Disease relevance of gdhA

• Complete nucleotide sequence of the Escherichia coli gdhA gene [1].
• Additionally, S. typhimurium gdhA DNA was shown to hybridize to single restriction fragments of chromosomes from other enteric bacteria and from Saccharomyces cerevisiae [2].
• Cloning and characterization of gdhA, the structural gene for glutamate dehydrogenase of Salmonella typhimurium [2].
• We cloned and sequenced the gene (gcd) encoding this enzyme and showed that the derived amino acid sequence is highly homologous to that of the gdhA gene product of Acinetobacter calcoaceticus [3].
• Glutamate dehydrogenase: genetic mapping and isolation of regulatory mutants of Klebsiella aerogenes [4].

High impact information on gdhA

• The glutamate dehydrogenase gene of Escherichia coli has been cloned into broad host-range plasmids and can complement glutamate synthase mutants of Methylophilus methylotrophus [5].
• Assimilation of ammonia via glutamate dehydrogenase is more energy-efficient than via glutamate synthase, thus the recombinant organism converts more growth substrate, methanol, into cellular carbon [5].
• In addition, they have glutamate synthase (EC 1.4.1.13) and glutamate dehydrogenase (EC 1.4.1.4) activities [6].
• In agreement with this reasoning we find the kinetics of glutamate accumulation to be independent of the specific path of synthesis, whether by glutamate dehydrogenase or by glutamate synthase [7].
• The nucleotide sequence of S. typhimurium gdhA was determined and the amino acid sequence derived [8].

Chemical compound and disease context of gdhA

• Lack of a regulatory function for glutamine synthetase protein in the synthesis of glutamate dehydrogenase and nitrite reductase in Escherichia coli K12 [9].
• A hybrid plasmid containing a fragment of the Salmonella typhimurium chromosome cloned into pBR328 restores growth of glutamate auxotrophs of S. typhimurium and Escherichia coli strains which have mutations in the genes for glutamate dehydrogenase and glutamate synthase [2].
• The possible role of glutamate dehydrogenase, glutamate synthase, and glutamine synthetase in the regulation of enzyme formation in the gamma-aminobutyric acid (GABA) catabolic pathway of Escherichia coli K-12 was investigated [10].
• The glutamine synthetase of Prevotella bryantii B(1)4 is a family III enzyme (GlnN) and glutamine supports growth of mutants lacking glutamate dehydrogenase activity [11].
• The NAD(P)H-utilizing glutamate dehydrogenase of Bacteroides thetaiotaomicron belongs to enzyme family I, and its activity is affected by trans-acting gene(s) positioned downstream of gdhA [12].

Biological context of gdhA

• Glutamate dehydrogenase encoded by gdhA carried on recombinant plasmids was elevated 5- to over 100-fold in S. typhimurium or E. coli cells and was regulated in both organisms [2].
• Finally, possible regulatory sequences located at the 5' flanking region of the gdhA gene are discussed [13].
• The complete nucleotide sequence of the Escherichia coli gdhA gene, as well as its 5' and 3' flanking regions have been previously reported [Valle et al., Gene 23 (1983) 199-209; 27 (1984) 193-199] [13].
• The use of the gdhA promoter for homologous and heterologous gene expression in fungi and Escherichia coli was analyzed [14].
• The gdhA gene was found to be present in a single copy in the genome of several P. chrysogenum strains with different penicillin productivity [14].

Anatomical context of gdhA

• These data suggest that the gdhA transgene began degradation in the stomach and was nondetectable in the large intestine [15].
• The remaining 56 pigs were transitioned onto a corn-soybean meal diet and fed a diet containing 58% gdhA corn for approximately 1 wk; immediately thereafter, liver, 10th rib muscle, white blood cells, and plasma from the hepatic portal vein and ingesta from the stomach, distal ileum, and large intestine were collected [15].
• A site-directed mutant of clostridial glutamate dehydrogenase in which Ala163 in the glutamate binding site is replaced by glycine displays a markedly sigmoid dependence of reaction rate on glutamate concentration (S0.5 = 200 mM), with a Hill coefficient of 3.4 when assayed at pH 10.5 with 1 mM NAD+ [16].
• Blood samples were collected and analysed for hematology and total serum bile acids (S-BA), glutamate dehydrogenase (S-GLDH), calcium (S-Ca), iron (S-Fe), zinc (S-Zn) and a blood plasma metabolite (15-ketodihydro-PGF2a; P-PG) of prostaglandin F2a [17].

Associations of gdhA with chemical compounds

• The gdhA gene encoding the NADP-dependent glutamate dehydrogenase activity from Penicillium chrysogenum has been isolated and characterized for its use in gene expression [14].
• The gdhA1 mutational site has been identified by recombinational mapping, polymerase chain reaction (PCR) amplification and DNA sequencing, as an A to G transition at nucleotide 274 of the gdhA coding sequence, resulting in an amino acid change of lysine 92 to glutamic acid [18].
• The higher state of GS is connected with a lower GDH activity and NH3 concentration [19].
• Gene expression of GOGAT above a threshold value makes expression of GS under ammonium-limited conditions, and of GDH under glucose-limited conditions, sufficient for ammonium assimilation [20].
• Cause and effect between gdhA expression, glutamate metabolism, and plant phenotypes was analyzed by (13) NH(4)(+) labeling of amino acid fractions, and by FT-ICR-MS analysis of metabolites [21].

Regulatory relationships of gdhA

• Since no adenylation of the GS is detectable GS bistability seems to be regulated on the level of enzyme synthesis like GDH bistability [19].

Other interactions of gdhA

• In wild-type bacteria there was only a weak inverse correlation between the activities of GS and glutamate dehydrogenase (GDH) during growth in various media [9].
• The argP mutation, but not the glnE mutation, was associated with reduced glutamate dehydrogenase activity and a concomitant NH4+ assimilation defect in the gltBD strain [22].

Analytical, diagnostic and therapeutic context of gdhA

• A pBR322-derived plasmid (pCGL107) that carries the Corynebacterium melassecola ATCC17965 analogue of Escherichia coli gdhA gene (encoding glutamate dehydrogenase), was introduced into the related strain, Brevibacterium lactofermentum CGL2002, by electroporation and integrated into its chromosome by homologous recombination [23].
• Polymerase chain reaction and gel electrophoresis were performed with primers designed to amplify 490 bp that included the plasmid's ligation site between the maize ubiquitin and the gdhA genes [15].
• Northern blot analysis with a gdhA-specific probe indicated that a single transcript with an electrophoretic mobility of approximately 1.6 kb was produced in both B. thetaiotaomicron and E. coli gdhA+ transformants [12].
• Crystallization of the NADP(+)-dependent glutamate dehydrogenase from Escherichia coli [24].
• The NADP(+)-dependent hexameric glutamate dehydrogenase from Escherichia coli has been crystallized as the apo-enzyme and also in the presence of its substrates 2-oxoglutarate, glutamate or NADP+, using either pulsed equilibrium microdialysis, or the hanging drop method of vapour diffusion [24].

References