core unit. The OGDH (also known as E1) and dihydrolipoyl dehydrogenase (DLD, also known as E3) subunits sit in the periphery of the E2 core. The OGDH subunit recognizes the 2-oxoglutarate substrate and provides specificity to the complex. (Adapted from FBrf0256925.)
Notes on Group
The OGDH subunit is encoded by two paralogous genes in D. melanogaster: Ogdh1 is expressed ubiquitously whereas Ogdh2 is testis-specific.