2-oxoglutarate dehydrogenase (E1-like) component of the 2-oxoglutarate dehydrogenase multienzyme complex (OGDHC) which mediates the decarboxylation of alpha-ketoglutarate in the tricarboxylic acid cycle. The OGDHC complex catalyzes the overall conversion of 2-oxoglutarate to succinyl-CoA and CO(2) while reducing NAD(+) to NADH (By similarity). The OGDHC complex is mainly active in the mitochondrion (By similarity). Involved in the inhibition of cell proliferation and in apoptosis (PubMed:23152800, PubMed:31175094).