H2O + L-glutamate + NAD(+) = 2-oxoglutarate + H(+) + NADH + NH4(+) Amino-acid degradation; L-glutamate degradation via hydroxyglutarate pathway; crotonoyl-CoA from L-glutamate: step 1/5. Homohexamer. Belongs to the Glu/Leu/Phe/Val dehydrogenases family.