IUBMB Enzyme Nomenclature


Accepted name: diaminobutyrate—2-oxoglutarate transaminase

Reaction: L-2,4-diaminobutanoate + 2-oxoglutarate = L-aspartate 4-semialdehyde + L-glutamate

For diagram, click here

Other name(s): L-2,4-diaminobutyrate:2-ketoglutarate 4-aminotransferase; 2,4-diaminobutyrate 4-aminotransferase; diaminobutyrate aminotransferase; DABA aminotransferase; DAB aminotransferase; EctB; diaminibutyric acid aminotransferase; L-2,4-diaminobutyrate:2-oxoglutarate 4-aminotransferase

Systematic name: L-2,4-diaminobutanoate:2-oxoglutarate 4-aminotransferase

Comments: A pyridoxal-phosphate protein that requires potassium for activity [4]. In the proteobacterium Acinetobacter baumannii, this enzyme is cotranscribed with the neighbouring ddc gene that also encodes EC, diaminobutyrate decarboxylase. Differs from EC, diaminobutyrate—pyruvate transaminase, which has pyruvate as the amino-group acceptor. This is the first enzyme in the ectoine-biosynthesis pathway, the other enzymes involved being EC, diaminobutyrate acetyltransferase and EC, ectoine synthase [3,4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 196622-96-5


1. Ikai, H. and Yamamoto, S. Identification and analysis of a gene encoding L-2,4-diaminobutyrate:2-ketoglutarate 4-aminotransferase involved in the 1,3-diaminopropane production pathway in Acinetobacter baumannii. J. Bacteriol. 179 (1997) 5118-5125. [PMID: 9260954]

2. Ikai, H. and Yamamoto, S. Two genes involved in the 1,3-diaminopropane production pathway in Haemophilus influenzae. Biol. Pharm. Bull. 21 (1998) 170-173. [PMID: 9514614]

3. Peters, P., Galinski, E.A. and Truper, H.G. The biosynthesis of ectoine. FEMS Microbiol. Lett. 71 (1990) 157-162.

4. Ono, H., Sawada, K., Khunajakr, N., Tao, T., Yamamoto, M., Hiramoto, M., Shinmyo, A., Takano, M. and Murooka, Y. Characterization of biosynthetic enzymes for ectoine as a compatible solute in a moderately halophilic eubacterium, Halomonas elongata. J. Bacteriol. 181 (1999) 91-99. [PMID: 9864317]

5. Kuhlmann, A.U. and Bremer, E. Osmotically regulated synthesis of the compatible solute ectoine in Bacillus pasteurii and related Bacillus spp. Appl. Environ. Microbiol. 68 (2002) 772-783. [PMID: 11823218]

6. Louis, P. and Galinski, E.A. Characterization of genes for the biosynthesis of the compatible solute ectoine from Marinococcus halophilus and osmoregulated expression in Escherichia coli. Microbiology 143 (1997) 1141-1149. [PMID: 9141677]

[EC created 2000, modified 2006]

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