Download MendeleyCrystal structure of the plant GABA aminotransferase AtGABA-T from Arabidopsis thaliana.
Okoda, N., Okuda, S., Tsutsumi, K., Itoh, H., Okamoto, K., Kawakami, H., Sano, K., Kobata, K., Nagata, K.(2026) Acta Crystallogr F Struct Biol Commun 82: 208-215
- PubMed: 42065129 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1107/S2053230X26003456
- Primary Citation Related Structures:
21FT - PubMed Abstract:
γ-Aminobutyric acid aminotransferase (GABA-T) is a pyridoxal 5'-phosphate (PLP)-dependent enzyme that catalyzes γ-aminobutyric acid (GABA) degradation in the mitochondrial GABA shunt. Plant GABA-Ts correspond to EC 2.6.1.96 and differ from mammalian and bacterial GABA-Ts (EC 2.6.1.19) in substrate specificity; however, their structural basis has remained unclear. Here, we report the crystal structure of GABA aminotransferase from Arabidopsis thaliana (AtGABA-T) at 2.0 Å resolution. Structural comparison using Foldseek indicates that AtGABA-T belongs to the class III aminotransferase family. Comparison with a class III ω-aminotransferase suggests that Arg423 located in the C-terminal region of AtGABA-T functions as the primary anchor for the carboxyl group of GABA, together with residues forming a tunnel-shaped substrate-access pathway. In contrast to nonplant GABA aminotransferases, which utilize a conserved N-terminal arginine for substrate recognition, AtGABA-T employs a distinct C-terminal arginine. These findings provide direct structural evidence for the classification of AtGABA-T as a class III aminotransferase and reveal a distinct mode of substrate recognition in AtGABA-T.
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
Organizational Affiliation:
