Involved in the anaerobic fermentation of lysine. Catalyzes the oxidative deamination of L-erythro-3,5-diaminohexanoate (3,5-DAH) to 3-keto-5-aminohexanoate (KAH). (3S,5S)-3,5-diaminohexanoate + H2O + NAD(+) = (5S)-5-amino-3-oxohexanoate + H(+) + NADH + NH4(+) Amino-acid degradation; L-lysine degradation via acetate pathway. Homodimer. Belongs to the KDD family.