This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.
|Superclasses:||Degradation/Utilization/Assimilation → Amino Acids Degradation → Proteinogenic Amino Acids Degradation → L-glutamine Degradation|
L-glutamine is the amino group donor for many cellular biosynthetic reactions and serves as a storage reservoir of ammonia, playing an important role in nitrogen metabolism. In eukaryotes, L-glutamine is converted to L-glutamate by glutaminase, the enzyme responsible for L-glutamine catabolism. In plants, bacteria, and archaea, L-glutamine can also be converted to L-glutamate by the reversible glutamate synthase reaction, also known as GOGAT for glutamine: α-oxoglutarate aminotransferase (see pathway L-glutamine degradation II). [Voet04, Gottschalk86]
About This Pathway
Wild-type Escherichia coli K-12 grows only poorly on L-glutamine as the sole source of carbon, although mutants that gain the ability to utilize L-glutamine can be isolated easily [Masters81]. In contrast, L-glutamine supports rapid growth as the sole source of nitrogen, although growth is biphasic with a transition in mid-log phase [Atkinson02a]. No mutants unable to utilize L-glutamine as the sole source of nitrogen have been identified.
Two enzymes able to degrade L-glutamine, glutaminase and glutaminase B, were purified from Escherichia coli B; no mutants were identified at the time, and thus the identity of the genes encoding them has not been established. Recently, two genes encoding glutaminases with properties resembling those of glutaminase A and B have been identified in Escherichia coli K-12 [Brown08]. Reviewed in Reitzer, L., Catabolism of Amino Acids and Related Compounds, Module 3.4.7 [ECOSAL].
Variants: L-glutamine degradation II
Unification Links: EcoCyc:GLUTAMINDEG-PWY
Atkinson02a: Atkinson MR, Blauwkamp TA, Bondarenko V, Studitsky V, Ninfa AJ (2002). "Activation of the glnA, glnK, and nac promoters as Escherichia coli undergoes the transition from nitrogen excess growth to nitrogen starvation." J Bacteriol 184(19);5358-63. PMID: 12218022
Brown08: Brown G, Singer A, Proudfoot M, Skarina T, Kim Y, Chang C, Dementieva I, Kuznetsova E, Gonzalez CF, Joachimiak A, Savchenko A, Yakunin AF (2008). "Functional and structural characterization of four glutaminases from Escherichia coli and Bacillus subtilis." Biochemistry 47(21);5724-35. PMID: 18459799
Abbott06: Abbott JL, Newell JM, Lightcap CM, Olanich ME, Loughlin DT, Weller MA, Lam G, Pollack S, Patton WA (2006). "The Effects of Removing the GAT Domain from E. coli GMP Synthetase." Protein J 25;483-491. PMID: 17103135
Aledo00: Aledo JC, Gomez-Fabre PM, Olalla L, Marquez J (2000). "Identification of two human glutaminase loci and tissue-specific expression of the two related genes." Mamm Genome 11(12);1107-10. PMID: 11130979
Anderson83: Anderson PM (1983). "CTP synthetase from Escherichia coli: an improved purification procedure and characterization of hysteretic and enzyme concentration effects on kinetic properties." Biochemistry 22(13);3285-92. PMID: 6349684
Arifuzzaman06: Arifuzzaman M, Maeda M, Itoh A, Nishikata K, Takita C, Saito R, Ara T, Nakahigashi K, Huang HC, Hirai A, Tsuzuki K, Nakamura S, Altaf-Ul-Amin M, Oshima T, Baba T, Yamamoto N, Kawamura T, Ioka-Nakamichi T, Kitagawa M, Tomita M, Kanaya S, Wada C, Mori H (2006). "Large-scale identification of protein-protein interaction of Escherichia coli K-12." Genome Res 16(5);686-91. PMID: 16606699
Bearne01: Bearne SL, Hekmat O, Macdonnell JE (2001). "Inhibition of Escherichia coli CTP synthase by glutamate gamma-semialdehyde and the role of the allosteric effector GTP in glutamine hydrolysis." Biochem J 356(Pt 1);223-32. PMID: 11336655
Boehlein94: Boehlein SK, Richards NG, Schuster SM (1994). "Glutamine-dependent nitrogen transfer in Escherichia coli asparagine synthetase B. Searching for the catalytic triad." J Biol Chem 269(10);7450-7. PMID: 7907328
Butland05: Butland G, Peregrin-Alvarez JM, Li J, Yang W, Yang X, Canadien V, Starostine A, Richards D, Beattie B, Krogan N, Davey M, Parkinson J, Greenblatt J, Emili A (2005). "Interaction network containing conserved and essential protein complexes in Escherichia coli." Nature 433(7025);531-7. PMID: 15690043
Cedar69: Cedar H, Schwartz JH (1969). "The asparagine synthetase of Escherhic coli. I. Biosynthetic role of the enzyme, purification, and characterization of the reaction products." J Biol Chem 1969;244(15);4112-21. PMID: 4895361
Chen89b: Chen KC, Vannais DB, Jones C, Patterson D, Davidson JN (1989). "Mapping of the gene encoding the multifunctional protein carrying out the first three steps of pyrimidine biosynthesis to human chromosome 2." Hum Genet 82(1);40-4. PMID: 2565865
ChungBok97: Chung-Bok MI, Vincent N, Jhala U, Watford M (1997). "Rat hepatic glutaminase: identification of the full coding sequence and characterization of a functional promoter." Biochem J 324 ( Pt 1);193-200. PMID: 9164856
Ciustea05: Ciustea M, Gutierrez JA, Abbatiello SE, Eyler JR, Richards NG (2005). "Efficient expression, purification, and characterization of C-terminally tagged, recombinant human asparagine synthetase." Arch Biochem Biophys 440(1);18-27. PMID: 16023613
Coleman77: Coleman PF, Suttle DP, Stark GR (1977). "Purification from hamster cells of the multifunctional protein that initiates de novo synthesis of pyrimidine nucleotides." J Biol Chem 252(18);6379-85. PMID: 19472
Davidson90a: Davidson JN, Rao GN, Niswander L, Andreano C, Tamer C, Chen KC (1990). "Organization and nucleotide sequence of the 3' end of the human CAD gene." DNA Cell Biol 9(9);667-76. PMID: 1979741
Delannay99: Delannay S, Charlier D, Tricot C, Villeret V, Pierard A, Stalon V (1999). "Serine 948 and threonine 1042 are crucial residues for allosteric regulation of Escherichia coli carbamoylphosphate synthetase and illustrate coupling effects of activation and inhibition pathways." J Mol Biol 286(4);1217-28. PMID: 10047492
Deras99: Deras ML, Chittur SV, Davisson VJ (1999). "N2-hydroxyguanosine 5'-monophosphate is a time-dependent inhibitor of Escherichia coli guanosine monophosphate synthetase." Biochemistry 38(1);303-10. PMID: 9890911
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