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{{enzyme
| Name = 4-aminobutyrate transaminase
| EC_number = 2.6.1.19
| CAS_number = 9037-67-6
| IUBMB_EC_number = 2/6/1/19
| GO_code = 0003867
| image = 
| width = 
| caption = 
}}
{{protein
|Name=4-aminobutyrate transaminase
|caption=
|image=
|width=
|HGNCid=23
|Symbol=ABAT
|AltSymbols=
|EntrezGene=18
|OMIM=137150
|RefSeq=NM_020686
|UniProt=P80404
|PDB=
|ECnumber=
|Chromosome=16
|Arm=p
|Band=13.2
|LocusSupplementaryData=
}}
In [[enzymology]], '''4-aminobutyrate transaminase''' ({{EC number|2.6.1.19}}), also called '''GABA transaminase''' or '''4-aminobutyrate aminotransferase''', is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]:

:4-aminobutanoate + 2-oxoglutarate <math>\rightleftharpoons</math> succinate semialdehyde + L-glutamate

Thus, the two [[substrate (biochemistry)|substrates]] of this enzyme are [[4-aminobutanoate]] ([[GABA]]) and [[2-oxoglutarate]]. The two [[product (chemistry)|products]] are [[succinate semialdehyde]] and [[L-glutamate]].

This enzyme belongs to the family of [[transferase]]s, specifically the [[transaminases]], which transfer nitrogenous groups.  The systematic name of this enzyme class is '''4-aminobutanoate:2-oxoglutarate aminotransferase'''. This enzyme participates in 5 metabolic pathways: alanine and aspartate [[metabolism]], [[glutamate metabolism]], [[beta-alanine metabolism]], [[propanoate metabolism]], and [[butyric acid|butanoate metabolism]].  It employs one [[cofactor (biochemistry)|cofactor]], [[pyridoxal phosphate]].

== Structural Studies ==

As of late 2007, 9 [[tertiary structure|structures]] have been solved for this class of enzymes, with [[Protein Data Bank|PDB]] accession codes {{PDB link|1OHV}}, {{PDB link|1OHW}}, {{PDB link|1OHY}}, {{PDB link|1SF2}}, {{PDB link|1SFF}}, {{PDB link|1SZK}}, {{PDB link|1SZS}}, {{PDB link|1SZU}}, and {{PDB link|2EO5}}.

== Inhibitors ==
* [[Aminooxyacetic acid]]
* [[Gabaculine]]
* [[Phenelzine]]
* [[Phenylethylidenehydrazine]] (PEH)
* [[Rosmarinic acid]]<ref>Bioassay-guided fractionation of lemon balm (Melissa officinalis L.) using an in vitro measure of GABA transaminase activity. Awad R, Muhammad A, Durst T, Trudeau VL and Arnason JT, Phytother Res., August 2009, volume 23, issue 8, pages 1075-1081, {{doi|10.1002/ptr.2712}}</ref>
* [[Valproic acid]]
* [[Vigabatrin]]

==References==
{{reflist|1}}
* {{cite journal | author = Scott EM, Jakoby WB | date = 1959 | title = Soluble gamma-aminobutyric-glutamic transaminase from Pseudomonas fluorescens | journal = J. Biol. Chem.  | volume = 234 | pages = 932&ndash;936  | pmid = 13654294 | issue = 4 }}
* {{cite journal | author = Aurich H | date = 1961 | title = Ueber die beta-Alanin-alpha-Ketoglutarat-Transaminase aus Neurospora crassa | journal = Hoppe-Seyler's Z. Physiol. Chem.  | volume = 326 | pages = 25&ndash;33 }}
* {{cite journal | author = Schousboe A, Wu JY, Roberts E | date = 1973 | title = Purification and characterization of the 4-aminobutyrate:2-ketoglutarate transaminase from mouse brain | journal = Biochemistry | volume = 12 | pages = 2868&ndash;73  | pmid = 4719123 | doi = 10.1021/bi00739a015 | issue = 15 }}

==External links==
* {{MeshName|4-Aminobutyrate+Transaminase}}


{{Neurotransmitter metabolism enzymes}}
[[Category:EC 2.6.1]]
[[Category:Pyridoxal phosphate enzymes]]
[[Category:Enzymes of known structure]]