Aldehyde dehydrogenase, N-terminal <p>This entry represents a structural domain found at the N-terminal of aldehyde dehydrogenases [<cite idref="PUB00022295"/>]. These proteins contain two similar domains, each with a 3-layer alpha/beta/alpha structure, which probably arose from a duplication; this entry covers the N-terminal a/b/a domain. These enzymes binds NAD differently from other NAD(P)-dependent oxidoreductases. </p><p>Aldehyde dehydrogenases (<db_xref db="EC" dbkey="1.2.1.3"/> and <db_xref db="EC" dbkey="1.2.1.5"/>) are enzymes that oxidize a wide variety of aliphatic and aromatic aldehydes using NADP as a cofactor. In mammals at least four different forms of the enzyme are known [<cite idref="PUB00000303"/>]: class-1 (or Ald C) a tetrameric cytosolic enzyme, class-2 (or Ald M) a tetrameric mitochondrial enzyme, class- 3 (or Ald D) a dimeric cytosolic enzyme, and class IV a microsomal enzyme. Aldehyde dehydrogenases have also been sequenced from fungal and bacterial species. A number of enzymes are known to be evolutionary related to aldehyde dehydrogenases. A glutamic acid and a cysteine residue have been implicated in the catalytic activity of mammalian aldehyde dehydrogenase.</p>