|Gene:||gdhA||Accession Number: G-8963 (MetaCyc)|
Species: Halobacterium salinarum
Subunit composition of
glutamate dehydrogenase (NAD-dependent) = [GdhA]6
NAD-glutamate dehydrogenase subunit = GdhA
Halobacterium salinarum is one of the organisms reported to have more than one form of GDH, with different forms utilizing different cofactors (NAD and NADP) [Bonete89, Bonete90]. It was eventually shown that the organism has four genes encoding four different glutamate dehydrogenase enzymes [Ingoldsby05]. Two of these gene products have been purified and characterized biochemically [Bonete96a, PerezPomares99]. One of the genes, gdhA1, which was originally predicted to encode an NADP-specific form [Benachenhou91], was found to encode an NAD-specific enzyme, suggesting that sequence information alone in not sufficient to predict the cofator specificity of GDH [Ingoldsby05].
Molecular Weight of Polypeptide: 59.0 kD (experimental) [PerezPomares99 ]
Relationship Links: Entrez-Nucleotide:PART-OF:X63837
Enzymatic reaction of: glutamate dehydrogenase (NAD-dependent)
Synonyms: glutamic dehydrogenase, L-glutamate:NAD+ oxidoreductase (deaminating)
EC Number: 126.96.36.199
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.
This reaction is reversible.
In Pathways: glutamate degradation I
Activators (Unknown Mechanism): L-glutamine [Bonete96a] , L-asparagine [Bonete96a] , L-aspartate [Bonete96a] , L-histidine [Bonete96a] , L-arginine [Bonete96a] , L-lysine [Bonete96a] , L-phenylalanine [Bonete96a] , L-tyrosine [Bonete96a] , L-tryptophan [Bonete96a] , L-cysteine [Bonete96a] , L-methionine [Bonete96a] , L-threonine [Bonete96a] , L-serine [Bonete96a] , L-isoleucine [Bonete96a] , L-leucine [Bonete96a] , L-valine [Bonete96a] , L-alanine [Bonete96a] , glycine [Bonete96a]
Inhibitors (Noncompetitive): NADP+ [Bonete96a, Comment 4] , oxaloacetate [Bonete96a, Comment 5] , succinate [Bonete96a, Comment 6] , (S)-malate [Bonete96a, Comment 7] , fumarate [Bonete96a, Comment 8] , L-glutamate [Bonete89, Comment 9]
Benachenhou91: Benachenhou N, Baldacci G (1991). "The gene for a halophilic glutamate dehydrogenase: sequence, transcription analysis and phylogenetic implications." Mol Gen Genet 230(3);345-52. PMID: 1766432
Bonete96a: Bonete MJ, Perez-Pomares F, Ferrer J, Camacho ML (1996). "NAD-glutamate dehydrogenase from Halobacterium halobium: inhibition and activation by TCA intermediates and amino acids." Biochim Biophys Acta 1996;1289(1);14-24. PMID: 8605224
Ingoldsby05: Ingoldsby LM, Geoghegan KF, Hayden BM, Engel PC (2005). "The discovery of four distinct glutamate dehydrogenase genes in a strain of Halobacterium salinarum." Gene 349;237-44. PMID: 15780999
PerezPomares99: Perez-Pomares F, Ferrer J, Camacho M, Pire C, LLorca F, Bonete MJ (1999). "Amino acid residues involved in the catalytic mechanism of NAD-dependent glutamate dehydrogenase from Halobacterium salinarum." Biochim Biophys Acta 1999;1426(3);513-25. PMID: 10076069
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