Transaminase that degrades gamma-amino butyric acid (GABA) and uses pyruvate or glyoxylate as amino-group acceptor. Cannot use beta-alanine, ornithine, acetylornithine, serine, glycine, asparagine, glutamine, glutamate, valine, leucine, isoleucine, methionine, phenylalanine, histidine, lysine, arginine, aspartate, threonine, tyrosine, tryptophan, proline, or cysteine as amino donors. May be responsible for establishing the GABA gradient in the carpel. 4-aminobutanoate + pyruvate = L-alanine + succinate semialdehyde 4-aminobutanoate + glyoxylate = glycine + succinate semialdehyde Expressed in leaves, roots, stems, flowers and fruits. Expressed in carpels, but not in stamens. Loss of expression in the yellow and red fruits, after the breaker stage. Belongs to the class-III pyridoxal-phosphate-dependent aminotransferase family.