Reaction: (1) 4-aminobutanoate + pyruvate = succinate semialdehyde + L-alanine
(2) 4-aminobutanoate + glyoxylate = succinate semialdehyde + glycine
Other name(s): aminobutyrate aminotransferase (ambiguous); γ-aminobutyrate aminotransaminase (ambiguous); γ-aminobutyrate transaminase (ambiguous); γ-aminobutyric acid aminotransferase (ambiguous); γ-aminobutyric acid pyruvate transaminase; γ-aminobutyric acid transaminase (ambiguous); γ-aminobutyric transaminase (ambiguous); 4-aminobutyrate aminotransferase (ambiguous); 4-aminobutyric acid aminotransferase (ambiguous); aminobutyrate transaminase (ambiguous); GABA aminotransferase (ambiguous); GABA transaminase (ambiguous); GABA transferase (ambiguous); POP2 (gene name)
Systematic name: 4-aminobutanoate:pyruvate aminotransferase
Comments: Requires pyridoxal 5'-phosphate. The enzyme is found in plants that do not have the 2-oxoglutarate dependent enzyme (cf. EC 2.6.1.19). The reaction with pyruvate is reversible while the reaction with glyoxylate only takes place in the forward direction.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Van Cauwenberghe, O.R. and Shelp, B.J. Biochemical characterization of partially purified gaba:pyruvate transaminase from Nicotiana tabacum. Phytochemistry 52 (1999) 575-581.
2. Palanivelu, R., Brass, L., Edlund, A.F. and Preuss, D. Pollen tube growth and guidance is regulated by POP2, an Arabidopsis gene that controls GABA levels. Cell 114 (2003) 47-59. [PMID: 12859897]
3. Clark, S.M., Di Leo, R., Dhanoa, P.K., Van Cauwenberghe, O.R., Mullen, R.T. and Shelp, B.J. Biochemical characterization, mitochondrial localization, expression, and potential functions for an Arabidopsis γ-aminobutyrate transaminase that utilizes both pyruvate and glyoxylate. J. Exp. Bot. 60 (2009) 1743-1757. [PMID: 19264755]
4. Clark, S.M., Di Leo, R., Van Cauwenberghe, O.R., Mullen, R.T. and Shelp, B.J. Subcellular localization and expression of multiple tomato γ-aminobutyrate transaminases that utilize both pyruvate and glyoxylate. J. Exp. Bot. 60 (2009) 3255-3267. [PMID: 19470656]