The metabolic pathway of glutamate in escherichia coli K-12

Marcus, Menashe; Halpern, Yeheskel S.

doi:10.1016/0304-4165(69)90141-x

Cited by 48 publications

(44 citation statements)

References 11 publications

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“…(i) GItSEc transports L-glutamate in symport with at least two Na +. The involvement of Na ÷ in GItS-mediated transport has been suggested before (Frank and Hopkins, 1969;Kahane et aL, 1975;Marcus and Halpern, 1969;Miner and Frank, 1974;Schellenberg and Furlong, 1977), but in most of these studies a role of protons as alternative coupling ion MacDonald et aL, 1977;Tsuchiya et aL, 1977) or a symport of L-glutamate with Na ÷ plus H ÷ could not be excluded (Fujimura et aL, 1983a,b). By complementation of the E'.…”

Section: Discussionmentioning

confidence: 94%

Cation‐selectivity of the l‐glutamate transporters of Escherichia coli, Bacillus stearothermophilus and Bacillus caldotenax: dependence on the environment in which the proteins are expressed

Tolner

Ubbink-Kok

Poolman³

et al. 1995

Molecular Microbiology

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l‐Glutamate transport by the H+‐glutamate and Na+‐glutamate symport proteins of Escherichia coli K‐12 (GltPEc and GltSEc, respectively) and the Na+‐H+‐glutamate symport proteins of Bacillus stearothermophilus (GltTBs) and Bacillus caldotenax (GltTBc) was studied in membrane vesicles derived from cells in which the proteins were either homologously or heterologously expressed. Substrate and inhibitor specificity studies indicate that GltPEc, GltTBs and GltTBc fall into the same group of transporters, whereas GltSEc is distinctly different from the others. Also, the cation specificity of GltSEc is different; GltSEc transported l‐glutamate with (at least) two Na+, whereas GltPEc, GltTBs and GltTBc catalysed an electrogenic symport of l‐glutamate with ≥two H+, i.e. when the proteins were expressed in E. coli Surprisingly studies in membrane vesicles of B. stearothermophilus and B. caldotenax indicated a Na+‐H+‐l‐glutamate symport for both GltTBs and GltTBc. The Na+ dependency of the GltT transporters in the Bacillus strains increased with temperature. These observations suggest that the conformation of the transport proteins in the E. coli and the Bacillus membranes differs, which influences the coupling ion selectivity.

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Section: Discussionmentioning

confidence: 94%

Cation‐selectivity of the l‐glutamate transporters of Escherichia coli, Bacillus stearothermophilus and Bacillus caldotenax: dependence on the environment in which the proteins are expressed

Tolner

Ubbink-Kok

Poolman³

et al. 1995

Molecular Microbiology

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“…This necessitates the use of strains that express the transport system constitutively. These strains have mutations in the operator locus (gltC) that is adjacent to the glutamate permease structural gene (gltS) and they render permease synthesis insensitive to the gZtR-encoded repressor (Marcus & Halpern, 1969~). It is also observed that aspA mutants exhibit a pronounced tendency to revert on glutamate medium.…”

Section: Location and Isolation Of The Aspa Genementioning

confidence: 99%

“…The oxaloacetate that serves as the primary amino-acceptor is converted to aspartate and then regenerated by a 'deamination cycle' involving aspartase, fumarase and malate dehydrogenase. Thus, aspA and aspC mutants lacking either aspartase or aspartate aminotransferase are unable to grow on glutamate as the sole source of carbon and energy (Marcus & Halpern, 1969~). The importance of aspartate aminotransferase plus aspartase as an alternative route from oxaloacetate to fumarate and succinate during glucose fermentation was discovered in studies with malate dehydrogenase mutants and this role was supported by the observation that malate dehydrogenase is repressed whereas aspartase is derepressed during anaerobic growth (Courtright & Henning, 1970).…”

Section: Introductionmentioning

confidence: 98%

Cloning of the Aspartase Gene (aspA) of Escherichia coli

1984

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The aspartase gene (aspA) of Escherichiu coli has been isolated in two plasmids, pGS73 and pGS94, which contain segments of bacterial DNA (12.5 and 2.8 kb, respectively) inserted into the tet gene of the vector pBR322. The plasmids were constructed by sequential sub-cloning from a larger ColE1-frd+ hybrid plasmid. The location of the aspA gene confirmed predictions based on a correlation between the genetic and restriction maps of the corresponding region. The aspartase activities of plasmid-containing aspA mutants were amplified four-to sixfold relative to aspA+ parental strains. The aspA gene product was tentatively identified as a polypeptide of M , 55 000, which is somewhat larger than previous estimates ( M , 45 000 to 48 000) for aspartase.

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“…l ] was assayed using a modification of the method described by Halpern & Umbarger (1960) and Marcus & Halpern (1969). The assay system contained (in 3.0 ml): 200pmol phosphate buffer (pH 7.8); 1 pmol MgS04.7Hz0; 40 pmol potassium aspartate; and enzyme preparation.…”

Section: Introductionmentioning

confidence: 99%

The Enzymes of Ammonia Assimilation and their Control in Members of the Genus Erwinia

Pulman

Johnson

1978

Journal of General Microbiology

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The genus Erwinia is heterogeneous with respect to the presence of the ammonia assimilating enzymes glutamine synthetase (GS), NADP-linked glutamate synthase (GOGAT) and NADP-linked glutamate dehydrogenase. Three major groups were distinguished; one showed activity of all three enzymes, the second only GS and GOGAT activity and the third only GS activity. Aspartase did not appear to be significant in ammonia assimilation in any group.

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The metabolic pathway of glutamate in escherichia coli K-12

Cited by 48 publications

References 11 publications

Cation‐selectivity of the l‐glutamate transporters of Escherichia coli, Bacillus stearothermophilus and Bacillus caldotenax: dependence on the environment in which the proteins are expressed

Cation‐selectivity of the l‐glutamate transporters of Escherichia coli, Bacillus stearothermophilus and Bacillus caldotenax: dependence on the environment in which the proteins are expressed

Cloning of the Aspartase Gene (aspA) of Escherichia coli

The Enzymes of Ammonia Assimilation and their Control in Members of the Genus Erwinia

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