Disease relevance of gltA

• Nucleotide sequence of the promoter region of the citrate synthase gene (gltA) of Escherichia coli [1].
• The transcripts of the citrate synthase-encoding gene (gltA) in Rickettsia prowazekii (Rp), an obligate intracellular parasitic bacterium, were analyzed by RNase protection (RP), primer extension (PE) and in vitro transcription assays [2].
• A fragment of DNA (3.1 kilobases [kb]) from a ColE1 Escherichia coli DNA hybrid plasmid containing the bacterial citrate synthase gene (gltA) was subcloned in both orientations into phage lambda vectors by in vitro recombination [3].
• The gltA gene, encoding Sinorhizobium meliloti 104A14 citrate synthase, was isolated by complementing an Escherichia coli gltA mutant [4].
• Nitrogen source regulation of glutamate synthase activity in Bacillus subtilis occurs at the level of transcription of the gltA and gltB genes, which encode the two subunits of the enzyme [5].

High impact information on gltA

• The gene for the matrix enzyme citrate synthase was sequenced; the derived amino acid sequence of the precursor polypeptide revealed an amino-terminal extension containing basic but no acidic residues [6].
• Sodium dodecyl sulfate/polyacrylamide gel analysis of polypeptides produced by minicells containing the citrate synthase-complementing recombinant molecules demonstrated the production of a 46-kDa polypeptide [7].
• In contrast, when glucose was the main nutrient, the same underproduction of citrate synthase had little effect on either growth or carbon flux [8].
• When acetate was the sole carbon source, cell growth and carbon flow through the Krebs cycle were greatly affected by the under-production of citrate synthase [8].
• Probing the roles of key residues in the unique regulatory NADH binding site of type II citrate synthase of Escherichia coli [9].

Chemical compound and disease context of gltA

• The T. ferrooxidans and E. coli citrate synthases shared 37% amino acid sequence identity and the cloned T. ferrooxidans citrate synthase gene was able to complement an E. coli gltA mutant [10].
• The role of cysteine 206 in allosteric inhibition of Escherichia coli citrate synthase. Studies by chemical modification, site-directed mutagenesis, and 19F NMR [11].
• The level of citrate synthase was varied in Escherichia coli by recombinant DNA methods to elucidate regulatory interactions between the individual steps of the citric acid cycle [12].
• Thus, acetylcoenzyme A binding to type II E. coli citrate synthase would require substantial structural shifts and a concerted refolding of the polypeptide chain to form an appropriate binding subsite [13].
• Using existing restriction sites in the cloned E. coli citrate synthase gene, we prepared a deletion mutant which lacked 24 amino acids near what is predicted to the acetyl-CoA-binding portion of the active site [14].

Biological context of gltA

• Finally, gltA-lacZ expression was shown to be inversely proportional to the cell growth rate [15].
• The Sdh-encoding gene cluster (sdhCDAB) begins 3326 bp upstream from the citrate synthase-encoding gene (gltA) start codon and is read with opposite polarity [16].
• Regulation of the citrate synthase (gltA) gene of Escherichia coli in response to anaerobiosis and carbon supply: role of the arcA gene product [15].
• Determination of its N-terminal amino acid sequence demonstrates that the mutant citrate synthase is encoded by a gene distinct from the E. coli gltA gene [17].
• Escherichia coli possesses a hexameric citrate synthase that exhibits allosteric kinetics and regulatory sensitivity, and for which the gene (gltA) has previously been cloned and sequenced [17].

Associations of gltA with chemical compounds

• Together with the iron-sulphur protein gene (sdhB) these genes form an operon (sdhCDAB) situated between the citrate synthase gene (gltA) and the 2-oxoglutarate dehydrogenase complex genes (sucAB): gltA-sdhCDAB-sucAB [18].
• Whereas the hexameric citrate synthase is constitutively produced, the 2-methylcitrate synthase is induced during growth on propionate, and the catabolism of propionate to succinate and pyruvate via 2-methylcitrate is proposed [19].
• The S. meliloti gltA gene was mutated by inserting a kanamycin resistance gene and then using homologous recombination to replace the wild-type gltA with the gltA::kan allele [4].
• The gltA gene encoding a glutamate synthase (GOGAT) from the hyperthermophilic archaeon Pyrococcus sp. KOD1 was cloned as a 6.6 kb HindIII-BamHI fragment [20].
• We propose that the fluorine label in wild type citrate synthase exists in two conformational states with different mobilities, exchanging slowly on the NMR time scale, and that treatment with KCl, or truncation of the Glu-207 side chain by mutagenesis, stabilizes one of these states [11].

Regulatory relationships of gltA

• When citrate synthase was overproduced the isocitrate dehydrogenase reaction became rate limiting and prevented large increases in the flux through the citric acid cycle [12].

Other interactions of gltA

• Knocking out ppc or gltA decreased the maximum cell density by 14% and increased the acetate excretion by 7%, respectively decreased it by 10% [21].
• The enzyme activities of both ICDH, found to be NAD+ dependent, and citrate synthase were measured in cell extracts of wild-type S. mutans and E. coli mutants harboring plasmid pJG400 [22].
• Genetic and biochemical analyses of the mutant revealed the downregulation of many TCA cycle enzymes, including citrate synthase, and the upregulation of the pyruvate dehydrogenase complex in both transcription and enzyme activities [23].
• The residual citrate synthase activity was purified from a citA null mutant strain, and the partial amino acid sequence for the purified protein (CitZ) was determined [24].

Analytical, diagnostic and therapeutic context of gltA

• All citrate synthase activity in G. sulfurreducens could be resolved to a single 49-kDa protein via affinity chromatography [25].
• Oligonucleotides specific for B. henselae gltA were evaluated for the ability to prime PCR amplification within the alpha and gamma branches of the proteobacteria [26].
• DEAE-cellulose chromatography of P. aeruginosa citrate synthase from an E. coli host harboring the cloned P. aeruginosa gene gave three peaks of activity [27].

References