2-oxoglutarate + H(+) + N(6)-((R)-lipoyl)-L-lysyl-(dihydrolipoyllysine-residue succinyltransferase) => CO2 + N(6)-((R)-S(8)-succinyldihydrolipoyl)-L-lysyl-(dihydrolipoyllysine-residue succinyltransferase),
Oxidative decarboxylation of alpha-ketoglutarate to succinyl CoA by alpha-ketoglutarate dehydrogenase