IUBMB Enzyme Nomenclature


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, glutamine–phenylpyruvate transaminase).

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


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 created 2019]

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