<p>Glutamate, leucine, phenylalanine and valine dehydrogenases are structurally and functionally related. They contain a Gly-rich region containing a conserved Lys residue, which has been implicated in the catalytic activity, in each case a reversible oxidative deamination reaction.</p><p>Glutamate dehydrogenases (<db_xref db="EC" dbkey="1.4.1.2"/>, <db_xref db="EC" dbkey="1.4.1.3"/>, and <db_xref db="EC" dbkey="1.4.1.4"/>) (GluDH) are enzymes that catalyse the NAD- and/or NADP-dependent reversible deamination of L-glutamate into alpha-ketoglutarate [<cite idref="PUB00001430"/>, <cite idref="PUB00003424"/>]. GluDH isozymes are generally involved with either ammonia assimilation or glutamate catabolism. Two separate enzymes are present in yeasts: the NADP-dependent enzyme, which catalyses the amination of alpha-ketoglutarate to L-glutamate; and the NAD-dependent enzyme, which catalyses the reverse reaction [<cite idref="PUB00002418"/>] - this form links the L-amino acids with the Krebs cycle, which provides a major pathway for metabolic interconversion of alpha-amino acids and alpha- keto acids [<cite idref="PUB00004656"/>].</p><p>Leucine dehydrogenase (<db_xref db="EC" dbkey="1.4.1.9"/>) (LeuDH) is a NAD-dependent enzyme that catalyses the reversible deamination of leucine and several other aliphatic amino acids to their keto analogues [<cite idref="PUB00000302"/>]. Each subunit of this octameric enzyme from <taxon tax_id="1421">Bacillus sphaericus</taxon> contains 364 amino acids and folds into two domains, separated by a deep cleft. The nicotinamide ring of the NAD+ cofactor binds deep in this cleft, which is thought to close during the hydride transfer step of the catalytic cycle.</p><p>Phenylalanine dehydrogenase (<db_xref db="EC" dbkey="1.4.1.20"/>) (PheDH) is na NAD-dependent enzyme that catalyses the reversible deamidation of L-phenylalanine into phenyl-pyruvate [<cite idref="PUB00002347"/>].</p><p>Valine dehydrogenase (<db_xref db="EC" dbkey="1.4.1.8"/>) (ValDH) is an NADP-dependent enzyme that catalyses the reversible deamidation of L-valine into 3-methyl-2-oxobutanoate [<cite idref="PUB00002221"/>].</p><p>This entry represents the C-terminal domain of these proteins.</p> Glutamate/phenylalanine/leucine/valine dehydrogenase, C-terminal