Role of glutamine as a direct co-repressor of glutamine synthetase in Rhodobacter capsulatus E1F1.
High performance liquid chromatography (HPLC) has been used to determine the internal levels of amino acids in Rhodobacter capsulatus E1F1 cells, subjected to different treatments and nutritional conditions. Glutamine synthetase activity and enzyme concentration correlated negatively with the level of glutamine, suggesting that glutamine per se acts as a co-repressor in the enzyme synthesis. Moreover, addition of the specific inhibitor L-methionine-D,L-sulfoximine, that produced an increase in enzyme concentration, specifically promoted a depletion of intracellular glutamine.
Romero
F
F
Departamento de Bioquímica, Biología Molecular y Fisiología, Facultad de Ciencias, Universidad de Córdoba, Spain.
Quintero
A
A
Roldán
J M
JM
D004794:Enzyme Repression; D005974:Glutamate-Ammonia Ligase / Q000096:biosynthesis*; D005971:Glutamates / Q000502:physiology*; D018698:Glutamic Acid; D012241:Rhodopseudomonas / Q000201:enzymology*
D005971:Glutamates; D018698:Glutamic Acid; D005974:Glutamate-Ammonia Ligase