H2O + L-glutamate + NAD(+) = 2-oxoglutarate + H(+) + NADH + NH4(+) Activity is stimulated by AMP. (Microbial infection) Inhibited by ADP-ribosylation. Optimum pH is 7.25-7.5. Homodimer. (Microbial infection) ADP-ribosylated at Arg-763 by the Legionella pneumophila effector Lart1, which inhibits the glutamate dehydrogenase activity. Amoeba are natural hosts of Legionella, and ADP-ribosylation by Lart1 may promote Legionella parasitism. Belongs to the Glu/Leu/Phe/Val dehydrogenases family.