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EC 1.4.1.21 Details
EC number
1.4.1.21
Accepted name
aspartate dehydrogenase
Reaction
L-aspartate + H2O + NAD(P)+ = oxaloacetate + NH3 + NAD(P)H + H+ (overall reaction);;(1a) L-aspartate + NAD(P)+ = 2-iminosuccinate + NAD(P)H + H+;;(1b) 2-iminosuccinate + H2O = oxaloacetate + NH3 (spontaneous)
Other name(s)
AspDH,
NAD-dependent aspartate dehydrogenase,
NADH2-dependent aspartate dehydrogenase,
NADP+-dependent aspartate dehydrogenase,
nadX (gene name),
L-aspartate:NAD(P)+ oxidoreductase (deaminating)
Systematic name
L-aspartate:NAD(P)+ oxidoreductase (2-iminosuccinate-forming)
CAS registry number
37278-97-0
Comment
The enzyme is strictly specific for L-aspartate as substrate. It produces the unstable compound 2-iminosuccinate, which, in the presence of water, hydrolyses spontaneously to form oxaloacetate. The enzyme from some archaea and thermophilic bacteria is likely to transfer 2-iminosuccinate directly to EC 2.5.1.72, quinolinate synthase, preventing its hydrolysis and enabling the de novo biosynthesis of NAD+.
History
created 2005, modified 2022
EC Tree
1.4.1.6 created 1961, deleted 1982