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B6db activities: 2.6.1.66

2.6.1.66
Description Valine--pyruvate aminotransferase.
Alternative names Transaminase C;
Alanine--valine transaminase;
Alanine-oxoisovalerate aminotransferase;
Alanine-ketoisovalerate transaminase;
AvtA.
Catalyzed reaction L-valine + pyruvate = 3-methyl-2-oxobutanoate + L-alanine.
Cofactor Pyridoxal-phosphate.
Comments -!- Different from EC 2.6.1.42.
These enzymes catalyze the transamination of L-valine, a reaction that is also catalyzed by branched-chain amino acid transaminases (EC 2.6.1.42). However, the known valine-pyruvate aminotransferases are fold-type I enzymes, whereas the enzymes in the 2.6.1.42 family are are fold-type IV. This may represent yet another instance of convergent evolution in PLP-dependent enzymes.

One gene product from C. glutamicum has recently been assigned to this activity, after some preliminary characterization. This Corynebacterium enzyme is also a fold-type I protein, but very different from the AvtA gene product from E. coli, and related to families 2.6.1.1_b and 2.6.1.57_b (aspartate aminotransferase and aromatic amino acid aminotransferase, respectively).

Organisms -Eubacteria
 

Family 

2.6.1.66 (13)
 
Links Enzyme (activities) 2.6.1.66
BRENDA (activities) 2.6.1.66
KEGG (pathways) 2.6.1.66
PLPMDB (PLP mutants) 2.6.1.66
 
References
 Marienhagen J, Kennerknecht N, Sahm H, Eggeling L. (2005) Functional analysis of all aminotransferase proteins inferred from the genome sequence of Corynebacterium glutamicum J Bacteriol 187 7639-46.

 Wang, M. D.; Liu, L.; Wang, B. M.; Berg, C. M. (1987) Cloning and characterization of the Escherichia coli K-12 alanine- valine transaminase (avtA) gene J Bacteriol 169 4228-34.

Articles on 2.6.1.66
 
last changed 2010/03/11 16:28

B6db activities