Member database | PRINTS |
PRINTS type | family |
Short name | HOLDHDRGNASE |
Description Imported from IPR012131
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
[1]. The reaction proceeds via a tightly- or covalently-bound inter-mediate, and requires the presence of 2 NAD molecules
[1]. By contrast with most dehydrogenases, the substrate is bound before the NAD coenzyme
[1]. A Cys residue has been implicated in the catalytic mechanism of the second oxidative step
[1].
In bacteria HDH is a single chain polypeptide; in fungi it is the C-terminal domain of a multifunctional enzyme which catalyses three different steps of histidine biosynthesis; and in plants it is expressed as nuclear encoded protein precursor which is exported to the chloroplast
[2].
References Imported from IPR012131
1.A cysteine residue (cysteine-116) in the histidinol binding site of histidinol dehydrogenase. Grubmeyer CT, Gray WR. Biochemistry 25, 4778-84, (1986). View articlePMID: 3533140
2.Structural and functional conservation of histidinol dehydrogenase between plants and microbes. Nagai A, Ward E, Beck J, Tada S, Chang JY, Scheidegger A, Ryals J. Proc. Natl. Acad. Sci. U.S.A. 88, 4133-7, (1991). View articlePMID: 2034659
Supplementary References
1. Cloning and characterization of the multifunctional his-3 gene of Neurospora crassa. Legerton TL, Yanofsky C. Gene 39, 129-40, (1985). View articlePMID: 3005109