Gene: [12p1/BCAT1] branched chain aminotransferase 1, cytosolic; transaminase 1 of branched chain amino acids (BCAA); hyperleucinemia-isoleucinemia (BCAA transaminase 1 deficiency);


COM

[1] The Enzymes Nomenclature registered three enzymes that have similar function but more narrow substrate specificity, as compared to thiose of AAP. These are 2.6.1.6 - leucine aminotransferase, 2.6.1.32 - valine-3-methyl-2-oxovalerate aminotransferase or valine-isoleucine aminotransferase, and 2.6.1.66 - valine-pyruvate aminotransferase (transaminase C).
[2] All HGM catalogues (since HGM5-1979) and GDB erroneously indicate code EC:2.6.1.26 for branched-chain amino acid transferases; this code actually corresponds to another enzyme, thyroid-hormone aminotransferase."

FUN

Systematic name: branched-chain-amino-acid:2-oxoglutarate aminotransferase. The catalyzed reaction: L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate. Other substrates are L-isoleucine and L-valine."

FAG

A gene for AAP-2 isoenzyme is mapped in Chr 19 (GEM:19^/BCAT2).

HET

[1] Among all diseases that are related with the accumulation of branched-chain amino acids, isolated hypervalinemia is the most well-studied (MIM:277100; Wada-1963; Dancis-1967; Tada-1967). The disease is thought to be determined by an isolated defect of valine transamination. The defect is possibly accounted for by either deficiency of yet unidentified valine aminitransferase or a mutation in the AAP active center that impedes binding of valine but not leucine and isoleucine.
[2] A case of familial pathology with accumulation of isoleucine, leucine, and proline accumulation but normal valine level (hyperleucinme-isoleucinemia; MIM:238340) was described (Jeune-1970). This disease is assumed to be caused by at least two independent genetic defects - AAP deficiency and disturbance of proline degradation."

REF

PAT,PHE,MEB,FOG "Dancis, Levitz: (in) MBID, 4th ed, pp.397-410, 1978
HET,PHE,PAT "Dancis &: Pediatrics, 39, 813-817, 1967
CLO,SEQ "Eden A &: JBC, 271, N34, 20242-20245, 1996
FUN,PEP "Goto &: Gann, 68, 663-667, 1977
PAT,PHE,MEB,FOG "Jeune &: Ann Pediatr, 17, 85-99, 1970
LOC,CYG "Jones C, Moore: Hum Genet, 66, 206-211, 1984
LOC,CYG "Jones C, Moore: CCG, 25, (HGM5), 168, 1979
LOC,CYG "Naylor SL, Shows: Somat Cell Genet, 6, N5, 641-652, 1980
LOC,CYG "Naylor SL, Shows: CCG, 25, (HGM5), 191-192, 1979
HET,PHE,PAT "Tada &: Am J Dis Child, 113, 64-67, 1967
HET,PHE,PAT "Wada &: Tohoku J Exp Med, 81, 46-55, 1963

SWI

SWISSPROT: P54687

KEY

aac, mtbd

CLA

coding, basic

LOC

12 p1

MIM

MIM: 113520

EZN

ENZYME: 2.6.1.42