Download MendeleyAn Evolved Aminoacyl-tRNA Synthetase with Atypical Polysubstrate Specificity .
Young, D.D., Young, T.S., Jahnz, M., Ahmad, I., Spraggon, G., Schultz, P.G.(2011) Biochemistry 50: 1894-1900
- PubMed: 21280675
- DOI: https://doi.org/10.1021/bi101929e
- Primary Citation of Related Structures:
3QE4 - PubMed 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.
Organizational Affiliation:
Department of Chemistry and Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States.
