Glutamine Synthetase of Escherichia

Glutamine Synthetase of Escherichia coli. Some Physical and Chemical Properties Ann Ginsburg... 

Cervera and Levine [81] studied the mechanism of oxidative modification of glutamine synthetase from Escherichia coli. It was found that active oxygen species initially caused inactivation of the enzyme and generated a more hydrophilic protein, which still was not a substrate for the protease. Continuous action of oxygen species resulted in the formation of oxidized protein subjected to the proteolytic attack of protease. 

Woolfolk, C. A. Stadtman, E. R. (1967). Regulation of glutamine synthetase III. Cumulative feedback inhibition of glutamine synthetase from Escherichia coli. Arch. Biochem. Biophys. 118,736-755. 

Experimental demonstration that the Escherichia coli glutamine synthetase reaction operates by a random order of addition of substrates and a random order of release of products. 

Homogeneous preparations of glutamine synthetase are available from many sources including Escherichia coli, Salmonella typhimurium, peas, sheep brain, and rat liver. Glutamine synthetases from bacteria have 12... 

Escherichia coli have also developed an elegant method to control enzyme catalysis that occurs by covalent modification of each subunit. In this latter reaction a single tyrosyl residue per subunit is adenylylated to produce a stable 5 -adenylyl-O-tyrosyl derivative. Recent NMR and fluorescence data will be reviewed concerning the nature of this adenylyl site and its spatial relationship to the metal ions at the catalytic site. The enzymes responsible for the covalent adenylylation reaction comprise a cascade system for amplifying the activation or inactivation of glutamine synthetase molecules (81). 

Stadtman, E. R., Smymiotis, P. Z., Davis, T. N., and Wittenberger, M. E. (1979). Enzymatic procedures for determining the average state ofadenylylation of Escherichia coli glutamine synthetase. Anal. Biochem. 95, 275—285. 

S.G. Rhee, P.B. Chock, and E.R. Stadtman. 1989. Regulation of Escherichia coli glutamine synthetase Enzymol. Mol. Biol. 62 37-92. (PubMed)... 

Recent primary structure sequence studies on Escherichia colt glutamine synthetase demonstrated that the covalently bound active site adenylic acid residue is attached to a tyrosine residue (235). The sequence of amino acids around the derivated tyrosine residue is ... 

Feng, J., Atkinson, M.R., McGleary, W, Stock, J.B., Wanner, B.L. and Nrnfa, A.J. (1992). Role of phosphorylated metabolic intermediates in the regulation of glutamine synthetase synthesis in Escherichia coli. J. Bacteriol. 174, 6061-6070. 

Effects on Catalytic Activity of Escherichia coli Glutamine Synthetase Caused by Site-Specific Transferase A-Catalyzed ADP-Ribosylation... 

Fig. S. Depiction of the active site of Escherichia coli glutamine synthetase showing the n, and 2 metal-ion sites and the probable location of the nucleotide when Cr + (A) or Mn + (B) is the divalent cation.

Carbamoyl phosphate synthesis from ammonia represents one of the prominent activities in ureotelic livers [78]. The enzyme requires N-acetylglutamate and is distinct from the enzyme responsible for carbamoyl phosphate synthesis in extrahepatic tissues and in the livers of uricotelic animals. This second enzyme utilizes glutamine [79], rather than ammonia as the primary nitrogen donor and is found in mushrooms, Escherichia coli, yeast, Ehrlich ascites tumour and several other animal tissues [80]. This enzyme is carbamoyl phosphate synthetase II (ATP carbamate phosphotransferase, EC 2.7.2.2) and catalyses the following reaction ... 

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