Species: Escherichia coli K-12 substr. MG1655
Subunit composition of glutaminase B = [glutaminase B monomer]4
Two glutaminases were purified from E. coli B. They differ in their pH optima and regulation [Prusiner71]. Glutaminase B is active at neutral and alkaline pH [Prusiner76], and the enzyme is constitutive [Prusiner75].
Molecular Weight of Polypeptide: 22.5 kD (from nucleotide sequence)
Molecular Weight of Multimer: 90.0 kD (experimental) [Prusiner76]
pI: 5.4 [Prusiner76]
Enzymatic reaction of: glutaminase B
Synonyms: glutaminase, L-glutamine amidohydrolase
EC Number: 188.8.131.52
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
The reaction is physiologically favored in the direction shown.
Alternative Substrates [Comment 1]:
In Pathways: glutamine degradation I
Inhibitors (Unknown Mechanism): borate [Prusiner76a] , ATP [Prusiner76b] , ADP [Prusiner76b] , adenosine tetraphosphate [Prusiner76b] , NAD+ [Prusiner76b] , NADH [Prusiner76b] , NADP+ [Prusiner76b] , NADPH [Prusiner76b]
pH(opt): 7.1-9 [Prusiner76]
Prusiner76a: Prusiner S, Stadtman ER (1976). "Regulation of glutaminase B in Escherichia coli. II. Modulaltion of activity by carbosylate and borate ions." J Biol Chem 1976;251(11);3457-62. PMID: 776969
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