The 2-oxoglutarate dehydrogenase complex catalyzes the overall conversion of 2-oxoglutarate to succinyl-CoA and CO(2). It contains multiple copies of three enzymatic components: 2-oxoglutarate dehydrogenase (E1), dihydrolipoamide succinyltransferase (E2) and lipoamide dehydrogenase (E3) (By similarity). (R)-N(6)-dihydrolipoyl-L-lysyl-[2-oxoglutarate dehydrogenase complex component E2] + succinyl-CoA = (R)-N(6)-(S(8)-succinyldihydrolipoyl)-L-lysyl-[2-oxoglutarate dehydrogenase complex component E2] + CoA Binds 1 lipoyl cofactor covalently. Amino-acid degradation; L-lysine degradation via saccharopine pathway; glutaryl-CoA from L-lysine: step 6/6. Forms a 24-polypeptide structural core with octahedral symmetry. May be due to an intron retention. Belongs to the 2-oxoacid dehydrogenase family. Truncated N-terminus.