Cloning of an EF-P homologue from Bacteroides fragilis that increases B. fragilis glutamine synthetase activity in Escherichia coli

1998 ◽  
Vol 258 (4) ◽  
pp. 363-372 ◽  
Author(s):  
V. R. Abratt ◽  
M. Mbewe ◽  
D. R. Woods
Keyword(s):  
Escherichia Coli ◽  
Glutamine Synthetase ◽  
Bacteroides Fragilis ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity

scholarly journals Regulation of synthesis of glutamate dehydrogenase and glutamine synthetase in micro-organisms

1969 ◽  
Vol 115 (4) ◽  
pp. 769-775 ◽  
Author(s):  
J. A. Pateman
Keyword(s):  
Escherichia Coli ◽  
Glutamine Synthetase ◽  
Glutamate Dehydrogenase ◽  
Nitrogen Sources ◽  
Sole Source ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Escherichia Coli Cells ◽  
High Concentrations ◽  
Micro Organisms

1. Aspergillus nidulans, Neurospora crassa and Escherichia coli were grown on media containing a range of concentrations of nitrate, or ammonia, or urea, or l-glutamate, or l-glutamine as the sole source of nitrogen and the glutamate dehydrogenate and glutamine synthetase of the cells measured. 2. Aspergillus, Neurospora and Escherichia coli cells, grown on l-glutamate or on high concentrations of ammonia or on high concentrations of urea, possessed low glutamate dehydrogenase activity compared with cells grown on other nitrogen sources. 3. Aspergillus, Neurospora and Escherichia coli cells grown on l-glutamate possessed high glutamine synthetase activity compared with cells grown on other nitrogen sources. 4. The hypothesis is proposed that in Aspergillus, Neurospora and Escherichia colil-glutamate represses the synthesis of glutamate dehydrogenase and l-glutamine represses the synthesis of glutamine synthetase. 5. A comparison of the glutamine-synthesizing activity and the γ-glutamyltransferase activity of glutamine synthetase in Aspergillus and Neurospora gave no indication that these fungi produce different forms of glutamine synthetase when grown on ammonia or l-glutamate as nitrogen sources.

Cellular regulation of glutamine synthetase activity in Escherichia coli

1968 ◽  
Vol 6 ◽  
pp. 257-289 ◽  
Author(s):  
E.R. Stadtman ◽  
B.M. Shapiro ◽  
H.S. Kingdon ◽  
C.A. Woolfolk ◽  
J.S. Hubbard
Keyword(s):  
Escherichia Coli ◽  
Glutamine Synthetase ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Cellular Regulation

Respective effects of glucose and glutamine on the glutamine synthetase activity of human skin fibroblasts

1991 ◽  
Vol 102 (2) ◽  
Author(s):  
Th�ophile Soni ◽  
Claire Wolfrom ◽  
Samia Guerroui ◽  
Nicole Raynaud ◽  
Jos�phine Poggi ◽  
...  
Keyword(s):  
Glutamine Synthetase ◽  
Human Skin ◽  
Skin Fibroblasts ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Human Skin Fibroblasts

Control of nitrogen assimilation in Stichococcus bacillaris by growth conditions

1987 ◽  
Vol 65 (3) ◽  
pp. 432-437 ◽  
Author(s):  
Iftikhar Ahmad ◽  
Johan A. Hellebust
Keyword(s):  
Glutamine Synthetase ◽  
Nitrogen Assimilation ◽  
Continuous Light ◽  
Synthetase Activity ◽  
Glutamine Synthetase Activity ◽  
Dark Cycle ◽  
Continuous Darkness ◽  
Cell Carbon ◽  
Stichococcus Bacillaris ◽  
Mixotrophic Conditions

Stichococcus bacillaris Naeg. (Chlorophyceae) grown on a 12 h light: 12 h dark cycle divides synchronously under photoautotrophic conditions and essentially nonsynchronously under mixotrophic conditions. Photoassimilation of carbon under photoautotrophic conditions was followed by a decline in cell carbon content during the dark period, whereas under mixotrophic conditions cell carbon increased throughout the light–dark cycle. The rates of nitrogen assimilation by cultures grown on either nitrate or ammonium declined sharply during the dark, and these declines were most pronounced under photoautotrophic conditions. Photoautotrophic cells synthesized glutamine synthetase and NADPH – glutamate dehydrogenase (GDH) exclusively in the light, whereas in mixotrophic cells about 20% of the total synthesis of these enzymes during one light–dark cycle occurred in the dark. NADH–GDH was synthesized almost continuously over the entire light–dark cycle. In the dark, both under photoautotrophic and mixotrophic conditions, the alga contained more than 50% of glutamine synthetase in an inactive form, which was reactivated in vitro in the presence of mercaptoethanol and in vivo after returning the cultures to the light. The thermal stability of glutamine synthetase activity was less in light-harvested cells than in dark-harvested cells. The inactivation of glutamine synthetase did not occur in cultures growing either heterotrophically in continuous darkness or photoautotrophically in continuous light. This enzyme appears to be under thiol control only in cells grown under alternating light–dark conditions, irrespective of whether this light regime results in synchronous cell division or not.

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