Branched chain amino acid transaminase 2 | Branched-chain-amino-acid transaminase | IUPHAR/BPS Guide to PHARMACOLOGY

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Branched chain amino acid transaminase 2

Target not currently curated in GtoImmuPdb

Target id: 2893

Nomenclature: Branched chain amino acid transaminase 2

Family: Branched-chain-amino-acid transaminase

Gene and Protein Information
Species TM AA Chromosomal Location Gene Symbol Gene Name Reference
Human - 392 19q13.33 BCAT2 branched chain amino acid transaminase 2 1
Mouse - 393 7 B4 Bcat2 branched chain aminotransferase 2
Rat - 393 1q22 Bcat2 branched chain amino acid transaminase 2 1
Gene and Protein Information Comments
For the human gene and protein we provide details for the longest form, isoform a (from transcript variant a) also known as PP18a. Isoforms b and c (PP18b, PP18c) are shorter at 300 and 352 amino acids (aa) respectively. Two mouse isoforms are produced from 3 transcript variants. Isoform 1 is the longest (details in the table), with isoform 2 having a shorter N-terminus (353 aa).
Previous and Unofficial Names
branched-chain-amino-acid aminotransferase, mitochondrial | BCATm | BCAM | BCT2 | Eca40 (Mm) | Bcat-2 | mBcat | branched chain aminotransferase 2, mitochondrial | branched chain aminotransferase 2
Database Links
ChEMBL Target
Ensembl Gene
Entrez Gene
Human Protein Atlas
KEGG Enzyme
RefSeq Nucleotide
RefSeq Protein
Selected 3D Structures
Image of receptor 3D structure from RCSB PDB
Description:  X-ray crystal structure at 1.65A resolution of human mitochondrial branched chain aminotransferase (BCATm) complexed with a thiazole compound and pmp cofactor.
PDB Id:  5I5X
Ligand:  compound 27 [PMID: 26938474]
Resolution:  1.65Å
Species:  Human
References:  2
Enzyme Reaction
EC Number:
Description Reaction Reference
L-leucine + 2-oxoglutarate <=> 4-methyl-2-oxopentanoate + L-glutamate
L-isoleucine + 2-oxoglutarate <=> (S)-3-methyl-2-oxopentanoate + L-glutamate
L-valine + 2-oxoglutarate <=> 3-methyl-2-oxobutanoate + L-glutamate

Download all structure-activity data for this target as a CSV file

Key to terms and symbols View all chemical structures Click column headers to sort
Ligand Sp. Action Value Parameter Reference
compound 27 [PMID: 26938474] Hs Inhibition 6.7 pIC50 2
pIC50 6.7 (IC50 1.99x10-7 M) [2]
compound 42 [PMID: 26938474] Hs Inhibition 5.8 pIC50 2
pIC50 5.8 (IC50 1.585x10-6 M) [2]
Immuno Process Associations
Immuno Process:  Cytokine production & signalling
GO Annotations:  Associated to 1 GO processes, IEA only
click arrow to show/hide IEA associations
GO:1990830 cellular response to leukemia inhibitory factor IEA
Tissue Distribution Comments
In mammals, BCAT2 (BCATm) is expressed in most tissues [3]. In comparison, expression of the cytosilic isozyme BCAT1 (BCATc; UniProt P54687) is restricted to the CNS.
Physiological Consequences of Altering Gene Expression
Bcat2 knockout mice are resistant to high-fat diet induced obesity and diabetes
Species:  Mouse
Technique:  Gene knockout
References:  4
General Comments
BCAT2 is a mitochondrial protein that catalyses the first step in the production of the branched chain amino acids leucine, isoleucine, and valine.
HGNC places this protein in the minor histocompatibility antigen (MHA) family. MHAs are known to induce an immunological response in some organ transplants, albeit to a much lesser degree than the major histocompatibility complex (MHC) antigens. Amino acid differences in MHAs can cause slow rejection of transplanted organs even when MHCs are comprehensively matched between donor and recipient.


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1. Bledsoe RK, Dawson PA, Hutson SM. (1997) Cloning of the rat and human mitochondrial branched chain aminotransferases (BCATm). Biochim. Biophys. Acta, 1339 (1): 9-13. [PMID:9165094]

2. Borthwick JA, Ancellin N, Bertrand SM, Bingham RP, Carter PS, Chung CW, Churcher I, Dodic N, Fournier C, Francis PL et al.. (2016) Structurally Diverse Mitochondrial Branched Chain Aminotransferase (BCATm) Leads with Varying Binding Modes Identified by Fragment Screening. J. Med. Chem., 59 (6): 2452-67. [PMID:26938474]

3. Hutson S. (2001) Structure and function of branched chain aminotransferases. Prog. Nucleic Acid Res. Mol. Biol., 70: 175-206. [PMID:11642362]

4. She P, Reid TM, Bronson SK, Vary TC, Hajnal A, Lynch CJ, Hutson SM. (2007) Disruption of BCATm in mice leads to increased energy expenditure associated with the activation of a futile protein turnover cycle. Cell Metab., 6 (3): 181-94. [PMID:17767905]

How to cite this page Branched-chain-amino-acid transaminase: Branched chain amino acid transaminase 2. Last modified on 21/03/2017. Accessed on 25/09/2020. IUPHAR/BPS Guide to PHARMACOLOGY,