Mechanism of molecular interactions for tRNA(Val) recognition by valyl-tRNA synthetase.
RNA
; 9(1): 100-11, 2003 Jan.
Article
en En
| MEDLINE
| ID: mdl-12554880
ABSTRACT
The molecular interactions between valyl-tRNA synthetase (ValRS) and tRNA(Val), with the C34-A35-C36 anticodon, from Thermus thermophilus were studied by crystallographic analysis and structure-based mutagenesis. In the ValRS-bound structure of tRNA(Val), the successive A35-C36 residues (the major identity elements) of tRNA(Val) are base-stacked upon each other, and fit into a pocket on the alpha-helix bundle domain of ValRS. Hydrogen bonds are formed between ValRS and A35-C36 of tRNA(Val) in a base-specific manner. The C-terminal coiled-coil domain of ValRS interacts electrostatically with A20 and hydrophobically with the G19*C56 tertiary base pair. The loss of these interactions by the deletion of the coiled-coil domain of ValRS increased the K(M) value for tRNA(Val) 28-fold and decreased the k(cat) value 19-fold in the aminoacylation. The tRNA(Val) K(M) and k(cat) values were increased 21-fold and decreased 32-fold, respectively, by the disruption of the G18*U55 and G19*C56 tertiary base pairs, which associate the D- and T-loops for the formation of the L-shaped tRNA structure. Therefore, the coiled-coil domain of ValRS is likely to stabilize the L-shaped tRNA structure during the aminoacylation reaction.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Valina-ARNt Ligasa
/
ARN de Transferencia de Valina
Idioma:
En
Revista:
RNA
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2003
Tipo del documento:
Article
País de afiliación:
Japón