An evolved aminoacyl-tRNA synthetase with atypical polysubstrate specificity.
Biochemistry
; 50(11): 1894-900, 2011 Mar 22.
Article
en En
| MEDLINE
| ID: mdl-21280675
ABSTRACT
We have employed a rapid fluorescence-based screen to assess the polyspecificity of several aminoacyl-tRNA synthetases (aaRSs) against an array of unnatural amino acids. We discovered that a p-cyanophenylalanine specific aminoacyl-tRNA synthetase (pCNF-RS) has high substrate permissivity for unnatural amino acids, while maintaining its ability to discriminate against the 20 canonical amino acids. This orthogonal pCNF-RS, together with its cognate amber nonsense suppressor tRNA, is able to selectively incorporate 18 unnatural amino acids into proteins, including trifluoroketone-, alkynyl-, and halogen-substituted amino acids. In an attempt to improve our understanding of this polyspecificity, the X-ray crystal structure of the aaRS-p-cyanophenylalanine complex was determined. A comparison of this structure with those of other mutant aaRSs showed that both binding site size and other more subtle features control substrate polyspecificity.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Aminoacil-ARNt Sintetasas
Idioma:
En
Revista:
Biochemistry
Año:
2011
Tipo del documento:
Article
País de afiliación:
Estados Unidos