| Type: | Domain | Name: | Aldehyde/histidinol dehydrogenase |
| Description: | This entry represents a structural domain found in aldehyde dehydrogenases [] and histidinol dehydrogenases []. These proteins contain two similar domains, each with a 3-layer alpha/beta/alpha structure, which probably arose from a duplication. These enzymes bindNAD differently from other NAD(P)-dependent oxidoreductases. Aldehyde dehydrogenases (and ) 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 []: 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.Histidinol dehydrogenase () (HDH) catalyses the terminal step in the biosynthesis of histidine in bacteria, fungi, and plants, the four-electron oxidation of L-histidinol to histidine. In 4-electron dehydrogenases, a single active site catalyses 2 separate oxidation steps: oxidation of the substrate alcohol to an intermediate aldehyde; and oxidation of the aldehyde to the product acid, in this case His []. The reaction proceeds via a tightly- or covalently-bound inter-mediate, and requires the presence of 2 NAD molecules []. By contrast with most dehydrogenases, the substrate is bound before the NAD coenzyme []. A Cys residue has been implicated in the catalytic mechanism of the second oxidative step []. In bacteria HDH is a single chain polypeptide; in fungi it is the C-terminal domain of a multifunctional enzyme which catalyzes three different steps of histidine biosynthesis; and in plants it is expressed as nuclear encoded protein precursor which is exported to the chloroplast []. | Short Name: | Ald_DH/histidinol_DH |
| DB identifier | Type | Name |
|---|---|---|
| IPR016163 | Domain | Aldehyde dehydrogenase, C-terminal |
| IPR016162 | Domain | Aldehyde dehydrogenase N-terminal domain |
| IPR001692 | Conserved_site | Histidinol dehydrogenase, conserved site |
| IPR020593 | Conserved_site | Gamma-glutamyl phosphate reductase GPR, conserved site |
| IPR016160 | Conserved_site | Aldehyde dehydrogenase, cysteine active site |
| GO Term | Gene Name |
|---|---|
| GO:0016491 | IPR016161 |
| GO:0008152 | IPR016161 |
| GO:0055114 | IPR016161 |
