Enzyme - Aspartate-semialdehyde dehydrogenase

Alternative Name(s)
  • ASA dehydrogenase.
  • L-aspartate-beta-semialdehyde dehydrogenase.
  • Aspartic semialdehyde dehydrogenase.

Catalytic Activity

L-aspartate 4-semialdehyde + NADP(+) + phosphate = 4-phospho-L-aspartate + H(+) + NADPH


There are no Cofactors for this Enzyme

Reaction Mechanism

    Aspartate-beta-semialdehyde dehydrogenase (ASADH) lies at the first branch point in the biosynthetic pathway that converts L-aspartic acid to lysine, isoleucine, methionine, threonine and metabolic intermediates such as diaminopimelic acid. The reaction catalysed is the reductive dephosphorylation of L-beta-aspartyl phosphate to L-aspartate-beta-semialdehyde, in the presence of NADPH. ASADH occurs in plants, most bacteria and fungi.

    The mechanism of ASADH is thought to be very similar to that of Glyceraldehyde-3-phosphate dehydrogenase. In the suggested mechanism the cysteine thiolate attacks the substrate carbonyl to form a thioester intermediate. This is followed by the transfer of a hydride to NADP to form NADPH. The oxygen anion of a bound inorganic phosphate attacks the thioester intermediate to expel the cysteine thiolate and to form the phosphorylated product.
    Catalytic Residues
    AA Uniprot Uniprot Resid PDB PDB Resid
    His P0A9Q9 274 1brm 274
    Arg P0A9Q9 267 1brm 267
    Cys P0A9Q9 135 1brm 135
    Gln P0A9Q9 162 1brm 162

Reaction Parameters

There are no kinetic parameters information for this Enzyme

Associated Proteins

Protein name Organism
Aspartate-semialdehyde dehydrogenase Escherichia coli (strain K12)
Aspartate-semialdehyde dehydrogenase 1 Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961)
Probable aspartate-semialdehyde dehydrogenase Fission yeast
Aspartate-semialdehyde dehydrogenase 2 Vibrio cholerae serotype O1 (strain ATCC 39315 / El Tor Inaba N16961)
Aspartate Dehydrogenase Chlamydia pneumoniae