Characterization and crystal structure of lysine insensitive Corynebacterium glutamicum dihydrodipicolinate synthase (cDHDPS) protein.
Arch Biochem Biophys
; 480(2): 111-21, 2008 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-18930704
ABSTRACT
The lysine insensitive Corynebacterium glutamicum dihydrodipicolinate synthase enzyme (cDHDPS) was recently successfully introduced into maize plants to enhance the level of lysine in the grain. To better understand lysine insensitivity of the cDHDPS, we expressed, purified, kinetically characterized the protein, and solved its X-ray crystal structure. The cDHDPS enzyme has a fold and overall structure that is highly similar to other DHDPS proteins. A noteworthy feature of the active site is the evidence that the catalytic lysine residue forms a Schiff base adduct with pyruvate. Analyses of the cDHDPS structure in the vicinity of the putative binding site for S-lysine revealed that the allosteric binding site in the Escherichia coli DHDPS protein does not exist in cDHDPS due to three non-conservative amino acids substitutions, and this is likely why cDHDPS is not feedback inhibited by lysine.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Corynebacterium glutamicum
/
Hidroliases
/
Lisina
Limite:
Humans
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article