Conserved Site

Histidinol dehydrogenase, conserved site (IPR001692)

Short name: Histidinol_DH_CS

Description

Histidinol dehydrogenase (EC:1.1.1.23) (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 [PMID: 3533140]. The reaction proceeds via a tightly- or covalently-bound inter-mediate, and requires the presence of 2 NAD molecules [PMID: 3533140]. By contrast with most dehydrogenases, the substrate is bound before the NAD coenzyme [PMID: 3533140]. A Cys residue has been implicated in the catalytic mechanism of the second oxidative step [PMID: 3533140].

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 [PMID: 2034659].

GO terms

Biological Process

GO:0000105 histidine biosynthetic process
GO:0055114 oxidation-reduction process

Molecular Function

GO:0004399 histidinol dehydrogenase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns