Glutamine synthetase/synthase

See specific aminotransferase Glutamate as a substrate or product, GLUTAMATE DECARBOXYLASE GLUTAMATE DEHYDROGENASE GLUTAMATE SYNTHASE GLUTAMINE SYNTHETASE y-GLUTAMYL TRANSPEPTIDASE LEUCINE AMINOTRANSEERASE LYSINE 6-AMINOTRANSEERASE... 

The net reaction of glutamine synthetase and glutamate synthase (Eqns 22-1 and 22-2) is... 

Terms in bold are defined in the nitrogen cycle 834 nitrogen fixation 834 symbionts 834 nitrogenase complex 835 leghemoglobin 836 glutamine synthetase 838 glutamate synthase 838 glutamine amidotransferases 840 5-phosphoribosyl-l-... 

Fig. 1. The nitrate assimilation pathway in higher plants. The pathway of nitrate assimilation in the tobacco leaf is illustrated. In some other species an additional cytosolic GS is found in the leaf. The pathway in plant roots is more poorly documented and more variable GS in roots is mostly cytosolic, and some enzymes such as GOGAT are found as isoforms utilising alternate reducing substrates. T, expected nitrate carrier NR, nitrate reductase NiR, nitrite reductase GS, glutamine synthetase GOGAT, glutamate synthase Fd, ferredoxin Gin, glutamine Glu, glutamate.

Chen, F.-L., Bennett, M.J. Cullimore, J.V. (1990). Effect of the nitrogen supply on the activities of isoenzymes of NADH-dependent glutamate synthase and glutamine synthetase in root nodules of Phaseolus vulgaris L. Journal of Experimental Botany 41, 1215-21. 

Glutamine synthetase catalyzes the incorporation of ammonia into glutamine, deriving energy from the hydrolysis of ATP (Fig. 3b). This enzyme is named a synthetase, rather than a synthase, because the reaction couples bond formation with the hydrolysis of ATP. In contrast, a synthase does not require ATP. 

Berger, M.G., Sprengart, M.L., Kusnan, M. and Fock, H.P. (1986) Ammonia fixation via glutamine synthetase and glutamate synthase in the crassulacean acid metabolism plant, Cissus quadrangularis. Plant Physiol., 81, 356-60. 

Wang, R. and Nicholas, D.J.D. (1985) Some properties of glutamine synthetase and glutamate synthase from Derxia gummosa. Phytochemistry, 24,1133-40. 

Baron, A. C., Tobin, T. H., WaHsgrove, R. M., and Tobin, A. K. (1994). AmetaboHc control analysis of the glutamine synthetase/glutamate synthase cycle in isolated barley Elordeum vulgare L.) chloroplasts. Plant Physiol. 105, 415-424. 

Figure 11 Nitrogen sources and metabolic pathways in marine phytoplankton. Solid circles are transporters. Boxes are the catalytic enzymes and open circles are metals associated with each enzyme. Ur, Urease NR, Nitrate Reductase NiR, Nitrite Reductase AAOx, amino acid oxidase AmOx, amine oxidase GS-GOGAT, Glutamine Synthetase- Glutamate oxy-glutarate aminotransferase (or glutamate synthase).

Yeldandi AV, Tan X, Dwivedi RS, et al. 1990. Coexpression of glutamine synthetase and carbamoylphosphate synthase I genes in pancreatic hepatocytes of rat. Proc Natl Acad Sci U S A 87(3) 881-885. 

Figure 11. Time course of the destruction of heterocysts and solubilization of the activities of glutamine synthetase and glutamate synthase during sonic cavitation of N2 -groton A. cylindrica the number of...

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