4-aminobutyrate transaminase

In enzymology, a 4-aminobutyrate transaminase (EC 2.6.1.19) is an enzyme that catalyzes the chemical reaction

4-aminobutanoate + 2-oxoglutarate succinate semialdehyde + L-glutamate

Thus, the two substrates of this enzyme are 4-aminobutanoate and 2-oxoglutarate, whereas its two products are succinate semialdehyde and L-glutamate.

This enzyme belongs to the family of transferases, specifically the transaminases, which transfer nitrogenous groups. The systematic name of this enzyme class is 4-aminobutanoate:2-oxoglutarate aminotransferase. Other names in common use include beta-alanine-oxoglutarate transaminase, aminobutyrate aminotransferase, beta-alanine aminotransferase, beta-alanine-oxoglutarate aminotransferase, gamma-aminobutyrate aminotransaminase, gamma-aminobutyrate transaminase, gamma-aminobutyrate-alpha-ketoglutarate aminotransferase, gamma-aminobutyrate-alpha-ketoglutarate transaminase, gamma-aminobutyrate:alpha-oxoglutarate aminotransferase, gamma-aminobutyric acid aminotransferase, gamma-aminobutyric acid pyruvate transaminase, gamma-aminobutyric acid transaminase, gamma-aminobutyric acid-alpha-ketoglutarate transaminase, gamma-aminobutyric acid-alpha-ketoglutaric acid aminotransferase, gamma-aminobutyric acid-2-oxoglutarate transaminase, gamma-aminobutyric transaminase, 4-aminobutyrate aminotransferase, 4-aminobutyrate-2-ketoglutarate aminotransferase, 4-aminobutyrate-2-oxoglutarate aminotransferase, 4-aminobutyrate-2-oxoglutarate transaminase, 4-aminobutyric acid 2-ketoglutaric acid aminotransferase, 4-aminobutyric acid aminotransferase, aminobutyrate aminotransferase, aminobutyrate transaminase, GABA aminotransferase, GABA transaminase, GABA transferase, GABA-alpha-ketoglutarate aminotransferase, GABA-alpha-ketoglutarate transaminase, GABA-alpha-ketoglutaric acid transaminase, GABA-alpha-oxoglutarate aminotransferase, GABA-2-oxoglutarate aminotransferase, GABA-2-oxoglutarate transaminase, GABA-oxoglutarate aminotransferase, GABA-oxoglutarate transaminase, glutamate-succinic semialdehyde transaminase, and GabT. This enzyme participates in 5 metabolic pathways: glutamate metabolism, alanine and aspartate metabolism, beta-alanine metabolism, propanoate metabolism, and butanoate metabolism. It employs one cofactor, pyridoxal phosphate.

Structural studies

As of late 2007, 9 structures have been solved for this class of enzymes, with PDB accession codes 1OHV, 1OHW, 1OHY, 1SF2, 1SFF, 1SZK, 1SZS, 1SZU, and 2EO5.

References

• Scott EM, Jakoby WB (1959). "Soluble gamma-aminobutyric-glutamic transaminase from Pseudomonas fluorescens". J. Biol. Chem. 234 (4): 932–936. PMID 13654294. 
• Aurich H (1961). "Ueber die beta-Alanin-alpha-Ketoglutarat-Transaminase aus Neurospora crassa". Hoppe-Seyler's Z. Physiol. Chem. 326: 25–33. 
• Schousboe A, Wu JY, Roberts E (1973). "Purification and characterization of the 4-aminobutyrate:2-ketoglutarate transaminase from mouse brain". Biochemistry 12 (15): 2868–73. doi:10.1021/bi00739a015. PMID 4719123.