EC 2.6.1.15     
Accepted name: glutamine—pyruvate transaminase
Reaction: L-glutamine + pyruvate = 2-oxoglutaramate + L-alanine
Other name(s): glutaminase II; L-glutamine transaminase L; glutamine-oxo-acid transaminase
Systematic name: L-glutamine:pyruvate aminotransferase
Comments: A pyridoxal-phosphate protein. L-Methionine can act as donor; glyoxylate can act as acceptor.
References:
1.  Cooper, A.J.L. and Meister, A. Isolation and properties of highly purified glutamine transaminase. Biochemistry 11 (1972) 661–671. [PMID: 5059882]
2.  Meister, A. Studies on the mechanism and specificity of the glutamine-α-keto acid transamination-deamidation reaction. J. Biol. Chem. 210 (1954) 17–35. [PMID: 13201566]
[EC 2.6.1.15 created 1961]
 
 
EC 2.6.1.50     
Accepted name: glutamine—scyllo-inositol transaminase
Reaction: L-glutamine + 2,4,6/3,5-pentahydroxycyclohexanone = 2-oxoglutaramate + 1-amino-1-deoxy-scyllo-inositol
Other name(s): glutamine scyllo-inosose aminotransferase; L-glutamine-keto-scyllo-inositol aminotransferase; glutamine-scyllo-inosose transaminase; L-glutamine-scyllo-inosose transaminase
Systematic name: L-glutamine:2,4,6/3,5-pentahydroxycyclohexanone aminotransferase
Comments: A pyridoxal-phosphate protein.
References:
1.  Walker, J.B. and Walker, M.S. Streptomycin biosynthesis. Transamination reactions involving inosamines and inosadiamines. Biochemistry 8 (1969) 763–770. [PMID: 5781017]
[EC 2.6.1.50 created 1972]
 
 
EC 2.6.1.64     
Accepted name: glutamine—phenylpyruvate transaminase
Reaction: L-glutamine + phenylpyruvate = 2-oxoglutaramate + L-phenylalanine
Other name(s): glutamine transaminase K; glutamine-phenylpyruvate aminotransferase
Systematic name: L-glutamine:phenylpyruvate aminotransferase
Comments: A pyridoxal-phosphate protein. L-Methionine, L-histidine and L-tyrosine can act as donors. The enzyme has little activity on pyruvate and glyoxylate (cf. EC 2.6.1.15 glutamine—pyruvate transaminase).
References:
1.  Cooper, A.J.L. Purification of soluble and mitochondrial glutamine transaminase K from rat kidney. Use of a sensitive assay involving transamination between L-phenylalanine and α-keto-γ-methiolbutyrate. Anal. Biochem. 89 (1978) 451–460. [PMID: 727444]
2.  Cooper, A.J.L. and Meister, A. Isolation and properties of a new glutamine transaminase from rat kidney. J. Biol. Chem. 249 (1974) 2554–2561. [PMID: 4822504]
[EC 2.6.1.64 created 1984]
 
 
EC 2.6.1.100     
Accepted name: L-glutamine:2-deoxy-scyllo-inosose aminotransferase
Reaction: L-glutamine + 2-deoxy-scyllo-inosose = 2-oxoglutaramate + 2-deoxy-scyllo-inosamine
Glossary: 2-deoxy-scyllo-inosose = (2S,3R,4S,5R)-2,3,4,5-tetrahydroxycyclohexan-1-one
Other name(s): btrR (gene name); neoB (gene name); kanB (gene name)
Systematic name: L-glutamine:2-deoxy-scyllo-inosose aminotransferase
Comments: Involved in the biosynthetic pathways of several clinically important aminocyclitol antibiotics, including kanamycin, butirosin, neomycin and ribostamycin. Also catalyses EC 2.6.1.101, L-glutamine:5-amino-2,3,4-trihydroxycyclohexanone aminotransferase [2].
References:
1.  Tamegai, H., Eguchi, T. and Kakinuma, K. First identification of Streptomyces genes involved in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics--genetic and evolutionary analysis of L-glutamine:2-deoxy-scyllo-inosose aminotransferase genes. J. Antibiot. (Tokyo) 55 (2002) 1016–1018. [PMID: 12546424]
2.  Huang, F., Haydock, S.F., Mironenko, T., Spiteller, D., Li, Y. and Spencer, J.B. The neomycin biosynthetic gene cluster of Streptomyces fradiae NCIMB 8233: characterisation of an aminotransferase involved in the formation of 2-deoxystreptamine. Org. Biomol. Chem. 3 (2005) 1410–1418. [PMID: 15827636]
3.  Kudo, F., Yamamoto, Y., Yokoyama, K., Eguchi, T. and Kakinuma, K. Biosynthesis of 2-deoxystreptamine by three crucial enzymes in Streptomyces fradiae NBRC 12773. J. Antibiot. (Tokyo) 58 (2005) 766–774. [PMID: 16506694]
4.  Jnawali, H.N., Subba, B., Liou, K. and Sohng, J.K. Functional characterization of kanB by complementing in engineered Streptomyces fradiae Δneo6::tsr. Biotechnol. Lett. 31 (2009) 869–875. [PMID: 19219581]
[EC 2.6.1.100 created 2013]
 
 
EC 2.6.1.101     
Accepted name: L-glutamine:3-amino-2,3-dideoxy-scyllo-inosose aminotransferase
Reaction: L-glutamine + 3-amino-2,3-dideoxy-scyllo-inosose = 2-oxoglutaramate + 2-deoxystreptamine
Glossary: 3-amino-2,3-dideoxy-scyllo-inosose = (2R,3S,4R,5S)-5-amino-2,3,4-trihydroxycyclohexan-1-one
Systematic name: L-glutamine:5-amino-2,3,4-trihydroxycyclohexanone aminotransferase
Comments: Involved in the biosynthetic pathways of several clinically important aminocyclitol antibiotics, including kanamycin, butirosin, neomycin and ribostamycin. Also catalyses EC 2.6.1.100, L-glutamine:2-deoxy-scyllo-inosose aminotransferase.
References:
1.  Huang, F., Haydock, S.F., Mironenko, T., Spiteller, D., Li, Y. and Spencer, J.B. The neomycin biosynthetic gene cluster of Streptomyces fradiae NCIMB 8233: characterisation of an aminotransferase involved in the formation of 2-deoxystreptamine. Org. Biomol. Chem. 3 (2005) 1410–1418. [PMID: 15827636]
2.  Kudo, F., Yamamoto, Y., Yokoyama, K., Eguchi, T. and Kakinuma, K. Biosynthesis of 2-deoxystreptamine by three crucial enzymes in Streptomyces fradiae NBRC 12773. J. Antibiot. (Tokyo) 58 (2005) 766–774. [PMID: 16506694]
[EC 2.6.1.101 created 2013]
 
 
EC 2.6.1.117     
Accepted name: L-glutamine—4-(methylsulfanyl)-2-oxobutanoate aminotransferase
Reaction: L-glutamine + 4-(methylsulfanyl)-2-oxobutanoate = 2-oxoglutaramate + L-methionine
Other name(s): mtnE (gene name); Solyc11g013170.1 (locus name)
Systematic name: L-glutamine:4-(methylsulfanyl)-2-oxobutanoate aminotransferase
Comments: A pyridoxal-phosphate protein. The enzyme, found in both prokaryotes and eukaryotes, catalyses the last reaction in a methionine salvage pathway. In mammals this activity is catalysed by the multifunctional glutamine transaminase K (cf. EC 2.6.1.64, glutamine—phenylpyruvate transaminase).
References:
1.  Berger, B.J., English, S., Chan, G. and Knodel, M.H. Methionine regeneration and aminotransferases in Bacillus subtilis, Bacillus cereus, and Bacillus anthracis. J. Bacteriol. 185 (2003) 2418–2431. [PMID: 12670965]
2.  Ellens, K.W., Richardson, L.G., Frelin, O., Collins, J., Ribeiro, C.L., Hsieh, Y.F., Mullen, R.T. and Hanson, A.D. Evidence that glutamine transaminase and ω-amidase potentially act in tandem to close the methionine salvage cycle in bacteria and plants. Phytochemistry 113 (2015) 160–169. [PMID: 24837359]
[EC 2.6.1.117 created 2019]
 
 
EC 3.5.1.36     
Accepted name: N-methyl-2-oxoglutaramate hydrolase
Reaction: N-methyl-2-oxoglutaramate + H2O = 2-oxoglutarate + methylamine
Other name(s): 5-hydroxy-N-methylpyroglutamate synthase
Systematic name: N-methyl-2-oxoglutaramate methylamidohydrolase
Comments: In the reverse reaction, the product cyclizes non-enzymically to 2-hydroxy-N-methyl-5-oxo-L-proline.
References:
1.  Hersh, L.B. 5-Hydroxy-N-methylpyroglutamate synthetase. Purification and mechanism of action. J. Biol. Chem. 245 (1970) 3526–3535. [PMID: 5470822]
2.  Hersh, L.B., Tsai, L. and Stadtman, E.R. The enzymatic synthesis of 5-hydroxy-N-methylpyroglutamic acid. J. Biol. Chem. 244 (1969) 4677–4683. [PMID: 5808511]
[EC 3.5.1.36 created 1972]
 
 
EC 3.5.1.111     
Accepted name: 2-oxoglutaramate amidase
Reaction: 2-oxoglutaramate + H2O = 2-oxoglutarate + NH3
Glossary: 2-oxoglutaramate = 2-ketoglutaramate = 5-amino-2,5-dioxopentanoate
Other name(s): ω-amidase (ambiguous)
Systematic name: 5-amino-2,5-dioxopentanoate amidohydrolase
Comments: The enzyme, which is highly specific for its substrate, participates in the nicotine degradation pathway of several Gram-positive bacteria.
References:
1.  Cobzaru, C., Ganas, P., Mihasan, M., Schleberger, P. and Brandsch, R. Homologous gene clusters of nicotine catabolism, including a new ω-amidase for α-ketoglutaramate, in species of three genera of Gram-positive bacteria. Res. Microbiol. 162 (2011) 285–291. [PMID: 21288482]
[EC 3.5.1.111 created 2012]
 
 


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